Airfield winter maintenance plan. Prospects for the development of the aviation industry
5.1.1. When performing airfield maintenance work in the summer, it is necessary to ensure performance airfield pavements: flatness; friction properties; surface cleanliness; preservation of design geometric shapes and sizes.
5.1.2. It is recommended to draw up plans for the operational maintenance of airfield elements with the allocation of forces and means, first of all, for the most labor-intensive and critical work that requires the greatest mechanization.
5.1.3. Mechanization means should be used in accordance with the principles of technology, which are based on patrolling of harvesting machines with a rational selection of types of machines and their squad and optimal routes for their movement.
5.1.4. Operational maintenance of airfields during the summer period includes:
Cleaning artificial surfaces from dust, dirt, debris and other foreign objects;
Removing damaged and peeling sealant and sealing (filling) seams and cracks with new sealant;
Current and major repairs of airfield pavement elements;
Updating of daytime markings of coverings and portable markings;
Maintaining the levelness and uniform strength of the soil part of the airfield;
Sodding of destroyed turf cover with elimination of ruts and potholes; carrying out measures to strengthen the soils of the working part of the airfields and ensure their erosion resistance; dust removal of the airfield surface;
Maintaining the grass stand at the established height and quality;
Ensuring surface water flow from the airfield and its structures and the capacity of drainage and drainage devices;
Removing rubber deposits, bitumen and oil stains, etc. surface contaminants.
5.1.5. The nature of cleaning work is largely determined by the planning decision of a particular airport, the parameters of aircraft and transport movement on the airfield and the climatic conditions of the area.
5.1.6. For better organization of work on mechanized cleaning of airfield surfaces, it is recommended to divide the territory into separate sections (zones) served by a mechanized column. To do this you should:
Establish the scope of work and the number of machines to perform it;
Develop technological maps with harvesting modes in accordance with available equipment, taking into account local conditions;
Establish route diagrams for the movement of cleaning equipment and work schedules.
5.1.7. The organization of work is carried out through the airfield service dispatcher, who must ensure:
Monitoring the release of vehicles onto the airfield, periodically checking their location;
Prompt redistribution of vehicles in cases of instructions from the RPA, the traffic controller (SDP MVL), the head of the airfield service, taking into account changes in their working conditions.
5.1.8. The cleanliness of the surface of artificial airfield pavements is maintained by regular sweeping and blowing with brush-pneumatic (wind) machines, removal of foreign objects with electromagnetic cleaners, and vacuum machines (vacuum cleaners).
5.1.9. To ensure the technology for patrol cleaning of coatings in the “windows” between flights, it is recommended to calculate the required minimum time interval for carrying out work using formula 5.4.
5.1.10. The basic principles and criteria for selecting a squad of harvesting machines are as follows:
The number of ruts should be minimal;
The width of the entire squad of vehicles must be a multiple of the width of the main elements of the airfield to be cleared (runway, MRR, taxiway);
Taking into account the geometry and relative position of the elements of the airfield and the average maneuvering time of the squad vehicles (it is recommended to determine the maneuvering time as the weighted average of the time spent on all turns and turns of the vehicles along the route, taking into account the reduction and subsequent increase in speed to the operating speed after maneuvering).
5.1.11. Measures to prevent the entry of foreign objects into engines come down to monitoring the cleanliness and cleaning of coatings.
5.1.12. The frequency of cleaning of coatings depends on local conditions and operating experience of the airfield.
5.1.13. Aprons and MS are generally more contaminated than other artificial surfaces.
5.1.14. To reduce the destruction of the surface layer of cement concrete pavements, it is recommended to treat them with solutions of synthetic substances. The most widely used treatment is the treatment of the surface of airfield coatings with petroleum-polymer paint and varnish resin (NLS) grade B, diluted with a solvent in a ratio of 1: 4.7. To impregnate the surface of coatings, green oil concentrate or impregnating compositions based on petroleum-polymer resins of the SIS type (styrene-indene resin) can also be used. Consumption of solutions - 150 g/sq.m.
The volume of the composition that must be distributed over the treated area of the airfield pavement is determined using the formula:
where is the volume of bridging composition, cubic meters;
Area of processed coating elements, sq.m;
Consumption rate of the composition, g/sq.m;
Composition density, t/cub.m;
The capacity of the tank of spilling agents is determined by the formula:
, (5.2)
where is the capacity of the dispensing agent tank, cubic meters;
Operating width of the processing machine (device) when performing work for specific conditions, m;
Overlapping width of adjacent passages of processing machines (devices), m;
Width of the treated area, m;
Number of runs of machines (devices) for surface treatment.
The number of machines for processing coatings with compounds is selected in such a way that the amount of overlap is minimal;
The number of funds in a squad is calculated using the formula
, (5.3)
5.1.16. It is necessary to restore the original roughness of the coating surface in areas contaminated with lubricants, chemical deicing agents, marking paint, rubber deposits, etc.
5.1.17. It is recommended to remove rubber deposits using a chemical method and mechanically by milling and using high-pressure water jets.
Rubber deposits are removed by milling using special mechanical equipment - a milling cutter. Sweepers remove dust and rubber residues after this treatment. The productivity of this method can reach 500 sq.m/h.
When using the method of removing rubber deposits with a jet of water under high pressure (up to 40 MPa), which is provided by special equipment, an area of 250 - 800 sq.m is processed in an hour at a water flow rate of up to 1000 l/min.
With the chemical method, rubber is dissolved, then the destruction products are washed off with water, swept with cleaning machines or removed with vacuum cleaners.
5.1.18. Contaminants from spilled fuels and lubricants are removed by spraying substances that dissolve fuel and oils, followed by removal of reaction products. The contaminated area is treated with an oil-absorbing substance, then cleaned and swept. When cleaning coatings with chemicals, environmental protection measures must be taken.
5.1.19. The main technological operations of summer cleaning of artificial surfaces are sweeping and washing. The frequency of such work is established depending on the degree of contamination of areas and elements of the airfield.
5.1.20. Cleaning the surface of artificial surfaces is carried out by a detachment of sweeping machines moving with a ledge at a distance of 10 - 20 m from each other. The overlap of sweeping strips must be at least 0.5 m.
The efficiency of machines is determined to a large extent by the condition of their working parts, operating modes and adjustments. Requirements for the quality of cleaning of coatings by means of mechanization and methods for monitoring the effectiveness of their working parts are given in the appendix. 8.
When sweeping, jets of water coming out of the nozzles with a flow rate of up to 0.03 l/sq.m should be evenly sprayed and overlapped at the surface of the coating.
The deformation of the pile of cylindrical brushes pressed to the coating should be the same along the entire length of the brush and be 15-20 mm. The length of the pile of a cylindrical brush should be in the range of 60-180mm.
5.1.21. When sweeping, it is recommended to select the operating speed of sweeping machines taking into account the contamination of the surface: for heavy contamination 5 - 6 km/h, and under normal conditions 10 - 15 km/h.
5.1.22. After the end of the spring thaw, it is recommended to wash artificial surfaces that are in good condition.
Washing consists of two simultaneous processes: separation of dust and contaminants from the surface of coatings and their movement in the direction of longitudinal and transverse slopes towards the water intake structure. Water consumption when washing should be at least 0.8 - 1.1 l/sq.m. Washing should be done downhill.
5.1.23. Washing of the coatings is carried out by a detachment of watering machines, and the distance of the machines from each other is 10 - 20 m. It is recommended that the machines move in a ledge with an overlap of the processed strips by 0.7 - 1.0 m.
5.1.24. The quality of washing the surface of coatings depends on the correct installation of washing attachments - nozzles. During the adjustment process, the nozzles are rotated in horizontal and vertical planes using installation cones mounted on the pressure pipeline.
5.1.25. Dust and debris washed off the surface of coatings with water and entering the drainage system must be periodically cleaned.
5.1.26. In the summer, daytime markings must be applied at airfields in accordance with the requirements of Chapter. 3 of this Guide.
The technology for marking airfields (heliports) and landing sites is given in Section. 3.5 of this Guide.
Daytime markings must be cleaned of dust, dirt, and updated as they wear out, rub off with rubber, and paint coatings fade.
Portable marking signs should be repaired as their structures are destroyed or worn out and their color renewed. The characteristics of paints and varnishes for marking airfield pavements and portable markings are given in Appendix 14.
5.1.27. Renewal of markings must be carried out at least twice a year, and as a rule, in spring and autumn.
5.1.28. Restoring the tightness of seams is carried out systematically by replacing the failed filler with new material.
Before filling the seam, the remnants of the old sealant must be removed, and the seams must be thoroughly cleaned of dust, dirt, and foreign matter.
It is not recommended to refill seams without clearing and blowing them.
5.1.29. To seal the seams of airfield pavements, hot and cold materials are used. To prepare them for use, you must use the instructions set out in the relevant technical specifications.
The basis of hot sealants is, as a rule, bitumen with fillers (crumb rubber, rubber, mineral powder, etc.).
Hot sealants are single component. Before use, they must be heated in special boilers to a temperature of 100 - 200 °C.
Cold sealants are usually based on cured liquid synthetic rubbers with fillers (chalk, kaolin, carbon black, etc.). These materials are two-component and are used cold with hardeners. They reach working condition in the seams after curing for several hours, depending on the ambient temperature.
The technical specifications for each airfield sealant indicate the road-climatic zone of its application.
Replacing a hot sealant with a cold one and vice versa is possible only after complete removal of traces of the replaced material from the seams of the cement concrete pavement, since there is no adhesion between the bitumen and synthetic rubber.
Seams should be filled in dry, cool weather.
5.1.30. The depth of filling the seams depends on the deformability of the material used and its adhesive properties. For hot-use sealants, as they are less deformable, the pouring depth should be in the range of 40-60 mm. For cold-applied sealants, the optimal ratio of the depth of filling joints to their width is 0.5-2.0. The filling depth should be limited by preliminary pressing into the seam a sealing cord (vilatherm, gernite, poronzol, etc.) with a diameter of 1.5-2 times the width of the seam.
For high-quality sealing of airfield pavement seams, their width should be 10-30 mm.
Filling the seam (sealing) should be done, as a rule, at a time with an underfill of 5-7 mm to the top of the coating for a material that does not shrink after curing, or the seam is filled flush with the surface of the coating if settlement of the sealing material is possible as a result of cooling or evaporation of the solvent contained in it.
Aerodrome sealants can be used to fill through cracks in the coating if their width is 5 mm or more. In this case, it is advisable to increase the fluidity of the sealing material by adding 10-20% organic solvent (gasoline, solvent, xylene, toluene).
It is also possible to use airfield sealants for repairing small chips; here they should be used as a binder together with inert fillers (crushed stone, sand).
5.1.31. Maintenance of the unpaved airfield in summer includes:
Assessing the suitability of the airfield for operation;
Ensuring the evenness, strength and density of soils on the working elements of the airfield;
Ensuring drainage from the surface of the airfield and taking measures to reduce the non-flying period;
Renewal and repair of markings;
Carrying out dust removal activities;
Removing foreign objects from the surface of the airfield;
Carrying out measures to strengthen the soils of the working part of the airfields and increase their erosion resistance;
Carrying out agrotechnical measures and improving the condition of the airfield turf.
5.1.32. The operational state of the soil airfield of the airfield is characterized by the strength of the soil of the airstrip, taxiways and stands, which depends on humidity, particle size distribution, degree of soil compaction and can vary within wide limits. Cohesive clay and loam soils are in a solid state in the dry season and have high strength. With increasing water content and increasing humidity, their cohesion decreases and their resistance to loads decreases. Such soils in a plastic state become unsuitable for aircraft operation.
Cohesionless soils, scaffolds and light sandy loams increase their resistance to loads with increasing humidity up to a certain limit, and then lose it as the full moisture capacity is reached. As the air temperature increases, the soil intensively dries out and gains strength in a short period of time.
In terms of granulometric composition, the best soils for airfields are sandy loam and light loam. They have sufficient strength when moistened and are suitable for quickly creating and maintaining turf cover.
