Glide path - what is it in aviation. Take-off and landing tractors Calculation of glide path angle

Approach- one of the final stages of an aircraft's flight, immediately preceding landing. Ensures that the aircraft is placed on a trajectory that is pre-landing line leading to the landing point.

The landing approach can be carried out either using radio navigation equipment (and in this case is called an instrument approach) or visually, in which the crew is oriented along the natural horizon line observed by the runway and other landmarks on the ground. In the latter case, the approach may be called a visual approach (VFR) if it is a continuation of an IFR flight (instrument flight rules) or a VFR approach if it is a continuation of a VFR flight (visual flight rules).

Glide slope(fr. glissade- “sliding”) - flight path aircraft, along which it descends immediately before landing. As a result of flying along the glide path, the aircraft enters the landing zone on the runway.

In paragliding, the base glide path is the straight path immediately before landing.

Glide slope angle is the angle between the glide path plane and the horizontal plane. The glide slope angle is one of the important characteristics of an airfield runway. For modern civil airfields it is usually in the range of 2-4.5°. The glide slope angle may be affected by the presence of obstacles in the airfield area.

In the Soviet Union, the typical value of the glide path angle was 2°40′. International organization civil aviation recommends UNG 3°.

Also, the process of descending an aircraft before landing is sometimes called a glide path.

Compared to other types of aircraft, the aircraft has the longest take-off phase and the most difficult to organize control. Take-off begins from the moment you start moving along the runway for the take-off run and ends at the transition altitude.

Take-off is considered one of the most difficult and dangerous stages of flight: during take-off, engines operating under conditions of maximum thermal and mechanical load may fail, the aircraft (relative to other phases of flight) is maximally fueled, and the flight altitude is still low. The biggest disaster in aviation history occurred on takeoff.

Specific takeoff procedures for each aircraft type are described in the aircraft manual. flight operation airplane. Adjustments can be made by exit schemes and special conditions (for example, noise reduction rules), however, there are some general rules.

For acceleration, engines are usually set to takeoff mode. This is an emergency mode, the flight duration is limited to a few minutes. Sometimes (if the runway length allows) during takeoff, the nominal mode is acceptable.

Before each takeoff, the navigator calculates the decision speed (V 1), up to which the takeoff can be safely aborted and the aircraft will stop within the runway. The calculation of V 1 takes into account many factors, such as: runway length, its condition, coverage, altitude above sea level, weather conditions (wind, temperature), aircraft loading, alignment, and others. If the failure occurs at a speed greater than V1, the only solution is to continue the takeoff and then land. Most types of civil aviation aircraft are designed in such a way that, even if one of the engines fails on takeoff, the power of the others is sufficient to accelerate the aircraft to a safe speed and rise to the minimum altitude from which it is possible to enter the glide path and land the aircraft.

Before takeoff, the pilot lowers the flaps and slats to the designed position to increase lift while minimizing the aircraft's acceleration. Then, after waiting for permission from the air traffic controller, the pilot sets the engines to takeoff mode and releases the wheel brakes, and the plane begins its takeoff run. During the takeoff run, the pilot’s main task is to keep the car strictly along its axis, preventing its lateral displacement. This is especially important in windy weather. Up to a certain speed, the aerodynamic rudder is ineffective and steering occurs by braking one of the main landing gear. After reaching the speed at which the rudder becomes effective, control is performed by the rudder. The nose landing gear on the take-off run is usually locked for turning (the aircraft turns with its help while taxiing). As soon as takeoff speed is reached, the pilot smoothly takes the helm, increasing the angle of attack. The nose of the plane rises (“Lift”), and then the entire plane lifts off the ground.

Immediately after lift-off, to reduce drag (at a height of at least 5 meters), the landing gear and (if any) exhaust lights are retracted, then the wing mechanization is gradually retracted. Gradual retraction is due to the need to slowly reduce the lift of the wing. If the mechanization is quickly retracted, the aircraft may drop dangerously. In winter, when the plane flies into relatively warm layers of air where engine efficiency drops, the drawdown can be especially deep. Approximately according to this scenario, the Ruslan disaster occurred in Irkutsk. The procedure for retracting the landing gear and wing mechanization is strictly regulated in the Flight Manual for each type of aircraft.

Once the transition altitude is reached, the pilot sets the standard pressure to 760 mm Hg. Art. Airports are located at different altitudes, and management by air is carried out in a single system, therefore, at the transition altitude, the pilot is required to switch from the altitude reference system from runway level (or sea level) to flight level (conditional altitude). Also, at the transition height, the engines are set to the nominal mode. After this, the take-off stage is considered completed, and the next stage of the flight begins: climb.