5.1.33. The operation of aircraft at unpaved airfields has the following features:
During the muddy season, interruptions in flights are inevitable;
The possibility of taking off an aircraft during periods of waterlogging or muddy roads is determined by the conditions for lifting off the aircraft using its own engine power;
The ability to operate an aircraft depends on the type of chassis and wheel sizes, and the pressure in the tires.
5.1.34. For aircraft operation from unpaved runways, the permissible depth of wheel ruts on the unpaved surface should not exceed the maximum value that ensures the movement of the aircraft and the surface of the airfield is not subject to too rapid destruction and wear.
5.1.35. The degree of compliance of the aircraft characteristics with the operating conditions at unpaved airfields is determined by its ground maneuverability, which is understood as the ability of the aircraft to take off and move under the power of its own engines on waterlogged soil with acceleration sufficient to achieve take-off speed within the limits of the normalized technical requirements and the length of the runway. In this case, a rut should remain on the ground surface of such a depth that ensures both the safety of aircraft movement and the preservation of the turf cover, and leveling the cells will not require excessive costs and does not present difficulties.
5.1.36. The patency of the aircraft is characterized by the following defined parameters:
The minimum strength of the soil without turf cover, at which the aircraft can take off, taxi, take off (run), with the formation of the maximum permissible depth Hmax;
The operational strength of the soil is equal to or greater than when a track of operational depth Nexpl is formed, not exceeding Hmax and sufficient to preserve the turf cover. These parameters are set by the RLE.
5.1.37. As the strength of the soil decreases, deeper ruts form from the wheels of the aircraft, and the turf cover can be destroyed. In this case, the soil surface is difficult to level and repair, especially with subsequent drying and hardening of the soil.
5.1.38. Non-flying periods occur during thaw due to severe waterlogging upper layers soil and reducing its strength. Thaws are distinguished: long-term (autumn and spring) and short-term - summer. In the southern regions, thaw may continue throughout the winter period with short breaks, and in the regions Far North- during the summer.
5.1.39. Autumn thaw occurs due to frequent rains and a decrease in the average daily air temperature, when the soil becomes waterlogged and turns into a plastic or even fluid state.
5.1.40. Spring thaw begins immediately after the snow cover melts and the top layer of soil thaws. Additional soil moisture comes from spring rains. Conditions for aircraft operation begin from the moment the upper layers of soil dry out for aircraft of the 4th class to a depth of 15 - 20 cm, and for the 3rd class to a depth of 30 - 35 cm.
5.1.41. Summer thaw can occur during prolonged rains, when the amount of precipitation reaches 40 - 70 mm, especially when the rains coincide with a drop in temperature.
5.1.42. Improving the operational condition of unpaved airfields is ensured by:
Creating a good turf cover that promotes faster drying of the soil and prevents blowing and dusting of the soil;
Compacting soils to a certain density, reducing the seepage of moisture into the soil;
Drainage measures in areas with unfavorable hydrogeological conditions and terrain, as well as protection of the airfield territory from the influx of storm and melt water from adjacent areas;
5.1.43. The suitability of an unpaved airfield is assessed by comparing its characteristics and parameters with the flight manual requirements for a given aircraft type (see Sections 2.1 and 4.2 of this Manual).
5.1.44. The thaw period is considered non-flying when the soil strength of the airstrip becomes lower, for airfields without turf cover and below airfields with turf cover. It is recommended to approximately determine the duration of the non-flying period according to the schedule specified in Appendix 12.
5.1.45. Operation of aircraft on soils of minimal strength is permitted only on unpaved airfields without turf cover, since the resulting Hmax track destroys the turf cover. The only exceptions are those aircraft for which = .
5.1.46. Operating track depth Nexp. is acceptable. It depends on the size of the wheels of the main supports of the aircraft and is determined from the conditions for preserving the turf cover. In cases where Nexp. greater than or equal to Hmax, aircraft flights can be carried out on unpaved airfields with turf cover with minimal soil strength.
5.1.47. Ruts formed during aircraft flights from airfields with soil strength higher than operational strength can be corrected by rolling with pneumatic tires or metal rollers without destroying the turf cover.
Sealing ruts deeper than Nexp. on soils with a lower strength should be carried out immediately after the end of the flight.
5.1.48. The maintenance and repair of unpaved airfields without turf cover involves grading, correction of microrelief, filling of ruts and soil compaction by rolling in individual areas and elements of the airfield.
The microrelief is corrected by cutting, moving and redistributing minimum volumes of soil within 10 - 12 cm of the thickness of the surface layer to eliminate micro-irregularities, depressions, hills and ruts.
Compaction is carried out after leveling and correcting the microrelief using rollers on pneumatic tires or smooth metal rollers.
5.1.49. It is recommended to compact soils at their optimal moisture content, at which maximum density is achieved by means of compaction with minimum costs. Permissible deviations in soil moisture should not exceed 0.8-1.1 of its optimal moisture content.
If there is insufficient moisture, soil compaction will require the use of heavier rollers, and if there is excess moisture, it will take time to dry or use different rollers with a gradual transition from light to heavy.
5.1.50. It is recommended to take the approximate number of roller passes along one track according to the table. 5.1.
Table 5.1
(1) Rollers weighing 25-50 tons are used on soils with moisture content below optimal.
(2) The type of soil is determined based on laboratory analysis of its granulometric composition, and in the field - by an approximate method using the Krasyuk method (see Appendix 12, Table 3)
Note: The quality of compaction is controlled by determining the actual density of the soil according to GOST 5180 - 84, GOST 22733 - 77 and comparing it with the maximum density of a given type of soil, and the required density is assigned according to the project in fractions of the maximum density by achieving a certain compaction coefficient.
5.1.51. The main type of damage to the unpaved airstrip is rutting, which must be eliminated by surface leveling, sealing with loose soil, followed by compaction with smooth rollers.
It is recommended to eliminate ruts up to 6 cm deep by rolling them with smooth metal rollers weighing 3 - 5 tons at soil moisture close to optimal. It is recommended to fill up ruts and potholes up to 15 cm deep with local soil with preliminary loosening of the base to a depth of 5 cm. If the ruts and potholes are more than 15 cm deep, they are covered with ordinary loose soil, and then with a layer of 10-12 cm of vegetable soil.
With rut and pothole depths of up to 20 cm, soil compaction is carried out in one layer, and with a depth of more than 20 cm - in two layers.
It is not allowed to fill potholes and ruts with sand, crushed stone, slag or other bulk materials that differ from the soil of the airstrip.
5.1.52. At unpaved airfields without turf, significant soil blowing occurs from operating aircraft engines. Non-cohesive soils with particle sizes of 0.1 - 0.15 mm have the greatest erosion.
5.1.5.3. When choosing the most rational method of dust removal for specific conditions, it is recommended to take into account the period of use of the unpaved airfield, the duration of the dust removal effect, and the availability of appropriate mechanisms and materials for the work.
Reducing dust formation is achieved:
Reducing the degree of impact of aerodynamic and mechanical loads on the soil by installing various types of artificial surfaces or creating a turf cover;
Maintaining the structural and moisture regime of the soil, which would ensure its cohesion and the absence of structural and mechanical erosion;
By introducing various binders to strengthen the soil and stabilize it.
5.1.54. On the starting sections of the airstrip, which are most exposed to air currents and aircraft wheels, the most accessible method can be used - watering with water at a flow rate of 0.5 - 0.8 l/sq.m.
5.1.55. For dust removal, it is recommended to use the method of strengthening the soil with lime, which can be applied in the form of fluff or milk of lime in a ratio of 1:4 - 1:5 in an amount of 3-5% of the mass of the soil of the treated layer or use calcium chloride with a consumption of 1 kg/sq.m for every 10 cm of the thickness of the treated layer.
5.1.56. At unpaved airfields (heliports) the following materials and binders can be used to combat dust:
Hygroscopic salts;
Pulp and paper industry waste;
Various mineral and organic binders.
5.1.57. The most effective in combating soil dust are organic binding materials: bitumen, tar, oil, bitumen emulsions and oil-bitumen binders. The filling rate for organic binders is approximately: for crude oil and tar 3 l/sq.m, bitumen emulsions 2 - 3 kg/sq.m, diluted bitumen paste 6 - 8 l/sq.m, liquefied bitumen 3 l/sq.m, oil-bitumen binder 3 - 4.5% of the mass of dry sandy loam and loamy soil.
5.1.58. The technology of work when processing soils for dust removal includes the following operations:
Loosening, leveling and leveling the site;
Preparation and pouring (application) of binder onto the treated area;
Compacting the treated soil layer, if necessary.
The leveling and leveling of the cultivated area is carried out by motor graders, and the leveled area should not have slopes of more than 20% and unevenness more than 6 cm in depth.
Organic binders are poured, as a rule, using asphalt distributors, and bitumen emulsions are poured using mounted sprinklers evenly over the entire treated area. The impregnation layer must be at least 25 - 30 mm, and where it is less than the specified thickness, the treatment must be repeated.
5.1.59. For dust removal of sandy, sandy loam and loamy soils of airfields (heliports) and landing sites, it can be widely used (especially in the regions of the Far North and Far East) effective method dust removal with oil-bitumen binder, including bitumen, used oil from aircraft and automotive engines and a diluent in a ratio of 1:1:1. The duration of its dust removal effect is at least two years. For these purposes, medium-thickening and slow-thickening bitumen or others brought to the viscosity of liquid bitumen are used.
Any used oils or their mixtures with a specific gravity of 0.8-0.95 g/sq.cm and viscosity can be used as waste aviation oils 
without mechanical impurities larger than 1 mm.
The diluent can be kerosene, diesel fuel and others.
5.1.60. The working composition of the oil-bitumen binder is prepared as follows: liquid bitumen is pumped into the asphalt distributor tank up to 1/3 of its volume. After this, used oils are supplied in the same quantity. The mixture is mixed with an asphalt distributor pump, then a thinner is added in such an amount that it reaches a viscosity of 30 - 50c, and a binder with a lower viscosity value is used in the future when processing sandy loam, and with a higher viscosity value - loamy soils.
5.1.61. To ensure the penetration of oil-bitumen binder into the soil and uniform distribution, it is recommended to grind the surface layer, especially loamy soils, to a depth of at least 10 cm with a road milling machine in 1 - 2 passes or with disc or tooth harrows in 5 - 6 passes along one track.
After the binder is spilled, the treated soil is mixed in 1 pass with a road milling machine or in 2 - 3 passes with toothed or disc harrows. Next, the treated soil layer is compacted to a value of 0.8 - 0.95 from the standard compaction, depending on the element of the airfield, with 6-8 passes of pneumatic rollers, followed by compaction with smooth rollers with 3 - 4 passes along one track.
When treating non-cohesive soils using the impregnation method, the thickness of the treated layer must be at least 5 cm.
5.1.62. The bearing capacity of unpaved airfields increases by an average of 4 - 5 kgf/sq.cm when creating and maintaining a turf cover.
5.1.63. The sod must meet the following requirements:
Have a dense grass stand and a dense plexus of rhizomes to a depth of at least 12 - 18 cm;
Possess cohesion, elasticity and abrasion resistance;
Have a grass stand height of no more than 30 cm, and after mowing no less than 8 cm.
The quality of the turf cover is determined by the number of shoots of turf-forming grasses per unit area and the maximum rut depth at which it is destroyed, in accordance with the data in Table. 5.2.
Table 5.2.
5.1.64 . Turf care consists of the following work:
Combing the grass and leveling small irregularities;
Rolling the turf cover;
Fertilizing grasses with mineral fertilizers;
Artificial watering of grass vegetation;
Mowing grass.
5.1.65. Combing of the turf cover is carried out in two passes along one track using light toothed harrows or mechanical rakes.
5.1.66. It is recommended to roll the turf cover in early spring. It is carried out with 2 - 4 passes of 5-ton rollers on sandy loam soils and 10-ton rollers on loamy soils with a humidity of 2 - 3% more than optimal. Before the onset of frost, it is recommended to roll the surface with smooth rollers to give greater strength to the soil and eliminate rutting, which, when frozen, will make it impossible to operate the aircraft.
5.1.67. It is recommended to mow the grass at least twice a year. The first mowing is done when the plants reach a height of 30 cm, the second - in the fall before the onset of frost. The height of the grass when mowing should be 8 - 10 cm.
5.1.68. In the dry season, as well as in arid areas, artificial watering is recommended to enhance the growth of grasses. An irrigation rate of at least 200 cubic meters/ha is recommended.
5.1.69. A turf cover with thinned grass should be repaired depending on the degree of thinning: highly thinned - with a grass stand containing less than 15% of valuable grasses, moderately thinned - from 15 to 35% and slightly thinned - more than 35% of valuable grasses are present.
5.1.70. In areas with heavily and moderately thinned grass, it is recommended to carry out the following work: applying fertilizers, loosening the soil with disk cultivators or soil cutters to a depth of 3 - 5 cm; scattering the seeds of grasses most adapted to natural conditions airfield with their sealing with zig-zag harrows 2-3 times along one track and subsequent rolling with 3-ton rollers.
In slightly sparse areas, it is enough to only fertilize the plants with fertilizers.
5.1.71. It is recommended to sod ruts and potholes by sowing grass seeds or by replanting pre-harvested sod.
Sowing is carried out with seeds of the same grass mixture that grows on the airfield of the airfield with watering at a rate of at least 20 l/sq.m. Fertilizers are applied to the turf transplant areas, then it is tightly laid and rolled with 3-5 ton rollers. It is recommended to allow the use of areas of the airfield with transplanted turf after its complete establishment.
The best turf for replanting is considered to be turf made from grasses: red fescue, meadow grass, etc.
5.1.72. If the grass stand dies, it is recommended to loosen the soil in these places, apply mineral fertilizers and sow with a grass mixture. If upper layer soil is heavily impregnated with fuels and lubricants, it should be replaced to a depth of 20 - 30 cm with a new one, sowed or covered with turf.
5.1.73. Repair of unpaved airfields is recommended to be carried out taking into account the provisions of the “Guide to the organization and technology of repair of airfields without interruption of flight operation”.
5.1.74. To preserve the turf cover, one of the main measures is the uniform operation of the airfield with a postponement of the start as the turf cover wears out at intervals of 5 - 15 days.
5.1.75. Maintenance of drainage and drainage systems. Drainage and drainage systems (WDS, Fig. 5.1) should be kept in good condition.
Rice. 5.1. General view of the location of drainage systems at airfields:
1 - runway; 2. - RD;.3 - tray; 4 - rainwater inlet; 5 - edge drains; 6 - collector; 7 - inspection well; 8 - tall well; 9 - main collector; 10 - mouth (head); 11 - open drainage ditch; 12 - axis of the soil tray: 13 - selective drainage of soil areas; 14 - desiccant; 15 - collector: 16 - upland ditch
Inspection, drainage and water intake wells of the water supply system must be permanently covered with lids. Wells should only be opened when inspecting and repairing the water supply system.
Excavation work in the area where the VDS elements are located should be carried out only for special projects.
In spring, rainwater inlets and drainage wells should be freed from covers and shields.
After passing the drains, an extraordinary inspection of the entire water supply system should be carried out, and damaged elements should be repaired and restored.
Trays, ditches, wells, headers of collectors, bypasses should be cleared of sediment.
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MINISTRY OF CIVIL AVIATION
State Design, Survey and Research Institute
AEROPROJECT
Instructions for the responsible person at the international airport
on operational maintenance and repair of airfields
Moscow 1981
“Instructions for the responsible person of the international airport on the operational maintenance and repair of airfields” was developed at the State Pedagogical Institute and Research Institute of Civil Aviation Aeroproekt engineer. A.A. Serdyuchenko and Ph.D. those. Sciences M.S. Sardarov.
1. GENERAL PROVISIONS
1.1. “Instructions for the responsible person of an international airport on the operational maintenance and repair of airfields” is intended for class E airfields and landing sites.
1.2. The instructions were developed in accordance with the requirements of the "Manual on Aerodrome Service in civil aviation USSR", "Manuals for flight operations in civil aviation of the USSR" and "Manuals for the organization and technology of repair of airfields without interruption in flight operation".
1.3. The instruction establishes the main responsibilities of the responsible person and determines the procedure for maintaining and repairing airfields.
2. BASIC TERMS AND DEFINITIONS OF AERODROMES
An airfield (hydroaerodrome) is a specially prepared land area (water with adjacent coastal territory) that has a complex of structures and equipment that provides take-offs, landings, taxiing of aircraft, as well as their maintenance and storage.
Permanent airfield - an airfield intended for regular flights aircraft and having a certificate of registration.
Temporary aerodrome is an aerodrome prepared for flights for a limited period of time and does not have a registration certificate, but is subject to registration.
A side safety strip (SSB) is a specially prepared section of the airfield runway adjacent to the side boundary of the runway and is intended to increase safety during possible rollouts of aircraft during takeoff and landing.
End safety strip (ESL) is a specially prepared section of the airstrip adjacent to the end of the runway and designed to increase safety during possible rollouts of aircraft during takeoff and landing.
Runway (runway) - part of the airfield runway, specially prepared and equipped for take-off and landing of aircraft; Runways are divided into: artificial pavement runways (RWPP) and unpaved runways (GWPP).
The airfield is a part of the airfield on which flight strips, taxiways, aprons, parking areas and special-purpose areas are located.
Airstrip is a section of the airfield airfield intended for take-off and landing of aircraft and includes the runway, airfield and checkpoint.
3. RESPONSIBILITIES OF THE PERSON RESPONSIBLE
3.1. The main responsibility of the responsible person at an international airport is to maintain the airfield in constant operational readiness, ensuring the safe and regular operation of aircraft flights and the organization of their movement on the airfield.
3.2. The responsible person is obliged:
Carry out operational maintenance, repair and equipment of the airfield with markings in accordance with current requirements;
Develop and implement measures aimed at reducing delays and cancellations of aircraft flights due to airfield conditions;
Make decisions on termination, resumption or restriction of flights depending on the condition of the airfield;
Inspect the airfield before the opening of flights, after repair and maintenance work, changes in the condition of the airfield and precipitation. Record the inspection results daily, as well as when the condition of the airfield changes, in a special Log ();
Systematically monitor the technical condition of the airfield and take measures to eliminate identified defects before the start of flights;
Check the flatness of the surface of the unpaved runway and determine the strength of the soil or compacted snow;
Take part in the development of plans for capital and current repairs of the airfield;
Timely organize and ensure the implementation of work on current and major repairs of the airfield;
Introduce progressive methods for repairing airfield pavements and other airfield structures;
Carry out technical supervision over compliance with the requirements of regulatory documents for the repair of airfields;
Be guided by safety requirements when carrying out work on the maintenance and repair of the airfield;
Ensure careful storage correct use and economical use of material resources allocated for airfield repairs;
Ensure standard service life of structures and equipment with minimal maintenance and repair costs;
Be guided by the instructions of the “Regulations on carrying out scheduled preventative repairs of airfield structures of civil aviation airfields” when repairing airfield structures of airfields;
Ensure the availability and storage of materials, equipment and mechanisms for the maintenance and repair of the airfield.
Cleaning artificial surfaces from dirt, dust, debris and other foreign objects;
Updating the markings of coatings and portable markings;
Checking the condition of the surface of coatings, reinforced interface areas and adjacent soil areas of the airfield, recording changes and defects in artificial surfaces;
Maintaining the levelness of the soil part of the airfield and the established height of the grass stand;
Sealing of seams.
4.2. Cleaning of coatings from dirt, debris, dust and other objects should be done using plow-brush machines.
After the end of the spring thaw, the coating must be washed, the water consumption is 1 l/m2. In the dry season of the year in summer, dust from the coating is washed off with water at a consumption rate of 0.3 l/m2.
4.3. Markings on artificial surfaces must be updated as the paint material fades and wears out (two to three times a year).
Portable markings must be repaired as the structure wears out and their painting must be renewed at least twice a year.
4.4. In the fall, before frost sets in, artificial surfaces must be repaired to prevent water from entering the base through cracks, and the unpaved part of the airfield must be graded.
Unpaved airfields
4.5. The operational maintenance of unpaved airfields is characterized by the strength of the airfield soil and its evenness.
Under the strength of the soil σ refers to the ability of the soil to withstand the load from the wheels of the aircraft when the permissible rut depth is formed.
4.6. The aircraft's ground capability is characterized by:
Minimum soil strength σ min, at which the aircraft can move off under the power of its own engines, gain speed sufficient for takeoff while ensuring stability during the take-off run, and taxi, forming a rut of the maximum permissible depth;
Operational strength of the soil σ exp., in which a rut is formed that does not destroy the turf cover of the airfield.
4.7. Soil strength value σ and rut depths N for aircraft are given in the table.
|
Aircraft type and weight, t |
, KPa (kgf/cm 2) |
Hmax, cm |
σ exp., kPa (kgf/cm 2) |
|
|
M-15 xx (5.75) |
294,3-490,5 (3,6-5,0) |
294,3-490,5 (3,0-5,0) |
X - Normal tire pressure is 294.3 kPa (3 kgf/cm2).
xx - Reduced tire pressure - 196.2 kPa (2 kgf/cm2).
For helicopters of all types, the soil strength must be at least 294.3 kPa (3 kgf/cm2).
4.8. The strength of the soil is checked before the start of flights, in spring and autumn during the rainy season in the summer, after repairs and in each case when the condition of the soil changes.
The strength of the soil is determined by the U-1 striker. The procedure for using U-1 strikers and graphics for determining soil strength are given in.
4.9. Due to severe waterlogging (in spring, autumn and during heavy rains in summer), the strength of the soil sharply decreases and the operation of aircraft becomes impossible. This period is called thaw or non-flying period.
4.10. Reducing the non-flying period is achieved:
Ensuring drainage and protection of the airstrip from the influx of atmospheric and melt water from adjacent areas;
Improving the quality of planning, increasing the degree of soil compaction of the airfield;
Reducing the take-off weight of the aircraft;
Installation of simplified coatings;
Creating a durable turf cover;
Timely clearing of snow from the airstrip in the pre-spring period.
Combing the grass and leveling uneven areas;
Rolling the turf cover;
Mowing grass.
4.12. Combing of the turf cover is carried out in the spring, after the top layer of soil has dried, in order to remove dried plants and improve soil aeration. Combing is performed twice with light zig-zag harrows.
4.13. To increase the strength of the soil and enhance the tillering of grasses, as well as to eliminate clumps and hummocks, a turf cover is rolled down. Rolling should be done with rollers when soil moisture is 2-3% higher than optimal. To enhance the growth of grasses in the dry season and especially in arid areas, it is recommended to carry out artificial watering (in the morning or evening).
4.14. The grass stand is mowed when it reaches a height of 30 cm. The last mowing to a grass stand height of 8 cm is carried out in the fall, before the onset of frost.
At airfields where there is a large concentration of birds, the grass should be mowed to a height of 20-25 cm.
4.15. To maintain the turf cover in constant operational readiness, it is necessary to eliminate ruts up to 6 cm deep immediately after the cessation of flights, by rolling with three- to five-ton rollers.
4.16. Sodding of ruts, potholes and areas with sparse grass is done by sowing grass or by replanting sod. For sowing, seeds are selected from three to seven herbs most suitable for the given area. The grass mixture should include turf-forming grasses from the cereal and legume families.
In places of transplantation, the sod is tightly laid and rolled. Places for sowing and transplanting turf are fertilized and watered.
4.17. To preserve the turf cover, it is necessary to carry out uniform operation of the airfield, for which it is necessary to fly aircraft from one start for no more than one to two weeks. After specified period the start must be moved to another place.
Surface leveling and compaction;
Sealing ruts and uneven areas;
Fight against dust.