There are several types of aircraft takeoff:

• Taking off from the brakes. The engines are brought to maximum thrust mode, at which the aircraft is held on the brakes; after the engines have reached the set mode, the brakes are released and the take-off run begins.
• Takeoff with a short stop on the runway. The crew does not wait until the engines reach the required mode, but immediately begins the takeoff run (the engines must reach the required power up to a certain speed). At the same time, the takeoff length increases.
• Take off without stopping rolling start), "on the fly." The engines reach the desired mode during taxiing from the taxiway to the runway; it is used during high intensity flights at the airfield.
• Takeoff using special means. Most often, this is a takeoff from the deck of an aircraft-carrying ship under conditions of a limited runway length. In such cases, the short takeoff run is compensated by springboards, ejection devices, additional solid-fuel rocket engines, automatic landing gear wheel holders, etc.
• Taking off an aircraft with a vertical or short take-off. For example, the Yak-38.
• Taking off from the surface of the water.

Those who live near airports know: most often, taking off airliners soar upward along a steep trajectory, as if trying to get away from the ground as quickly as possible. And indeed, the closer the ground, the less opportunity to react to emergency and make a decision. Landing is another matter.

And the 380 lands on a runway covered with water. Tests have shown that the aircraft is capable of landing in crosswinds with gusts of up to 74 km/h (20 m/s). Although reverse braking devices are not required by the FAA and EASA, designers Airbus decided to equip two engines with them, located closer to the fuselage. This made it possible to obtain an additional braking system, while reducing operating costs and reducing preparation time for the next flight.

A modern jet passenger airliner is designed to fly at altitudes of approximately 9-12 thousand meters. It is there, in very rarefied air, that it can move in the most economical mode and demonstrate its optimal speed and aerodynamic characteristics. The period from the completion of the climb to the start of the descent is called the flight at cruising level. The first stage of preparation for landing will be the descent from the flight level, or, in other words, following the arrival route. The final point of this route is the so-called initial approach checkpoint. In English it is called Initial Approach Fix (IAF).

And the 380 lands on a runway covered with water. Tests have shown that the aircraft is capable of landing in crosswinds with gusts of up to 74 km/h (20 m/s). Although reverse braking devices are not required by the FAA and EASA, Airbus designers decided to equip the two engines located closer to the fuselage with them. This made it possible to obtain an additional braking system, while reducing operating costs and reducing preparation time for the next flight.

From the IAF point, movement begins according to the approach to the airfield and landing approach, which is developed separately for each airport. An approach according to the pattern involves a further descent, passing a trajectory defined by a number of control points with certain coordinates, often performing turns and, finally, entering the landing line. At a certain landing point, the airliner enters the glide path. The glide path (from the French glissade - sliding) is an imaginary line connecting the entry point to the beginning of the runway. Following the glide path, the aircraft reaches the MAPt (Missed Approach Point), or missed approach point. This point is passed at the decision altitude (DAL), that is, the altitude at which the missed approach maneuver must be initiated if, before reaching it, the pilot-in-command (PIC) has not established the necessary visual contact with landmarks to continue the approach. Before the flight, the PIC must already assess the position of the aircraft relative to the runway and give the command “Land” or “Leave”.

Landing gear, flaps and economy

On September 21, 2001, an Il-86 aircraft belonging to one of Russian airlines, landed at Dubai airport (UAE) without extending the landing gear. The case ended with a fire in two engines and the aircraft being written off - fortunately, no one was injured. There was no talk of a technical malfunction, they just forgot to release the landing gear.

Modern airliners, compared to aircraft of previous generations, are literally packed with electronics. They implement a fly-by-wire remote control system (literally “fly on a wire”). This means that the steering wheels and mechanization are driven by actuators that receive commands in the form of digital signals. Even if the plane is not flying in automatic mode, the movements of the helm are not transmitted directly to the rudders, but are recorded in the form of a digital code and sent to a computer, which will instantly process the data and issue a command to the actuator. In order to increase the reliability of automatic systems, the aircraft is equipped with two identical computer devices (FMC, Flight Management Computer), which constantly exchange information, checking each other. A flight mission is entered into the FMC indicating the coordinates of the points through which the flight path will pass. Electronics can guide the aircraft along this trajectory without human intervention. But the rudders and mechanization (flaps, slats, spoilers) of modern airliners are not much different from the same devices in models produced decades ago. 1. Flaps. 2. Interceptors (spoilers). 3. Slats. 4. Ailerons. 5. Rudder. 6. Stabilizers. 7. Elevator.