4.19. The leveling and compaction of the airstrip surface should be carried out in early spring and autumn before the onset of negative temperatures. Leveling work must be carried out in order to give the surface of the airfield a levelness that meets the safety requirements of aircraft and slopes that ensure the drainage of atmospheric and flood waters.
At airfields whose soils have rocky inclusions (crushed stone, gravel), leveling work must be carried out systematically, with the surface rolling using smooth rollers.
4.20. The sealing of ruts up to 6 cm and unevenness is carried out by cutting off the bumps and filling the depressions, followed by rolling them with three- to five-ton rollers.
Ruts more than 6 cm deep are filled with ordinary soil and then compacted. Filling ruts with sand, slag or other material different from the soil of the airstrip is not allowed.
4.21. The main measures to combat dust pollution are:
Watering is an ineffective method and requires a large consumption of water, therefore, as a rule, only the starting sections of the airstrip are watered;
Strengthening soils with inorganic binders - lime, which is added in the form of fluff or lime milk in a ratio of 1:5 in an amount of 5% of the weight of the treated layer;
Strengthening soils with organic binders - bitumen, bitumen emulsions, tars and oil production waste. The spill rate is 1-1.5 kg/m2.
Airfield markings
Marking of airfields with artificial surfaces
4.22. The longitudinal axis of the runway and the threshold are applied to the runway surfaces with white markings (Fig. 1). The longitudinal axis is marked with dotted stripes of the same length, located at an equal distance from each other with a step of 5 m and a screen of 0.3 m. The first dotted line is applied at a distance of 12 m from the threshold marking. The threshold is marked with a transverse solid line 1.2 m wide, which is drawn at a distance of 6 m from the end and 3 m from the edge of the runway.
Rice. 1. runway marking:
1 - threshold; 2 - runway axis; 3 - RD axis
Taxiways are marked along the longitudinal axis with dotted lines with a pitch of 1 m and a width of 0.15 m.
4.23. Landing areas for helicopters are marked according to Fig. 2. A landing restriction sign for helicopter landings, boundary markers and starting lines are placed on artificial surfaces.
4.24. For marking artificial surfaces, enamel grade EP-5155 (Tu 6-10-1085-75) should be used. Before applying enamel, the surface of the coating must be cleaned of dust, dirt and oil stains. Traces of old markings are not removed.
Rice. 2. Helicopter pad markings:
1 - landing site sign; 2 - border sign; 3 - starting line
Equipment of airfields with portable markings
4.25. International flight airfields in accordance with Fig. 3 are equipped with entrance shields, landing marker T, boundary markers and wind direction indicators. Red flags can be used as marking signs in the summer, and bunches of coniferous trees in the winter.
4.26. Entrance boards (see Fig. 3) are installed on the end line of the airstrip or runway 5 m from its side border and mark the beginning and end of the airstrip or runway. The shields are painted in alternating stripes 0.4 m wide of white and black. The opposite side of the shields is painted red and white. The entrance shield is a triangular frame prism 2.8 m long and 0.9 m high. The sign is made of a wooden frame and covered with plywood or boards.
Rice. 3. Equipping the airfield runway with markings:
1 - entrance shield; 2 - landing mark T; 3 - border sign
4.27. The landing sign T (see Fig. 3) is laid out on the side safety strip 3 m from the edge of the runway and 50 m from its beginning. The T landing sign set consists of six panels: three red and three white. The dimensions of the panel are 6×1 m.
4.28. Boundary signs (see Fig. 3) are installed at a distance of 100-50 m from each other (depending on the length of the airstrip) and 1 m along the side boundaries of the airstrip.
4.29. On taxiways and stations, boundary signs are installed at a distance of 20 m from each other and 1 m from the side boundaries of taxiways and stations. The places where an aircraft taxis from the runway to the taxiway and from the taxiway to the terminal and apron are indicated by double boundary signs, which are installed on each side of the taxiway with an interval of 2 m from one another.
Border markers are painted with alternating stripes of red and white. Signs are made from plywood or boards mounted on a frame, or from tin without a frame and have the shape of a cone.
Rice. 4. Windsock
4.30. The windsock (Fig. 4) has the shape of a truncated cone and must be installed in such a way that it can rotate freely through 360°. Windsock dimensions: diameter of the lower base 0.5 m, upper base - 0.2 m, height 1 m. The choice of windsock color depends on the background of the area, it can be white or orange-red, a combination of two alternating colors is possible: white with orange-red red or white and black. Flags measuring 1.0×0.76 m in white or orange-red colors can be used as a wind direction indicator.
Airfields with artificial surfaces
5.1. When preparing an airfield for winter operation, you must:
Carry out leveling work, eliminate security guards, roll the surface of the airfield, mow the grass;
Perform routine repairs of artificial surfaces;
Restore the labeling of artificial surfaces;
Update portable markings;
Repair airfield vehicles and trailed mechanisms and prepare them for work in winter conditions;
Draw up a plan for the maintenance of the airfield winter period;
Prepare the necessary construction materials for repairing the airfield in winter, as well as dry sand to eliminate slippery conditions.
5.2. In areas with unstable negative air temperatures and frequent thaws, international airfields with runways should be maintained by snow removal, and in areas with stable negative air temperatures - by snow compaction.
5.3. To ensure that the airfield is ready for flights in winter, the following requirements must be met:
The runway, taxiway, stopover and apron should be completely cleared of snow and ice;
Clear the KPB of snow by half their length on each side;
Clear the BBP of snow to a width of 25 m on each side, and then arrange junctions of snow with a slope of 1/10;
The shoulders of taxiways, stations and aprons should be cleared of snow to a width of 10 m with a snow interface device with a slope of 1/10.
5.4. On the cleared PPB, BPB and sides of taxiways, MS and apron, a layer of compacted snow up to 8 cm thick and a layer of freshly fallen snow up to 10 cm are allowed.
5.5. Clearing the runway from snow should be carried out by patrolling with snow plows and brushes from the beginning of the snowfall and end an hour after it stops for the entire width of the runway. The operation of snow plows and brushes must be organized in such a way that they move sequentially, one after the other, from the axis of the runway to the sides, overlapping the previous track by 0.3-0.4 m. The minimum distance between moving vehicles must be at least 30-35 m Snow collected in shafts is immediately removed by rotary snow blowers beyond the boundaries of the cleared strips or leveled on the adjacent unpaved part of the airfield.
5.6. Aircraft take-off and landing are allowed if there is dry, freshly fallen snow on the runway with a thickness of no more than 5 cm, slush of 12 mm and water of 10 mm.
5.7. The runway under a layer of compacted snow is prepared and maintained to the length of the runway, increased on each side by half the CPB, and a width of 60 m, consisting of the width of the runway and two equal parts of the MB. The thickness of the compacted snow layer should be within 6-8 cm. Connections made of uncompacted snow are arranged with a slope of 1/10. Requirements for the strength of compacted snow cover on the runway for various types aircraft are taken the same as for unpaved airfields maintained by snow compaction.
5.8. When the runway is maintained under a layer of compacted snow, the first layer is created by compacting the snow with pneumatic rubber or rubber-concrete rollers, followed by smoothing with trowels. Subsequent snow compaction on the runway is carried out using the same technology as on the main runway. After creating a layer of compacted snow 6-8 cm thick, further maintenance of the runway is carried out by clearing snow.
5.9. As it is used, the snow on the runway is destroyed and blown away under the influence of wheels and air jets from aircraft engines. To restore the layer of compacted snow in such areas, it is necessary to compact the snow instead of clearing it.
5.10. Two to three weeks before the onset of positive air temperatures, the layer of compacted snow must be removed from the runway surfaces. Compacted snow is cut in layers 1-2 cm thick using a motor grader. The snow cut and collected into a shaft is removed outside the runway.
Clearing the runway from compacted snow continues until the surface is completely cleared.
Unpaved airfields
5.12. Operation of aircraft on unpaved airfields in winter is permitted under steady conditions. negative temperatures air and freezing of the upper layers of soil for An-2, M-15 and L-410 aircraft to a depth of 5-6 cm. At a shallower freezing depth, it is necessary to determine the strength of the soil (see) under the layer of frozen soil. If the strength of the soil meets the requirements for a particular type of aircraft, then its operation is permitted even at a lower depth of soil freezing.
5.13. Unpaved airfields, regardless of climatic conditions and location, are maintained by snow compaction.
5.14. The operational state of a dirt airfield in winter is characterized by the strength of compacted snow. Each type of aircraft has its own operational and minimum permissible strength of compacted snow.
5.15. If the compacted snow cover is operationally strong, regular aircraft flights are permitted, but the rut depth from the aircraft wheels should not exceed 2 cm.
With a minimum permissible strength, one-time aircraft flights are permitted, and the depth of the ruts from the aircraft wheels should not exceed 6 cm.
5.16. The strength of compacted snow cover for An-2, M-15, L-410M aircraft is as follows:
For regular flights (operational strength) 392.4 kPa (4 kgf/cm 2);
For one-time flights (minimum strength) 294.3 kPa (3 kgf/cm2).
For helicopters of all types, the strength of the compacted snow cover must be at least 294.3 kPa (3 kgf/cm2).
5.17. The strength of the compacted snow cover is determined before the start of flights, after each snow compaction and when the temperature rises. The determination of the strength of compacted snow cover is given in.
5.18. Compaction of freshly fallen snow is carried out when the snow thickness is 5 cm and continues until the snowfall stops. To increase the strength of compacted snow, rolling of the runway should be carried out even when the air temperature rises, regardless of snowfall.
5.19. The snow is compacted first with trowels, then with rollers, followed by smoothing with trowels. To compact snow, trowels designed by NIAS, GVF, wide-grip with two inclined bottoms, which are manufactured by the airport, and pneumo-rubber, wooden, metal, rubber-concrete rollers weighing 10-15 tons are used.
5.20. Behind the side boundaries of the runway, gentle slopes with a slope of no more than 1/10 should be arranged, which must be graded.
5.21. Preparation of airfields for the operation of the An-2 aircraft on a ski chassis consists of eliminating irregularities (bumps, bumps, ruts) exceeding 25 cm, which is achieved with a one-time pass of a light smoothing iron.
5.22. Operation of aircraft with wheeled landing gear may be permitted if there is freshly fallen snow up to 5 cm thick on the surface.
5.23. Ruts, potholes, furrows and snow banks must be systematically leveled with snowdrift cutters and smoothers and compacted with rollers. Leveling ruts with a depth of up to 3 cm should be done by passing smoothers in the longitudinal direction; ruts more than 3 cm are leveled first by transverse and then longitudinal passes.
5.24. When the top layer of compacted snow cover icing, the ice crust should be destroyed with spike or ribbed rollers and then compacted with trowels and rollers.
5.25. To extend the service life of the airfield, it is necessary in the spring before the snow melts to systematically compact the airstrip, gradually reducing the layer of compacted snow. Snow compaction should be done in the afternoon so that under the influence of night frosts the snow acquires the necessary strength.
5.26. Before intensive snow melting begins, it is recommended to clear the airstrip of snow. Snow storage must be done in low areas outside the airfield in order to prevent its flooding with melt water. To prevent melt water from entering the cleared airstrip, drainage ditches must be installed. Depending on the terrain, drainage ditches are made on the side of possible water flow. Drainage ditches are made with a single-blade plow.
6. REPAIR OF AIRFIELD ELEMENTS
General provisions
6.1. Repair of airfields is divided into routine and major. Current repairs include work to systematically and timely protect the airfield from premature wear by eliminating minor damage and malfunctions. Current repair work is carried out without stopping the operation of the airfield. The overhaul of the airfield includes work during which significant amounts of damaged and deformed surfaces are corrected.
6.2. The most typical deformations and destruction of airfield pavements are:
On artificial surfaces - cracks, waves and sagging, spalling ruts and potholes, subsidence and breaks, destruction of surface treatment;
On the ground - ruts, surface unevenness, decompaction and destruction of the surface layer of soil (dust formation), damage to the turf, death of the grass stand.
Asphalt concrete pavements
6.3. When repairing asphalt concrete pavements, cracks and potholes are sealed, waves and swells are eliminated, and the coating is restored in certain areas with a crumbled surface layer and in areas with subsidence and breaks.
6.4. Small hairline cracks are eliminated by rolling the coating with heavy rollers, as well as by pouring liquefied or hot bitumen BND 60/90 or BND 90/130 over this area, followed by sprinkling it with sand or mineral powders in an amount of 1 m 3 per 10,000 m 2 of the coating with rolling with hot road rollers irons or rollers.
Cracks up to 15 mm wide are cleaned of dust and dirt and blown out with compressed air. After cleaning or blowing, the crack is filled with a mixture of viscous bitumen BND 60/90 or BND 90/130 with mineral powder in a 1:1 ratio or RBV.
After cleaning, cracks wider than 15 mm are primed with liquefied bitumen and then filled with Izol mastic, RBV or asphalt concrete mixture. The surface of the repaired cracks should be sprinkled with sand or mineral powder and rubbed with a hot iron. The temperature of the material must be at least 150-170 °C. The material used to seal cracks must be elastic, waterproof with sufficiently high temperature resistance and have good adhesion to asphalt concrete. The most suitable for filling cracks are rubber-bitumen mastics "Izol", RBV-25, RBV-35, RBV-50.
6.5. Restoration of a coating with a chipped surface layer is carried out by surface treatment using bituminous materials and stone cuttings.
The procedure for surface treatment is as follows: the coating is first cleaned of dust and dirt using watering machines, then liquid medium-thickening bitumen SG-15/25, SG-25/40 or a 75% solution of viscous bitumen BND 60/90 in gasoline is poured using a asphalt distributor. with a flow rate of 0.8-1.5 l/m 2. Bitumen is poured cold or heated at a temperature of 30-60 °C. After the bitumen is spilled, hot (140-160 °C) stone seedings of 3-10 or 3-5 mm in size are scattered over it, pre-treated with bitumen BND 90/130 or BND 40/60 in the amount of 0.008-0.011 m 3 per 1 m 2 of coating . Stone castings must be made of igneous rocks with a compressive strength of at least 78,400 kPa (800 kgf/cm2). This is followed by rolling the stone castings immediately until they cool. If the seedings have cooled down before rolling, then rolling them does not provide high-quality surface treatment.
6.6. Filling areas with potholes includes the following work: outlining the damaged area, cutting down the covering to the depth of the pothole, but not less than 2-3 cm. The walls of the pothole must be vertical.
The area to be repaired is cleaned, primed with a thin layer of liquefied bitumen and a hot asphalt concrete mixture is laid. When the cutting depth is more than 5 cm, the asphalt concrete mixture is laid in two layers with layer-by-layer compaction.
Compaction of the laid mixture with small (0.2-1.0 m 2) potholes isolated from one another is carried out using a tamper weighing 15-25 kg or pre-heated manual metal rollers. The mixture is compacted with tampers from the edges to the middle. The joints between the new asphalt concrete and the old are smoothed with a hot metal iron. If the area of potholes to be filled is large, the asphalt concrete mixture is compacted with motor rollers, manual vibratory rollers or rectangular vibrators.
To fill potholes, use a fine-grained or sandy asphalt concrete mixture.
6.7. Waves and swells are eliminated by rolling the coating with heavy rollers in hot weather. Methods for eliminating waves and shifts in the coating depend on the size and nature of these deformations. If there are no breaks in the coating, these defects are eliminated by rolling from the edges to the middle, overlapping the traces of the passages of a roller weighing 10-15 tons by 20-25 cm. Waves, bumps and shifts that are large in area and height are cut off with motor graders or cut down to the entire thickness of the coating. After correcting the base, it is primed with liquid bitumen and an asphalt concrete mixture is laid, taking into account the settlement for compaction.
6.8. The mounds formed from plant germination are cut off with heated scrapers or cut down. Plant roots; must be removed and their germination site treated with herbicides.
6.9. Repair of areas with subsidence and breaks is carried out in the following sequence: cut down the asphalt concrete within the boundaries of the subsidence or break, dismantle the artificial base and check the underlying soil, which, depending on its condition, is strengthened with binding materials or replaced with another more stable one, then the artificial base is restored and laid new asphalt concrete surface. Breaks that occur as a result of obtaining underlying soils are repaired only after installing a new artificial foundation with a thermal insulating layer.
Lightweight coatings
6.10. Routine repair of lightweight pavements made of durable crushed stone materials of selected composition, treated with organic binding materials, is carried out in two ways: cold and hot.
In the first case, cold stone materials treated with bitumen, black crushed stone or black cuttings are used, prepared by mixing them with liquid or liquefied bitumen. Work using this method should be carried out in dry and warm weather at an air temperature of at least 5 °C. In the cold method, bitumen grades MG 70/130 are used; MG 130/200; SG 70/130 and SG 130/200.
In the second case, dry, clean crushed stone and bitumen are used, heated within 150-180 °C. Work using this method is carried out in dry weather at an air temperature not lower than + 10 ° C. In the hot method, bitumen grades BND 130/200 and BND 90/130 are used.
6.11. When repairing damaged areas of surface treatment using the hot method, work is performed in the following sequence:
Cleaning and drying the repaired area;
Lubrication of the surface of the repaired area covered with a thin layer of hot bitumen;
Scattering, leveling and compaction of the wedge;
Spilling bitumen heated within 150-180 °C over a wedge layer;
Scattering, leveling and compaction of stone fines. The consumption of bitumen grade BND 130/200 or BND 90/130 should not exceed 1.5 l/m2.
6.12. In the cold repair method, after cleaning and drying, the coating surface is lubricated with a thin layer of liquid bitumen of grades MG 70/130, MG 130/200 or SG 70/130, SG 130/200 heated to 60 °C with a consumption of 0.3-0.5 l /m2.
Then first lay a layer of black crushed stone of fractions 5-15 mm, which is leveled and compacted. Black stone chips are laid in an even layer on top of the black crushed stone and compacted.
6.13. Small hairline cracks, shallow smooth depressions or elevations in the coating can be eliminated by rolling the damaged areas with motor smooth rollers or rollers on pneumatic tires. The air temperature should not be lower than + 15 °C.
Small areas with a dense network of small cracks are repaired by pouring a thin layer of hot viscous bitumen with a scattering of coarse, clean and dry sand or stone chips up to 5 mm in size over it, followed by rolling.
Cracks up to 5 mm wide should be repaired by pouring hot bitumen mastic heated within 150-160 ° C, backfilling with coarse sand or stone castings and subsequent rolling.
Through cracks more than 5 mm wide are repaired by cutting out the coating along the crack on both sides to the depth of impregnation. The width of the cutting must be at least 10 cm. The walls of the cutting are treated with a thin layer of liquid bitumen and filled with black crushed stone in two layers. Crushed stone of fractions 26-40 mm is placed in the bottom layer and crushed stone of fractions 15-25 mm is separated. For the top layer, crushed stone of fractions 5-15 mm and black stone seedings of fractions 0-5 mm are used. Each layer of crushed stone must be carefully compacted with metal tampers.
6.14. Potholes and subsidence are repaired using hot or cold methods. In this case, the defective area is excavated to the entire depth of the pothole or subsidence. The cutting should be rectangular in shape with steep walls.
With the hot method, the bottom and walls of the cutting are lubricated with a thin layer of hot bitumen with a flow rate of no more than 0.6-0.8 l/m2. Then clean and dry crushed stone is placed in the cutting area.
When the cutting depth is 4-5 cm, crushed stone of a fraction of 25-40 mm is used, which is clinched with crushed stone of a fraction of 15-25 mm. After compacting the crushed stone layer, bitumen of grades BND 130/200 or BND 90/130 is poured over it, heated within 150-180 °C at a rate of no more than 4 l/m2. Crushed stone of 5-15 mm fractions is laid on hot bitumen, which is first compacted and then rolled with rollers.
When the cutting depth is less than 4 cm, crushed stone of 15-25 mm fractions is placed in the first layer, which is unlined with crushed stone of 5-15 mm fractions. After compacting the crushed stone layer, hot bitumen is poured with a flow rate of no more than 2.5 l/m 2, and then stone seedings of fractions of 0-5 mm are scattered over the bitumen and thoroughly compacted.
When repairing potholes and subsidences more than 4-5 cm deep, crushed stone of fractions no more than 0.8 from the cutting depth is placed in the first main layer. Bitumen is poured over it and crushed with a finer fraction of crushed stone. After the second bitumen spill, crushed stone of 15-25 mm fractions or a wedge of 5-15 mm fractions are scattered. Then a third spill is made and stone seedings of fractions of 0-5 mm are scattered. Total consumption bitumen should not be 0.8 l/kg (for a cutting depth of up to 6 cm) and 1.0 l/m2 (for a cutting depth of more than 6 cm) for each centimeter of the thickness of the repaired coating. Each layer of crushed stone must be carefully compacted with smooth metal rollers or rollers with pneumatic rubber tires. When repairing potholes small area compaction of the laid materials is carried out using manual tampers.
With the cold method of repairing potholes and subsidence, work to prepare the area to be repaired is carried out in the same way as with the hot method.
The sealing of cuttings up to 5 cm deep using the cold method is carried out as follows. First, the bottom and walls of the cutting are lubricated with a thin layer of liquid bitumen heated to 60 °C, then black crushed stone of fractions 15-25 mm is placed in it and compacted with tampers weighing 15-25 kg. A black wedge of fractions of 5-15 mm is laid on top of a layer of black crushed stone and the words are compacted. Black stone seedings of fractions of 0-5 mm are distributed over the layer of black wedge and compacted again.
To fill a pothole up to 5 cm deep, a pre-prepared mixture of various fractions of black stone materials or a mixture of cold asphalt concrete with crushed stone can also be used. In the first case, the following ratio of mixture components is used: black crushed stone fractions: 15-25 mm - 70-75%, black wedge fractions 5-15 mm and black stone cuttings - 25-30%.
A mixture of cold asphalt concrete and crushed stone is prepared from the ratio of two volumes of clean and dry crushed stone of a fraction of 15-25 mm and one volume of cold asphalt concrete.
The mixture prepared in advance is placed in a clearing in one layer, then compacted and backfilled: in the first case with a layer of stone fines of a fraction of 5-15 mm or black stone cuttings, in the second - with a layer of cold asphalt concrete and carefully rolled.
Potholes with a depth of more than 4-5 cm are sealed layer by layer with black crushed stone of fractions 25-40 mm, 15-25 mm and 5-15 mm or two layers of a mixture made up of the same fractions of black crushed stone, in a volume ratio of 2:1:1. Black grains of 0-5 mm fractions are scattered over the surface of the laid material and rolled.
Repair of areas where the coating has broken due to damage to the base is carried out in the following sequence:
The covering and base are cut down to the full thickness;
Remove all loosened material and the disturbed layer of underlying soil;
The layer of underlying soil and foundation is re-laid and thoroughly compacted;
Arrange the covering.
The cuttings must be sealed using the same materials and the same technology as those used to construct a new coating.
Transitional coatings
6.15. During the current repair of transitional type coatings (made of crushed stone and gravel materials, soils, gravel-sand and crushed stone-sand mixtures, strengthened with organic and inorganic binders), potholes, ruts, waves, bumps and other minor damage are eliminated, and the destroyed surface treatment layer is restored with a small amount of destruction.
When eliminating minor damage to coatings, pre-prepared mixtures of materials similar to those used in the coating are used.
6.16. Potholes, breaks, ruts, and subsidence in small areas are eliminated by patching. In this case, the area to be repaired is prepared in accordance with clause 6.16. of this Instruction. The edges and bottom of the pothole are lubricated with liquid bitumen or BND 90/130 bitumen heated to a temperature of 60 °C in an amount of 0.5-0.7 l/m. The pothole prepared in this way is filled with a repair mixture prepared in advance, taking into account its compaction coefficient, and thoroughly compacted by tamping or rolling.