Economics has something to do with the background to this accident. The approach to the airfield and landing approach are associated with a gradual decrease in the speed of the aircraft. Since the amount of wing lift is directly dependent on both the speed and the wing area, in order to maintain enough lift to keep the car from stalling into a tailspin, the wing area must be increased. For this purpose, mechanization elements are used - flaps and slats. Flaps and slats perform the same role as the feathers that birds fan out before landing on the ground. When the speed of the start of mechanization extension is reached, the PIC gives the command to extend the flaps and, almost simultaneously, to increase the engine operating mode to prevent a critical loss of speed due to an increase in drag. The greater the angle the flaps/slats are deflected, the greater the operating mode required by the engines. Therefore, the closer to the runway the final release of the mechanization (flaps/slats and landing gear) occurs, the less fuel will be burned.

On domestic aircraft of older types, this sequence of mechanization release was adopted. First (20-25 km before the runway) the landing gear was released. Then, after 18-20 km, the flaps were set to 280. And already on the landing straight, the flaps were extended fully, to the landing position. However, nowadays a different technique has been adopted. In order to save money, pilots strive to fly the maximum distance “on a clean wing”, and then, before the glide path, reduce the speed by intermediately extending the flaps, then lower the landing gear, bring the flap angle to the landing position and land.

The figure shows a very simplified diagram of the approach and takeoff in the airport area. In fact, the schemes may differ noticeably from airport to airport, as they are compiled taking into account the terrain, the presence of high-rise buildings and no-fly zones nearby. Sometimes several schemes operate for the same airport depending on weather conditions. For example, in Moscow Vnukovo, when entering the runway (GDP 24), the so-called a short scheme, the trajectory of which lies outside the Moscow Ring Road. But in bad weather, planes enter in a long pattern, and the liners fly over the South-West of Moscow.

The crew of the ill-fated Il-86 also used the new technique and extended the flaps to the landing gear. Knowing nothing about new trends in piloting, the Il-86 automatic system immediately turned on a voice and light alarm, which required the crew to lower the landing gear. So that the alarm would not irritate the pilots, it was simply turned off, like turning off a boring alarm clock when you are asleep. Now there was no one to remind the crew that the landing gear still needed to be lowered. Today, however, there have already appeared examples of Tu-154 and Il-86 aircraft with modified signaling, which fly according to the approach method with the late release of mechanization.

According to actual weather

In news reports you can often hear a similar phrase: “Due to deteriorating weather conditions in the area of ​​airport N, the crews make decisions about takeoff and landing based on the actual weather.” This common cliche causes both laughter and indignation among domestic aviators. Of course, there is no arbitrariness in flying. When the aircraft passes the decision point, the pilot-in-command (and only he) makes the final call on whether the crew will land the aircraft or whether the landing will be aborted by a go-around. Even with the best weather conditions and the absence of obstacles on the runway, the pilot has the right to cancel the landing if, as the Federal Aviation Regulations say, he is “not confident in the successful outcome of the landing.” “Today a go-around is not considered a miscalculation in the pilot’s work, but, on the contrary, is welcomed in all doubtful situations. It’s better to be vigilant and even sacrifice some amount of burned fuel than to put even the slightest risk to the lives of passengers and crew,” Igor Bocharov, chief of the flight operations headquarters of S7 Airlines, explained to us.

The course-glide path system consists of two parts: a pair of localization beacons and a pair of glide path beacons. Two localizers are located behind the runway and emit a directed radio signal along it at different frequencies at small angles. On the runway centerline, the intensity of both signals is the same. To the left and right of this direct signal, one of the beacons is stronger than the other. By comparing the intensity of the signals, the aircraft's radio navigation system determines which side and how far it is from the center line. Two glide path beacons are located in the area of ​​the landing zone and act in a similar way, only in the vertical plane.

On the other hand, the PIC is strictly limited in decision-making by the existing landing procedure regulations, and within the limits of these regulations (except for emergency situations such as a fire on board) the crew does not have any freedom to make decisions. There is a strict classification of landing approach types. For each of them, separate parameters are prescribed that determine the possibility or impossibility of such a landing under given conditions.

For example, for Vnukovo airport, an instrument approach using a non-precision type (via radio stations) requires passing a decision point at an altitude of 115 m with a horizontal visibility of 1700 m (determined by the weather service). In order to land before the runway (in this case 115 m), visual contact with landmarks must be established. For automatic landing according to ICAO category II, these values ​​are much smaller - they are 30 m and 350 m. Category IIIc allows for fully automatic landing with zero horizontal and vertical visibility - for example, in complete fog.