During routine repairs of transitional type coatings (treated with organic binders), it is advisable to use asphalt heaters, which allow softening the coating material by heating and repairing deformed or damaged areas without removing the old coating material. The work is performed in the following technological sequence:
Cleaning the coating from dust and dirt with metal brushes;
Heating the area being repaired;
Loosening the heated material with the addition of the required amount of new material, similar to that used in the coating;
Mixing old material with new, leveling and compacting.
6.17. For compaction, pneumatic or electric rammers, vibrating hand rollers, as well as self-propelled rollers on pneumatic tires or motorized smooth metal rollers are used.
Repair of coatings made from soils and local materials treated with mineral binders is carried out using the technology given in paragraph. In this case, the walls and bottom are not coated with hot bitumen.
The elimination of potholes, waves, sagging, and dents in coatings made of crushed stone and gravel materials treated with organic binders is carried out similarly to the repair of lightweight coatings in accordance with the requirements of paragraphs. and this Instruction.
6.18. Routine repair of gravel and crushed stone surfaces consists of leveling their surface, eliminating individual holes, potholes, and subsidence.
The leveling of gravel and crushed stone surfaces, arranged using the method of selecting optimal mixtures, is carried out using a motor grader; it includes the following operations:
Moistening the coating to optimal humidity;
Profiling of coating;
Seal.
6.19. Moistening should be done immediately before profiling. Depending on the weather and humidity of the coating, the amount of water poured can be 6-12 l/m2.
Profiling of the surface of the coating is carried out using a motor grader in several passes over one area. For compaction, rollers with pneumatic tires weighing 10 tons or more are used. Compaction begins from the outermost sections of the coating and proceeds to the middle, covering the previous passes of the roller.
An external sign of the end of rolling is the absence of traces on the surface as the roller passes and the cessation of wave movement in front of it.
6.20. When leveling gravel and crushed stone surfaces with the addition of new material, first clean the surface of the coating from dirt and moisten it. Then the coating is loosened and profiled with a motor grader. A ready-made gravel or crushed stone mixture of optimal composition is delivered to the leveled surface and evenly distributed over the entire width of the coating, then thoroughly compacted with rollers on pneumatic tires or with metal rollers, first light (5-8 tons), and then heavy (10-15 tons and more) rollers using the technology specified in paragraph of this Instruction.
6.21. When repairing potholes or subsidence of gravel and crushed stone coatings, you must first clean the area being repaired from dust and dirt, then loosen the coating and remove the loosened material, after which the pothole is filled with new material, similar in composition to the material of the old coating. Loosened material after sifting can be used to fill potholes, pits and subsidence.
6.22. For better compaction and connection with the coating, gravel and crushed stone material must be watered. The moisture content of the material during laying and compaction should be close to optimal.
For a large volume of repair work, compaction is carried out with rollers on pneumatic tires or with metal rollers weighing 10-15 tons, and for a small volume, with manual rammers weighing 15-25 kg.
Unpaved airfields
6.23. Repair of unpaved airfields includes:
Correction of microrelief, elimination of ruts, leveling and rolling of the soil surface and elimination of dust on them;
Repair of turf cover with elimination of ruts, potholes and saucers on it.
Irregularities on the ground surface are eliminated with motor graders, and compaction is carried out with rollers.
6.24. Soil compaction should be carried out at optimal moisture content. The runway compaction coefficient must be at least 0.95.
The strength of soils can be increased by compaction, improvement of their granulometric composition, bringing it to optimal by adding missing fractions, and treating soils with various binders.
6.25. Treatment of soils with binders must be carried out in accordance with the requirements of the "Instructions for the use of soils strengthened with binders for the construction of bases and coatings" highways and airfields ( SN-25-74), as well as the “Guidelines for strengthening soils at civil aviation airfields”.
6.26. Dust on unpaved runways is eliminated by watering with water at a flow rate of 0.6-0.8 l/m2, as well as by treating them with organic binders. Work on dust removal of soils should be carried out in accordance with the “Instructions for dust removal of unpaved airfields and helipads” (VSN 38-76/MGA).
6.27. Repair of unpaved runways with turf cover involves restoring the density of the grass stand. The density of the grass stand is restored by sowing grass seeds (highly and moderately thinned areas) and regularly feeding the grass with fertilizers (weakly thinned areas).
To speed up the repair of turf on unpaved airfields, it is advisable to use replanting of living turf in the form of its layers, which are harvested in areas outside the airfield. Before preparing layers of turf for replanting, the grass must be mowed.
The procedure for repairing areas with thinned grass and its unsatisfactory composition depends on the degree of thinning. After applying fertilizer, an area with highly thinned grass stand (less than 15% of valuable grasses) is loosened thoroughly with disc harrows (cultivators) or soil cutters to a depth of 5 cm and sown with grass seeds, which are covered with zig-zag harrows in two or three passes one at a time. followed by rolling with three-ton rollers.
Repair of areas with moderately thinned grass (15-35% of valuable grasses) is carried out similarly to highly thinned areas, but without preliminary loosening of the soil.
In weakly thinned areas (more than 35% of valuable grasses), the grass should be fertilized regularly with fertilizers.
Repaired areas should not be used for 2-3 months. until the grass is restored and a strong turf is created.
When overseeding and restoring old turf, two conditions must be met: temporary weakening of the viability of old vegetative regenerating grasses and maximum improvement of the water-air-food regime of the environment for the rooting of sown grasses. The first is achieved by harrowing or disking the turf until it is black, and the second is partially achieved by the same treatment and must be partially supplemented by applying fertilizers and, if necessary, irrigating or draining the soil. Fertilizers in such cases are applied in full quantities.
Oversowing of seeds should be done immediately after processing the turf. Belated reseeding due to the rapid restoration of the vital activity of old grasses may be ineffective.
Any stains that form on the coating must be eliminated immediately after flights:
Ruts up to 6 cm deep are eliminated by rolling with two- to five-ton metal rollers at soil moisture close to optimal;
Ruts, potholes and saucers 6-15 cm deep are covered with local plant soil. Before filling the soil, the base must be loosened to a depth of 5 cm;
Ruts, potholes and saucers with a depth of more than 15 cm are first filled with ordinary soil available at the airfield and no different from the soil of the airfield.
In this case, the thickness of the layer of plant soil should be at least 10-12 cm.
With a rut depth of up to 20 cm, the sent soil is compacted in one layer, with a depth of more than 20 cm - in two layers. For compaction, rollers with pneumatic tires or metal rollers with smooth rollers weighing 5-8 tons are used.
Sodding of ruts and potholes can be done either by sowing grass seeds or by replanting the turf.
6.28. Replanting the turf should be done in prepared areas. If the area is small, the area should have the shape of a rectangular trough with vertical walls 1-2 cm deep less than the height of the turf layers so that after rolling or compacting in small areas, the surface of the turf is flush with the surface of adjacent areas.
The base of the soil in places where the turf (layers) are transplanted must be loosened and fertilized.
The turf is tightly laid on the prepared base and rolled with three-ton rollers. The laid turf should be immediately watered with water at the rate of 20 l/m2, and then, in the absence of rain and in dry weather, it should be watered periodically. It is advisable to carry out work on transplanting turf during the humid period of summer.
The coating repaired by replanting the turf can be used immediately after the completion of the turf work. However, good engraftment of the turf layers to the base and to each other is achieved by maintaining a certain period of time, which, depending on climatic conditions, time of transplantation, quality of turf and production of work is 0.5-1.5 months.
6.29. In areas where the turf cover has died as a result of soil impregnation with oil, gasoline and other substances, the soil should be loosened, mineral fertilizers should be added to it and sowed with grass mixture. If the soil is heavily and deeply saturated, then the top layer 20-30 cm thick should be replaced with new soil, sown with grass mixture or covered with turf.
Winter period
2.02.80
10 o'clock
Summer strip under compacted snow with a strength of 5 kgf/cm 2. RD, MS under compacted snow with a strength of 7 kgf/cm 2. At KPB, BPB - compacted snow 8 cm thick.
A.K. Volkov
Summer period
10.05.80
22 h
The summer strip is rolled away. Soil strength 5 kgf/cm 2
The airfield meets the requirements of the US Civil Aviation Authority
A.K. Volkov
Appendix 2
Determination of conditional soil strength
The conditional strength of the soil can be determined by the U-1 impactor (Fig. 1), which consists of a tip 1 with divisions marked on it every 1 cm, a weight 2 weighing 2.5 kg for driving the tip into the ground and a guide rod 3 for moving along it weights.
Rice. 1. Diagram of the U-1 striker
To measure the strength of the soil, the U-1 striker is placed vertically with the tip on the ground, the weight is raised along the guide rod to a height of 50 cm and lowered. When falling, the weight drives the tip rod into the ground to a depth of 10 and 30 cm. The number of blows of the weight is counted when the tip is immersed in the ground by 10 cm, with an increasing total up to 30 cm.
Then the arithmetic average values are established from the measurements taken separately for immersion at 10 and 30 cm. The strength of the soil at a depth of 10 and 30 cm for the average number of impacts is shown in Fig. 2. Soil strength is determined by the formula
Where σ - soil strength at the measurement site, kPa (kgf/cm2);
σ 10.30- soil strength to a depth of 10 and 30 cm.
Rice. 2. Determination of soil strength by the number of impacts with a U-1 striker to a depth of 10 cm (A) and 30 cm (B)
1 - sandy, sandy-silty, sandy loam and fine sandy loam soils; 2 - silty, loamy and heavy loamy soils; 3 - chernozems, chestnut and other saline soils
The soil strength of the airstrip is determined as the arithmetic mean value of the soil strengths divided by their quantity.
Appendix 3
Determination of the strength of compacted snow cover
To determine the strength of compacted snow cover, the NIAS hardness tester is used.
Hardness tester NIAS
The NIAS hardness tester (see figure) consists of a cone 1, a platform 2 for a person’s foot, a vertical stand 3 and a vertical support board 4. The procedure for measuring the strength of compacted snow is as follows: holding the handle with your hand and placing one foot on the platform for the foot, move it to him the weight of his body. The immersion depth of the cone is determined by the scale on the vertical stop board. The strength of compacted snow, depending on the applied load and the depth of immersion of the cone, is determined by the formula
, kPa
( , kgf/cm 2),
Where σ - strength of compacted snow;
R- load on the cone (mass of the human operator);
h- immersion depth of the cone, cm.
Measurements of the strength of the snow cover are made along the axis of the runway after 25 m at the starting sections and after 100 m at the middle section.
One of the main elements of the airport, ensuring the safety of takeoff and landing operations and the regularity of flights, is the airfield. In accordance with the Air Code Russian Federation, “An airfield is a piece of land or water surface with buildings and structures located on it, intended for take-off, landing, taxiing and parking of aircraft.”
The safety of takeoff and landing operations, the movement of aircraft on the airfield, and the regularity of flights depend on the condition of the surface of the airfield.
Airfields with artificial surfaces
Cleaning artificial surfaces from dirt, dust, debris and other foreign objects;
Updating the markings of coatings and portable markings;
Checking the condition of the surface of coatings, reinforced interface areas and adjacent soil areas of the airfield, recording changes and defects in artificial surfaces;
Maintaining the levelness of the soil part of the airfield and the established height of the grass stand;
Sealing of seams.
Cleaning of coatings from dirt, debris, dust and other objects should be done using plow-brush machines.
After the end of the spring thaw, the coating must be washed, the water consumption is 1 l/m2. In the dry season of the year in summer, dust from the coating is washed off with water at a consumption rate of 0.3 l/m2.
Markings on artificial surfaces must be updated as the paint material fades and wears out (two to three times a year).
Portable markings must be repaired as the structure wears out and their painting must be renewed at least twice a year.
In the fall, before frost sets in, artificial surfaces must be repaired to prevent water from entering the base through cracks, and the unpaved part of the airfield must be graded.
Unpaved airfields
The operational maintenance of unpaved airfields is characterized by the strength of the airfield soil and its evenness.
Under the strength of the soil at refers to the ability of the soil to withstand the load from the wheels of the aircraft when the permissible rut depth is formed.