Safe hardness

Any air passenger with experience of flying with domestic and foreign airlines has probably noticed that our pilots land planes “softly”, while foreign ones land them “hard”. In other words, in the second case, the moment of touching the runway is felt in the form of a noticeable push, while in the first case, the plane gently “rubs” against the runway. The difference in landing style is explained not only by the traditions of flight schools, but also by objective factors.

First, let's clarify terminology. In aviation usage, a hard landing is a landing with an overload that greatly exceeds the norm. As a result of such a landing, the aircraft, in the worst case, receives damage in the form of residual deformation, and in the best case, it requires special maintenance aimed at additional monitoring of the condition of the aircraft. As Igor Kulik, leading pilot instructor of the flight standards department of S7 Airlines, explained to us, today a pilot who makes a real hard landing is suspended from flying and sent for additional training on simulators. Before taking off again, the offender will also have to undergo a test flight with an instructor.

The landing style on modern Western aircraft cannot be called hard - we are simply talking about increased overload (about 1.4-1.5 g) compared to 1.2-1.3 g, characteristic of the “domestic” tradition. If we talk about piloting techniques, the difference between landings with relatively less and relatively more overload is explained by the difference in the procedure for leveling the aircraft.

The pilot begins alignment, that is, preparation for touching the ground, immediately after flying over the end of the runway. At this time, the pilot takes the helm, increasing the pitch and moving the aircraft to a nose-up position. Simply put, the plane “lifts its nose,” which results in an increase in the angle of attack, which means a slight increase in lift and a drop in vertical speed.

At the same time, the engines are switched to the “idle gas” mode. After some time, the rear landing gear touches the strip. Then, reducing the pitch, the pilot lowers the nose gear onto the runway. At the moment of contact, spoilers (spoilers, also known as air brakes) are activated. Then, reducing the pitch, the pilot lowers the front strut onto the runway and turns on the reverse device, that is, additionally braking with the engines. Wheel braking is used, as a rule, in the second half of the run. The reverse is structurally made up of flaps that are placed in the path of the jet stream, deflecting some of the gases at an angle of 45 degrees to the course of the aircraft - almost in the opposite direction. It should be noted that on older domestic aircraft, the use of reverse during the run is mandatory.

Silence overboard

On August 24, 2001, the crew of an Airbus A330 flying from Toronto to Lisbon discovered a fuel leak in one of the tanks. It happened in the skies over the Atlantic. The ship's commander, Robert Pisch, decided to leave for an alternate airfield located on one of the Azores islands. However, along the way, both engines caught fire and failed, and there were still about 200 kilometers left to the airfield. Rejecting the idea of ​​landing on water, as giving virtually no chance of salvation, Pish decided to reach land in gliding mode. And he succeeded! The landing turned out to be hard - almost all the tires burst - but no disaster occurred. Only 11 people received minor injuries.

Domestic pilots, especially those operating Soviet-type airliners (Tu-154, Il-86), often complete the leveling procedure with a holding procedure, that is, they continue to fly over the runway for some time at an altitude of about a meter, achieving a soft touch. Of course, passengers like landings with holding more, and many pilots, especially those with extensive experience in domestic aviation, consider this style to be a sign of high skill.

However, today's global trends in aircraft design and piloting give preference to landing with an overload of 1.4-1.5 g. Firstly, such landings are safer, since a holding landing contains the threat of rolling out of the runway. In this case, the use of reverse is almost inevitable, which creates additional noise and increases fuel consumption. Secondly, the very design of modern passenger aircraft provides for contact with increased overload, since the activation of automation, for example, the activation of spoilers and wheel brakes, depends on a certain value of the physical impact on the landing gear (compression). In older types of aircraft this is not required, since the spoilers are turned on automatically after turning on the reverse. And the reverse is activated by the crew.

There is another reason for the difference in landing style, say, on the Tu-154 and A 320, which are similar in class. Runways in the USSR were often characterized by low load load, and therefore Soviet aviation tried to avoid too much pressure on the surface. The rear trolleys of the Tu-154 have six wheels - this design helped distribute the weight of the vehicle over large area upon landing. But the A 320 has only two wheels on racks, and it was originally designed for landing with a higher overload on more durable strips.

The island of Saint Martin in the Caribbean, divided between France and the Netherlands, has become famous not so much for its hotels and beaches, but for the landings of civilian airliners. Heavy wide-body aircraft such as Boeing 747 or A-340 fly to this tropical paradise from all over the world. Such cars need a long run after landing, but at Princess Juliana Airport the runway is too short - only 2130 meters - its end is separated from the sea only by a narrow strip of land with a beach. To avoid rolling out, Airbus pilots aim at the very end of the runway, flying 10-20 meters above the heads of vacationers on the beach. This is exactly how the glide path is laid out. Photos and videos of landings on the island. Saint-Martin has long been bypassed on the Internet, and many at first did not believe in the authenticity of these filmings.