The aircraft's ground capability is characterized by:
Minimum soil strength at min, at which the aircraft can move off under the power of its own engines, gain speed sufficient for takeoff while ensuring stability during the take-off run, and taxi, forming a rut of the maximum permissible depth;
Operational strength of the soil at exp., in which a rut is formed that does not destroy the turf cover of the airfield.
Soil strength value at and rut depths N for aircraft are given in Table 1:
Table 1. Soil strength value
|
Aircraft type and weight, t |
, KPa (kgf/cm 2) |
H max, cm |
at exp., kPa (kgf/cm 2) |
|
|
M-15 xx (5.75) |
294,3-490,5 (3,6-5,0) |
294,3-490,5 (3,0-5,0) |
x - Normal tire pressure - 294.3 kPa (3 kgf/cm2).
xx - Reduced tire pressure - 196.2 kPa (2 kgf/cm2).
For helicopters of all types, the soil strength must be at least 294.3 kPa (3 kgf/cm2).
The strength of the soil is checked before the start of flights, in spring and autumn during the rainy season in the summer, after repairs and in each case when the condition of the soil changes. The strength of the soil is determined by the U-1 striker.
Due to severe waterlogging (in spring, autumn and during heavy rains in summer), the strength of the soil sharply decreases and the operation of aircraft becomes impossible. This period is called thaw or non-flying period.
Reducing the non-flying period is achieved:
Ensuring drainage and protection of the airstrip from the influx of atmospheric and melt water from adjacent areas;
Improving the quality of planning, increasing the degree of soil compaction of the airfield;
Reducing the take-off weight of the aircraft;
Installation of simplified coatings;
Creating a durable turf cover;
Timely clearing of snow from the airstrip in the pre-spring period.
Combing the grass and leveling uneven areas;
Rolling the turf cover;
Mowing grass.
Combing of the turf cover is carried out in the spring, after the top layer of soil has dried, in order to remove dried plants and improve soil aeration. Combing is performed twice with light zig-zag harrows.
To increase the strength of the soil and enhance the tillering of grasses, as well as to eliminate clumps and hummocks, a turf cover is rolled down. Rolling should be done with rollers when soil moisture is 2-3% higher than optimal. To enhance the growth of grasses in the dry season and especially in arid areas, it is recommended to carry out artificial watering (in the morning or evening).
The grass stand is mowed when it reaches a height of 30 cm. The last mowing to a grass stand height of 8 cm is carried out in the fall, before the onset of frost.
At airfields where there is a large concentration of birds, the grass should be mowed to a height of 20-25 cm.
To maintain the turf cover in constant operational readiness, it is necessary to eliminate ruts up to 6 cm deep immediately after the cessation of flights, by rolling with three- to five-ton rollers.
Sodding of ruts, potholes and areas with sparse grass is done by sowing grass or by replanting sod. For sowing, seeds are selected from three to seven herbs most suitable for the given area. The grass mixture should include turf-forming grasses from the cereal and legume families.
In places of transplantation, the sod is tightly laid and rolled. Places for sowing and transplanting turf are fertilized and watered.
To preserve the turf cover, it is necessary to carry out uniform operation of the airfield, for which it is necessary to fly aircraft from one start for no more than one to two weeks. After the specified period, the start must be transferred to another place.
Surface leveling and compaction;
Sealing ruts and uneven areas;
Fight against dust.
The leveling and compaction of the airstrip surface should be carried out in early spring and autumn before the onset of negative temperatures. Leveling work must be carried out in order to give the surface of the airfield a levelness that meets the safety requirements of aircraft and slopes that ensure the drainage of atmospheric and flood waters.
At airfields whose soils have rocky inclusions (crushed stone, gravel), leveling work must be carried out systematically, with the surface rolling using smooth rollers.
The sealing of ruts up to 6 cm and unevenness is carried out by cutting off the bumps and filling the depressions, followed by rolling them with three- to five-ton rollers.
Ruts more than 6 cm deep are filled with ordinary soil and then compacted. Filling ruts with sand, slag or other material different from the soil of the airstrip is not allowed.
The main measures to combat dust pollution are:
Watering is an ineffective method and requires a large consumption of water, therefore, as a rule, only the starting sections of the airstrip are watered;
Strengthening soils with inorganic binders - lime, which is added in the form of fluff or lime milk in a ratio of 1:5 in an amount of 5% of the weight of the treated layer;
Strengthening soils with organic binders - bitumen, bitumen emulsions, tars and oil production waste. The spill rate is 1-1.5 kg/m2.
The main works for the operational maintenance of airfields in winter are:
· cleaning airfield elements from snow (snow removal);
· prevention and removal of ice formations from surfaces (ice control);
· compaction of snow cover (snow compaction);
· snow protection of airfield elements from snow drifts;
· preparation and maintenance of heliports and landing sites.
At each airport and civil aviation department, no later than two months before the onset of negative temperatures, an action plan must be drawn up to prepare the airfield and airfield mechanization for work in the autumn-winter period. The plan should include measures for the maintenance and repair of airfield elements, restoration of coating markings and markings. In accordance with this plan, airfield machines and mechanisms must be repaired and equipped with radio communications, flashing and side lights.
The airfield service and special transport services must be staffed and production and technical training on the specifics of carrying out work to maintain the airfield in winter must be organized. The training is carried out using an album of technological maps, which is the main and mandatory document regulating the tactics of ice and snow removal work at the airfield. The album is compiled by the head (senior engineer) of the airfield service, who is also responsible for performing ice and snow removal work in accordance with the technological maps of this album.
The album of technological maps must contain:
· title page including the following information: complete official name airport, indicating the positions and names of the persons who approved, as well as the persons approving the technological maps; validity period of technological maps, month and year of their preparation;
· diagram of the airfield indicating the work related to the first stage of cleaning;
· scheme for organizing interaction and communication during ice and snow removal operations;
· a list of mechanization equipment available at the airport for ice and snow removal operations, indicating the main technical characteristics and appointments;
· technological maps for the main characteristic ice and snow removal work performed at the airport;
· sheet of changes and additions to technological maps.
Technological maps consist of initial data (name of an airfield element, characteristics of precipitation, wind speed and direction), movement patterns of harvesting machines, a table of required mechanization equipment and labor, a technological description of the work performed and a linear work schedule. The linear work schedule is drawn up only for ice removal work using chemical reagents and reflects the sequence of the following operations: unpacking, crushing and loading the chemical reagent into spreaders, scattering the reagent over the coating and removing the slush formed after melting the ice.
To ensure the regularity of flights and the rational use of mechanization equipment, all work during the winter period to clear snow and prepare airfield elements (if there is one runway) is divided into queues:
· first– cleaning of the runway, side safety strip (SSB) to a width of 10 m from the boundary of the runway, used for taxiing (working) taxiways with tilting shafts with rotary snow blowers, apron, restrictive “lights” (lights) along the boundaries of the runway and preparation of zone “A” for the course and glide path radio beacons (KRM and GRM);
· second– preparation of a spare main runway, cleaning of the MS, other taxiways, shoulders of all taxiways to a width of 10 m and station square;
· third– cleaning of the control center for half its length, the control center for a width of up to 25 m, MS shoulders and aprons with slope planning, access roads to radio communication facilities, fuel and lubricants, intra-port roads and other work.
For airfields that have two runways, the first stage of snow removal includes one runway, a 10-m BPS, working taxiways, zones “A” of the control and timing control points adjacent to this runway, the apron and lights (lamps) along the border of this runway. The second runway is cleared of snow in the second place.
Preparation of the airfield elements belonging to the first stage must be started by patrolling from the beginning of the snowfall and completed no later than 1 hour after it stops. After completion of the first stage of work, it is allowed to open the airfield for the reception and release of aircraft. Work related to subsequent stages must begin immediately after the completion of work in the first stage.
Mechanization equipment used for winter maintenance of airfields is conventionally divided into three groups:
· first– machines and mechanisms, the required number of which is determined based on the area being processed (snow plows, smoothers, rollers, etc.);
· second– machines and mechanisms, the number of which depends on the volume of snow being removed (rotary snow blowers, snow loaders, etc.);
· third– machines and mechanisms, the number of which cannot be determined by calculation (thermal engines, machines and mechanisms for dispersing chemical reagents). The number of such mechanization equipment is determined depending on the class of the airfield and climatic conditions.
During the winter maintenance of an airfield with artificial pavements under a compacted layer of snow and unpaved airfields, the priority work includes the preparation of the runway (RWY), zones “A” of the KRM and GPM, as well as the planning of runway shoulder interfaces (GWW). The second stage includes the preparation of the apron and taxiway, and the third stage includes the preparation of the KPB, MS, taxiway shoulders, apron and MS.
During the winter maintenance of the airfield, the airfield service practically interacts with all airport services, and primarily with the special transport and airfield mechanization service (SSTiAM), the traffic service (SD), the airfield meteorological station (AMSG), the aviation engineering service (IAS) and the electrical lighting service ensuring flights and electrical installations (ESTOP).
In order to prevent aviation accidents and the preconditions for them due to the occupancy of the runway by equipment or people during flight operations, each airline is developing a Technology for the interaction of services when performing work on the airfield, taking into account local conditions. Interaction technology is reviewed and clarified once a year.
The readiness of the airfield for flights is ensured by clearing the airfield pavements (runways, main landing stage, terminal and apron) from snow and ice, snow control surfaces for half their length from the runway end on each side, snow control surfaces on each side of the runway boundaries for a width of 25 m, and then they arrange junctions of snow with a slope of no more than 1/10, the sides of taxiways, interstates and aprons are cleared of snow to a width of 10 m with the construction of junctions of snow with a slope of no more than 1/10. To increase the regularity of aircraft flights, at least two runways are prepared and maintained on the airfield: the main runway and the reserve runway. In this case, the main runway must be cleared of snow for the length of the main runway, increased on each side by half the length of the runway and by the width: at airfields of classes A and B - 100 m, class B - 85 m, classes D and D - 75 m and class E – 60 m with a snow interface and a slope of no more than 1/10. The runway is used for aircraft flights during the clearing of snow and ice from the runway.
A layer of freshly fallen snow, slush and water is allowed on runway surfaces. The thickness of the atmospheric precipitation layer for various types of aircraft, at which flights are permitted, is indicated in the flight manual for a specific type of aircraft.
The areas to be cleared of the roadside road, roadside roadside, roadside, and apron must be of equal strength, while the strength of the soil and compacted snow is not standardized. In these areas, a layer of compacted snow up to 8 cm thick and a layer of freshly fallen snow up to 10 cm are allowed.
Airfield surfaces are cleared of snow using wind machines (VM), plow-brush-gas-jet machines (type DE-224) and plow-brush machines (type PM-130).
Wind machines clear snow from the runway at a side wind speed of up to 3 m/s from the runway axis to the sides, and at a side wind speed of more than 3 m/s in the wind direction, starting from the side of the runway to the place where the snow is laid out. Taxiways are cleared of snow by wind machines in one pass, moving along their sides at a distance of 4–6 m from the edge of the coverings, depending on the angle of inclination of the aircraft engine. Clearing snow from the apron and parking areas with wind machines can be carried out provided that there are no aircraft or other equipment on the surfaces. In this case, the snow is removed away from buildings and structures. Productivity and width of snow removal from surfaces using wind machines. The greatest effect from the use of such machines is achieved when patrolling snow up to 2 cm thick (productivity reaches 50–100 ha/h).