Trouble on the ground

And yet, really hard landings, as well as other troubles, do happen during the final leg of the flight. As a rule, air accidents are caused by not one, but several factors, including piloting errors, equipment failure, and, of course, the elements.

The greatest danger is posed by the so-called wind shear, that is, a sharp change in wind strength with height, especially when this occurs within 100 m above the ground. Suppose an airplane is approaching the runway at an indicated speed of 250 km/h with zero wind. But, having descended a little lower, the plane suddenly encounters a tailwind with a speed of 50 km/h. The incoming air pressure will drop, and the plane's speed will be 200 km/h. The lift will also decrease sharply, but the vertical speed will increase. To compensate for the loss of lift, the crew will need to add engine mode and increase speed. However, the plane has a huge inertial mass, and it simply will not have time to instantly gain sufficient speed. If there is no headroom, a hard landing cannot be avoided. If the airliner encounters a sharp gust of headwind, the lifting force, on the contrary, will increase, and then there will be a danger of a late landing and rolling out of the runway. Landing on a wet and icy runway also leads to rollouts.

Man and machine

Approach types are divided into two categories, visual and instrumental.
The condition for a visual approach, as with an instrument approach, is the height of the cloud base and the runway visual range. The crew follows the approach pattern, guided by the landscape and ground objects or independently choosing the approach trajectory within the designated visual maneuvering zone (it is set as a half circle with the center at the end of the runway). Visual landings allow you to save fuel by choosing the shortest approach trajectory at the moment.
The second category of landings is instrumental (Instrumental Landing System, ILS). They, in turn, are divided into accurate and inaccurate. Precision landings are carried out using a course-glide path, or radio beacon, system, using localizer and glide path beacons. The beacons form two flat radio beams - one horizontal, depicting the glide path, the other vertical, indicating the course to the runway. Depending on the equipment of the aircraft, the course-glide path system allows for automatic landing (the autopilot itself guides the plane along the glide path, receiving a signal from radio beacons), director landing (on the command instrument, two director bars show the positions of the glide path and course; the task of the pilot, working at the helm, is to place them accurately in the center of the command device) or approach using beacons (crossed arrows on the command device depict the course and glide path, and the circle shows the position of the aircraft relative to the required course; the task is to align the circle with the center of the crosshair). Non-precision landings are performed in the absence of a glide path system. The line of approach to the end of the strip is set by radio equipment - for example, far and near driving radio stations with markers installed at a certain distance from the end (DPRM - 4 km, BPRM - 1 km). Receiving signals from the "drives", the magnetic compass in the cockpit shows whether the aircraft is to the right or left of the runway. At airports equipped with a course-glide path system, a significant portion of landings are made using instruments in automatic mode. The international organization ICFO has approved a list of three categories of automatic landing, with category III having three subcategories - A, B, C. For each type and category of landing, there are two defining parameters - the horizontal visibility distance and the vertical visibility height, also known as the decision height. In general, the principle is this: the more automation is involved in landing and the less the “human factor” is involved, the lower the values ​​of these parameters.

Another scourge of aviation is crosswinds. When, when approaching the end of the runway, the plane flies at a drift angle, the pilot often has the desire to “turn” the control wheel and put the plane on the exact course. When turning, a roll occurs, and the plane exposes a large area to the wind. The liner blows even further to the side, and in this case the only correct decision is a go-around.

In crosswinds, the crew often tries not to lose control of direction, but ends up losing control of altitude. This was one of the reasons for the Tu-134 crash in Samara on March 17, 2007. The combination " human factor" With bad weather cost the lives of six people.

Sometimes incorrect vertical maneuvering during the final leg of the flight leads to a hard landing with catastrophic consequences. Sometimes the plane does not have time to descend to the required altitude and ends up above the glide path. The pilot begins to “give back the helm”, trying to enter the glide path. At the same time, the vertical speed increases sharply. However, with an increased vertical speed, a greater height is required at which leveling must begin before touching down, and this dependence is quadratic. The pilot begins leveling off at a psychologically familiar altitude. As a result, the aircraft touches the ground with a huge overload and crashes. The history of civil aviation knows many such cases.