Coatings are cleaned of foreign objects to prevent them from entering aircraft engines and damaging compressor blades. Foreign objects include: crushed stone and the mortar part of collapsing concrete, particles of destroyed and peeled sealant from expansion joints, individual pieces of asphalt and cement concrete that have peeled off and broken off at the edges of seams and cracks, hardware and steel fluff from the brushes of airfield maintenance machines. In addition, foreign objects in the form of pieces of dirt, rubble and debris fall onto the coating by being carried from the unpaved areas of the airfield by wheels Vehicle and under the influence of air jets from aircraft engines. Airfield pavements must be cleaned at least twice a day, as a rule, without stopping flight operation of high-performance machines such as DE-224 and wind machines. The plow-brush-pneumatic machine DE-224 provides high-quality cleaning of coating surfaces in one pass. In this case, large objects are cleaned with a brush, and small objects are cleaned with a high-speed gas-air flow of an aircraft engine. High-quality cleaning of coatings from foreign objects can be carried out by a team of machines, including plow-brush machines of the PM-130 type and an electromagnetic cleaner EMO-2. Removal of foreign objects from the surface of the coatings is carried out with a brush, and cleaning of the coatings from metal objects, including the fluff of the brushes of PM-130 machines, is carried out by EMO-2. The disadvantage of this unit of machines is its low productivity. Thus, a set of machines consisting of six PM-130 machines and one EMO-2 electromagnetic cleaner has a productivity of 10–12 ha/h. Therefore, it is advisable to use this group of machines when cleaning MRD and RD coatings.
To reduce contamination of the surface of coatings with metal pile from PM-130 machines, it is necessary to monitor the correct setting of the height of the brushes and thereby prevent their destruction, and also to use the design of brushes with soft embedding of the pile, manufactured on the ShchNS-2 brush-winding machine. To identify potentially dangerous areas of coatings that have peeling, chipped edges, potholes and other damage, it is necessary to conduct regular inspections of the condition of coatings and draw up defect plans. According to these defective plans, repair work and filling of joints should be carried out in a timely manner. This will help eliminate one of the reasons for the penetration of coating destruction products into aircraft engines. The strength and erosion resistance of soil shoulders must be created by installing an artificial pavement made of asphalt concrete, stone materials or local soils treated with binding materials.
Washing of coatings produced after the end of the spring thaw, as well as as they become polluted. The movement of vehicles must be organized so that the surfaces are washed downhill. This achieves better washing and minimal water consumption (up to 1 l/m 3) with a maximum width of the washed strip.
Watering coatings with water It is produced in dry and hot times in order to moisten the surface to reduce their tension when exposed to high heating temperatures. The water consumption rate when watering coatings is assumed to be 0.3 l/m.
Restoration of coating markings produced as they become dirty and lose brightness. For marking artificial surfaces of airfields, EP-5135 (TU-1-10-1085-75) and NTs-25 (GOST 5406-84) enamels are used.
When marking runway surfaces, a certain sequence of markings must be observed, namely: center line, threshold signs, numeric and alphabetic signs, touchdown zone signs, fixed distance signs and edge lines.
The fencing of the airfield territory is arranged to prevent unimpeded entry of unauthorized persons, animals and vehicles onto the airfield, to ensure flight safety, taxiing and safety of aircraft, as well as equipment and signs. The airfield territory must have a fence that is rectilinear in plan and continuous along the perimeter of the airfield, including the zones of the working sectors of localizer and glide slope radio beacons.
On the day of airfields at airports of classes I and II, the fencing is made of solid reinforced concrete. At these airfields, taking into account the terrain, in certain areas it is allowed to construct a fence made of barbed wire 2.1 m high with a canopy up to 0.5 m wide in each direction made of barbed wire stretched every 10 cm. At class I and II airports located in In areas with increased snow accumulation (snow transfer of more than 200 m 3 per year), the installation of lattice reinforced concrete fences is allowed. Fencing with a solid reinforced concrete fence is primarily arranged from the side settlements and in places where unauthorized persons, vehicles and animals are most likely to enter. For airfields of class III–V airports, the fencing is usually made of barbed wire on reinforced concrete poles or of a metal mesh 2 m high with a T-shaped nozzle 0.1 m high and with a canopy 0.5 m wide on each side made of barbed wire , stretched every 10 cm. At these airports, it is allowed to construct fences from local materials (shell rock, tuff, slag concrete, etc.)
RESPONSIBILITIES OF THE PERSON RESPONSIBLE
The main responsibility of the person in charge of the airport is to maintain the airfield in constant operational readiness, ensuring the safe and regular operation of aircraft flights and the organization of their movement on the airfield.
The responsible person is obliged:
Carry out operational maintenance, repair and equipment of the airfield with markings in accordance with current requirements;
Develop and implement measures aimed at reducing delays and cancellations of aircraft flights due to airfield conditions;
Make decisions on termination, resumption or restriction of flights depending on the condition of the airfield;
Inspect the airfield before the opening of flights, after repair and maintenance work, changes in the condition of the airfield and precipitation. Record the inspection results daily, as well as when the condition of the airfield changes, in a special Logbook;
Systematically monitor the technical condition of the airfield and take measures to eliminate identified defects before the start of flights;
Check the flatness of the surface of the unpaved runway and determine the strength of the soil or compacted snow;
Take part in the development of plans for capital and current repairs of the airfield;
Timely organize and ensure the implementation of work on current and major repairs of the airfield;
Introduce progressive methods for repairing airfield pavements and other airfield structures;
Carry out technical supervision over compliance with the requirements of regulatory documents for the repair of airfields;
Be guided by safety requirements when carrying out work on the maintenance and repair of the airfield;
Ensure careful storage, proper use and economical expenditure of material resources allocated for airfield repairs;
Ensure standard service life of structures and equipment with minimal maintenance and repair costs;
Be guided by the instructions of the “Regulations on carrying out scheduled preventative repairs of civil aviation airfield airfield structures” when repairing airfield airfield structures;
Ensure the availability and storage of materials, equipment and mechanisms for the maintenance and repair of the airfield.
Airfields with artificial surfaces
When preparing an airfield for winter operation, you must:
Carry out leveling work, eliminate security guards, roll the surface of the airfield, mow the grass;
Perform routine repairs of artificial surfaces;
Restore the labeling of artificial surfaces;
Update portable markings;
Repair airfield vehicles and trailed mechanisms and prepare them for work in winter conditions;
Draw up a plan for the maintenance of the airfield for the winter period;
Prepare the necessary construction materials for repairing the airfield in winter, as well as dry sand to eliminate slippery conditions.
In areas with unstable negative air temperatures and frequent thaws, airfields with runways should be maintained by snow removal, and in areas with stable negative air temperatures - by snow compaction.
To ensure that the airfield is ready for flights in winter, the following requirements must be met:
The runway, taxiway, stopover and apron should be completely cleared of snow and ice;
Clear the KPB of snow by half their length on each side;
Clear the BBP of snow to a width of 25 m on each side, and then arrange junctions of snow with a slope of 1/10;
The shoulders of taxiways, stations and aprons should be cleared of snow to a width of 10 m with a snow interface device with a slope of 1/10.
On the cleared PPB, BPB and sides of taxiways, MS and apron, a layer of compacted snow up to 8 cm thick and a layer of freshly fallen snow up to 10 cm are allowed.
Clearing the runway from snow should be carried out by patrolling with snow plows and brushes from the beginning of the snowfall and end an hour after it stops for the entire width of the runway. The operation of snow plows and brushes must be organized in such a way that they move sequentially, one after the other, from the axis of the runway to the sides, overlapping the previous track by 0.3-0.4 m. The minimum distance between moving vehicles must be at least 30-35 m Snow collected in shafts is immediately removed by rotary snow blowers beyond the boundaries of the cleared strips or leveled on the adjacent unpaved part of the airfield.
Aircraft take-off and landing are allowed if there is dry, freshly fallen snow on the runway with a thickness of no more than 5 cm, slush of 12 mm and water of 10 mm.
The runway under a layer of compacted snow is prepared and maintained to the length of the runway, increased on each side by half the CPB, and a width of 60 m, consisting of the width of the runway and two equal parts of the MB. The thickness of the compacted snow layer should be within 6-8 cm. Connections made of uncompacted snow are arranged with a slope of 1/10. The requirements for the strength of compacted snow cover on a runway for various types of aircraft are the same as for unpaved airfields maintained by snow compaction.
When the runway is maintained under a layer of compacted snow, the first layer is created by compacting the snow with pneumatic rubber or rubber-concrete rollers, followed by smoothing with trowels. Subsequent snow compaction on the runway is carried out using the same technology as on the main runway. After creating a layer of compacted snow 6-8 cm thick, further maintenance of the runway is carried out by clearing snow.
As it is used, the snow on the runway is destroyed and blown away under the influence of wheels and air jets from aircraft engines. To restore the layer of compacted snow in such areas, it is necessary to compact the snow instead of clearing it.
Two to three weeks before the onset of positive air temperatures, the layer of compacted snow must be removed from the runway surfaces. Compacted snow is cut in layers 1-2 cm thick using a motor grader. The snow cut and collected into a shaft is removed outside the runway.
Clearing the runway from compacted snow continues until the surface is completely cleared.
Unpaved airfields
The operation of aircraft on unpaved airfields in winter is allowed under established negative air temperatures and freezing of the upper layers of soil for An-2, M-15 and L-410 aircraft to a depth of 5-6 cm. At a shallower freezing depth, it is necessary to determine the strength of the soil (Appendix 1) under a layer of frozen soil. If the strength of the soil meets the requirements for a particular type of aircraft, then its operation is permitted even at a lower depth of soil freezing.
Unpaved airfields, regardless of climatic conditions and location, are maintained by snow compaction.
The operational state of a dirt airfield in winter is characterized by the strength of compacted snow. Each type of aircraft has its own operational and minimum permissible strength of compacted snow.
If the compacted snow cover is operationally strong, regular aircraft flights are permitted, but the rut depth from the aircraft wheels should not exceed 2 cm.
With a minimum permissible strength, one-time aircraft flights are permitted, and the depth of the ruts from the aircraft wheels should not exceed 6 cm.
The strength of compacted snow cover for An-2, M-15, L-410M aircraft is as follows:
For regular flights (operational strength) 392.4 kPa (4 kgf/cm2);
For one-time flights (minimum strength) 294.3 kPa (3 kgf/cm2).
For helicopters of all types, the strength of the compacted snow cover must be at least 294.3 kPa (3 kgf/cm2).
The strength of the compacted snow cover is determined before the start of flights, after each snow compaction and when the temperature rises. The determination of the strength of compacted snow cover is given in Appendix 2.
Compaction of freshly fallen snow is carried out when the snow thickness is 5 cm and continues until the snowfall stops. To increase the strength of compacted snow, rolling of the runway should be carried out even when the air temperature rises, regardless of snowfall.
The snow is compacted first with trowels, then with rollers, followed by smoothing with trowels. To compact snow, trowels designed by NIAS, GVF, wide-grip with two inclined bottoms, which are manufactured by the airport, and pneumatic rubber, wooden, metal, rubber-concrete rollers weighing 10-15 tons are used.
Behind the side boundaries of the runway, gentle slopes with a slope of no more than 1/10 should be arranged, which must be graded.
Preparation of airfields for the operation of the An-2 aircraft on a ski chassis consists of eliminating irregularities (bumps, bumps, ruts) exceeding 25 cm, which is achieved with a one-time pass of a light smoothing iron.
Operation of aircraft with wheeled landing gear may be permitted if there is freshly fallen snow up to 5 cm thick on the surface.
Ruts, potholes, furrows and snow banks must be systematically leveled with snowdrift cutters and smoothers and compacted with rollers. Leveling ruts with a depth of up to 3 cm should be done by passing smoothers in the longitudinal direction; ruts more than 3 cm are leveled first by transverse and then longitudinal passes.
When the top layer of compacted snow cover icing, the ice crust should be destroyed with spike or ribbed rollers and then compacted with trowels and rollers.
To extend the service life of the airfield, it is necessary in the spring before the snow melts to systematically compact the airstrip, gradually reducing the layer of compacted snow. Snow compaction should be done in the afternoon so that under the influence of night frosts the snow acquires the necessary strength.
4.26. Before intensive snow melting begins, it is recommended to clear the airstrip of snow. Snow storage must be done in low areas outside the airfield in order to prevent its flooding with melt water. To prevent melt water from entering the cleared airstrip, drainage ditches must be installed. Depending on the terrain, drainage ditches are made on the side of possible water flow. Drainage ditches are made with a single-blade plow.