Airliners of the latest generations can well be called flying robots. Today, 20-30 seconds after takeoff, the crew can, in principle, turn on the autopilot and then the car will do everything itself. If no emergency occurs, if an accurate flight plan is entered into the on-board computer database, including the approach path, if the arrival airport has the appropriate modern equipment, the airliner will be able to fly and land without human intervention. Unfortunately, in reality, even the most advanced technology sometimes fails; aircraft of outdated designs are still in operation, and the equipment of Russian airports continues to leave much to be desired. That is why, when rising into the sky and then descending to the ground, we still largely depend on the skill of those who work in the cockpit.

We would like to thank the representatives of S7 Airlines for their help: Il-86 instructor pilot, Chief of Flight Operations Staff Igor Bocharov, Chief Navigator Vyacheslav Fedenko, Instructor Pilot of the Flight Standards Department Directorate Igor Kulik

Author: Dmitry Prosko Date: 02/06/2005 23:20
The course-glide path system (hereinafter we will call it KGS, as is customary in Russia) is the most common approach system at large and busy airfields. In addition, it is the most accurate, unless, of course, you count MLS - Microwave Landing System, which has not yet received the same wide distribution. Now we will try to figure out how this system works and how to teach how to use it. Of course, this article does not claim to be the most complete and only correct guide :), but as a teaching aid at the initial stage it will help you a lot.

Composition and principle of operation of the CGS

All that we see on the instruments during landing are 2 intersecting bars indicating the position of the aircraft relative to the approach path. Let's try to understand why they move, and why the aircraft's flight and navigation system receives very accurate information about the aircraft's position.

So, what does the CGS consist of:

1. A localization beacon that provides guidance to the aircraft in the horizontal plane - along the course.
2. Glide path beacon that provides guidance in the vertical plane - along the glide path.
3. Markers signaling the moment of passing certain points on the approach trajectory. Typically markers are installed on DPRM and BPRM.
4. Receiving devices on board an aircraft that provide signal reception and processing.

Localization and glide path beacons are installed near the runway. Localizer - at the opposite end of the runway along the center line, glide path beacon on the side of the runway at a distance from the landing point from the runway threshold.

Now let's talk about how these beacons work. Let's take the localizer as a basis and look at its operation in a somewhat simplified manner. During operation, the beacon generates 2 different-frequency signals, which can be schematically shown as 2 lobes directed along the approach path.

If the plane is located exactly at the intersection of these two lobes, the power of both signals is the same, respectively, the difference in their powers is zero, and the instrument indicators show 0. We are on course. If the plane deviates to the left or to the right, then one signal begins to prevail over the other. And the further from the course line, the greater this predominance. As a result, due to the difference in signal strength, the aircraft receiver determines exactly how far we are from the course line.

The glide path beacon works exactly on the same principle, only in the vertical plane.

Reading instrument readings

So, we entered the KGS coverage area. The standards for the PNP have gone off scale, which means it’s time for us to figure out where we are and how we need to pilot the plane in order to accurately fit into the approach trajectory.

Depending on what device we have installed, the indication may change, but the basic principle remains unchanged - the bars (arrows, indices) show us the position approach trajectory relative to our location. On the instrument that we are now considering, our position relative to the course is shown by a vertical bar, and our position relative to the glide path is shown by a triangular index on the right side of the instrument.

The bars themselves seem to show us exactly where our trajectory is. If the course bar is on the left, then the course line is also on the left, which means we need to turn left. The same is true for the glide path - if the glide path index is lower, then we are going higher, and we need to increase the vertical speed in order to “catch up” with the glide path.

Now let's go through the different positions of the aircraft and look at the instrument display in the positions indicated in the general drawing.

1. We are on the course line and have not yet approached the glide path entry point. Everything is as it should be - the heading bar is exactly in the center, the glide path index is at the top. The glide path line passes above us and rushes into nowhere at an average angle of 2 degrees 40 minutes relative to the horizon. By the way, the glide slope angle (GSA) is different at different airfields. This depends on the terrain and other conditions. For example, at mountain airfields the temperature can be up to 4-5 degrees.

2. We are at the glide path entry point (GPS). This is the point formed by the intersection of the glide path with the height of the circle. The average distance of the TVG is approximately 12 km. Naturally, the higher the height of the circle and the smaller the UNG, the farther the TVG is from the runway threshold.

3. We are to the left and higher. We need to turn right and increase the rate of descent.

4. We are to the left and below. Let's tidy up the vertical one and turn it to the right.

5. We are to the right and higher. Let's move it to the left and increase the vertical one.

6. We are to the right and lower. Guess what needs to be done :)

Well, in general, that's all I wanted to tell you :)

Finally, I want to make one very important addition.

Please note that the closer we are to the runway, the less evolution of the aircraft should be, because the device becomes very sensitive. For example, if we are 10 km from the runway threshold, the position of the directional bar at the second point of the scale may mean a lateral deviation of 400 meters or more (this is for example). To complete the turn, we will need to change course by 4-5 degrees or more. If we are at a distance of 2 km, then this position of the bar means that the deviations have exceeded the maximum permissible, and the only thing left for us is to go around. The closer the plane is to the runway threshold, the closer to the center the directional bar should be. Ideally, of course, exactly in the center :) And accordingly, the closer we are, the less evolution of the aircraft should be. There is no point in introducing a 30-degree roll in the near-drive area. Firstly, it’s dangerous at such a height, and secondly, you simply won’t have time to turn it, given the inertia of the plane.

Glide slope

Glide path

the straight-line trajectory of an aircraft or glider during landing. The descent along the glide path at an angle of 0.046-0.087 rad (2.64-5.0 degrees) to the horizontal plane provides the aircraft with a smooth, gliding and significantly reduces the dynamic load at the moment of touching the runway. This is especially important for large passenger airliners and heavy transport aircraft. At airfields, the glide path is set using two radio beacons - glide path and localizer, which send radio beams in the direction of the landing aircraft, indicating the boundaries of the glide path in the inclined horizontal and vertical planes. The aircraft begins to descend along the glide path from an altitude of 200–400 m, the height of the glide path above the end of the runway is 15 m. If the aircraft's descent trajectory deviates from the glide path more than permissible, it must stop descending and gain altitude for a repeat approach.

Encyclopedia "Technology". - M.: Rosman. 2006 .

Glide slope

(French glissade, literally - sliding)
1) rectilinear trajectory of the aircraft at an angle to the horizontal plane.
2) The straight-line trajectory along which the aircraft should descend during the landing approach. The nominal value of the angle of inclination of the horizontal plane to the horizontal plane is 0.046 rad; in exceptional cases, the angle of inclination of the horizontal plane can reach 0.087 rad. At airfields, the glide path is set using the glide slope (GRM) and localization (LOC) radio beacons that are part of the airfield equipment. G. is formed by the intersection in space of two equal-signal zones of the timing and control gear. The height of the equal-signal timing zone above the end of the runway is 15 m. Aircraft movement along the horizontal plane begins at an altitude of 200-400 m and ends with a leveling maneuver or go-around if the deviation from the horizontal plane exceeds the permissible limit.

Aviation: Encyclopedia. - M.: Great Russian Encyclopedia. Editor-in-Chief G.P. Svishchev. 1994 .

Synonyms:

See what “glide path” is in other dictionaries:

- (French glissade, from glisser to slide). Easy jump. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. Glide path French. glissade, from glisser, to slide. Easy jump. Explanation of 25,000 foreign words included in... ... Dictionary of foreign words of the Russian language

glide path- y, w. glissade f. 1. Same as Glissade. 2. The flight path of an airplane, helicopter, glider, etc. during descent. BAS 2. The plane enters the final final glide path. Sov. Ross. 7. 5. 1966. And its speed is also impossible to reduce: ... ... Historical Dictionary of Gallicisms of the Russian Language

Trajectory, radio glide path, slip Dictionary of Russian synonyms. glide path noun, number of synonyms: 3 radio glide path (1) ... Synonym dictionary

- (French glissade lit. sliding), flight path of an airplane, helicopter, glider when descending... Big Encyclopedic Dictionary

Glide slope- descent profile established for vertical guidance at the final stage of landing... Source: Order of the Ministry of Transport of Russia dated November 25, 2011 N 293 (as amended on April 26, 2012) On approval of the Federal Aviation Rules Organization of air... ... Official terminology

Y; and. [French glissade] Air. The descent trajectory of an airplane, helicopter, glider. * * * glide path (French glissade, literally sliding), the flight path of an airplane, helicopter, glider during descent. * * * GLISSED GLASSED (French glissade, lit.... ... encyclopedic Dictionary

The ground equipment of the ILS system consists of a localizer and glide slope radio beacon and three marker radio beacons (currently, the near marker is not installed at all airports). At some airports, a drive radio station is installed at a distant marker point to construct an approach maneuver.

When performing international flights, you can find two options for placing ground equipment.

• The first option: the localizer is located on the extension of the runway axis and the center line of the heading zone coincides with the runway axis, i.e. its location corresponds to the landing angle (landing course).
• Second option: the localizer is not located on the runway axis, but to the right or left of it, so that the center line of the course zone passes through the middle marker point at an angle of 2.5-8° to the landing line.

The localizers of the ILS system operate in a circular manner. Recently, beacons of the sector version have been installed: the angular width of the sector is 70° on both sides of the landing line. The main characteristics of the ILS heading and glide path zones are given in the SP-50 ground equipment section, since they coincide with the corresponding characteristics of the SP-50 with the new adjustment.

The marker beacons of the ILS system operate at the same frequency (75 MHz) as in the SP-50 system and emit the following code signals: near marker - six points per second; middle marker - alternately two dashes and six dots per second; far marker (in ICAO materials - outer marker) - two dashes per second.

Ground equipment of the SP-50 system is located at civil aviation airports according to a single standard layout.

As a result of the adjustment of the equipment of the SP-50 system in accordance with the ICAO standards adopted for the ILS system, the localizer and glide slope radio beacons have the following technical data.

Localizer area. The center line of the course zone is aligned with the runway axis. The linear width of the zone at a distance of 1350 m from the landing point is 150 m (ranging from 120 to 195 m), which corresponds to an angular deviation from the longitudinal axis of the runway of no less than 2° and no more than 3°.

The range of the beacon ensures the reception of signals at a distance of more than 70 km from the beginning of the runway at a flight altitude of 1000 m in a sector 10° wide on each side of the runway axis (see 91). For the HUD localizer, the operating range is regulated at 45 km at a flight altitude of 600 m.

Glide path beacon zone. The optimal glide slope angle is 2°40". If there are obstacles in the approach sector, the glide slope angle increases to 3°20" and in exceptional cases can reach 4-5°. With an optimal descent glide path angle of 2°40", the aircraft during its descent flies over the far and near markers (at their standard location) at altitudes of 200 and 60 m, respectively.

The angular width of the glide path zone at an optimal angle of inclination can be in the range of 0.5-1°4, and with an increase in the angle of inclination, the speed of descent increases, and the width of the zone increases to make it easier to pilot the aircraft.

The range of the glide slope radio beacon ensures reception of signals at a distance of at least 18 km from it in 8® sectors to the right and left of the landing line. These sectors, in which signals are received, are limited in height by an angle above the horizon equal to 0.3 of the descent glide path angle, and by an angle above the glide path equal to 0.8 of the descent glide path angle.

The ground equipment of the SP-50M system is intended for use during direct and automatic landing approaches in accordance with ICAO standards of the 1st category of complexity.

The stability of the course centerline is ensured by more stringent requirements for the equipment.

In cases where the length of the runway significantly exceeds the optimal one, the width of the heading zone is set to at least 1°75" (half zone).

All other parameters of course and glide path beacons are regulated strictly in accordance with ICAO technical standards.

Approach director control systems

Currently, civil aviation aircraft with gas turbine engines are equipped with director (command) approach control systems (“Drive”, “Path”). These systems are systems for semi-automatic control of an aircraft during landing.

The command device in such systems is the PSP-48 or KPP-M null indicator.

Semi-automatic control should be understood as piloting an aircraft using a command instrument, the needles of which must be kept at zero during the landing approach from the moment the fourth turn begins and on the landing straight. Unlike a conventional SP-50 approach, the null indicator in this case does not inform the pilot about the position relative to the equal-signal zones of the localizer and glide path beacons, but indicates to him what roll and pitch angles must be maintained to accurately enter and follow the equal-signal zones.

The director control system simplifies piloting by converting navigation and flight information about the aircraft's position in space and forming it into a control signal, which is displayed on the command instruments. The deviation of the command arrow is a function of several parameters, which in a normal landing approach the pilot takes into account using separate instruments: PSP-48 of the SP-50 system, attitude indicator, compass and variometer. Therefore, the command shooters are in the center of the scale not only when the aircraft is strictly in the equal-signal zones of the course and glide path, but also when the correct exit to the equal-signal zones is made.

On aircraft already in operation, simplified director control systems are installed, operating on the basis of existing on-board and ground equipment: localizer radio KRP-F, glide slope radio receiver GRP-2, navigation indicator NI-50BM or heading setter ZK-2B, central gyrovertical TsGV or gyro sensors (AGD, PPS). In addition, the kit includes: a computer, a communication unit with the autopilot if there is a connection with the AP on the aircraft.

The landing maneuver on an aircraft equipped with a director control system is performed as follows:

1. Having received permission to enter the area of ​​an airport equipped with an SP-50 or ILS system, the crew, acting in accordance with the scheme approved for this airport, takes the aircraft to the place where the fourth turn begins; in this case, the crew is obliged to:

• a) on the NI-50BM heading machine, set the map angle equal to the landing MPU for a given landing direction;
• b) on the NI-50BM wind controller, set the wind speed to zero;
• c) before turning on the power on the M-50 panel, make sure that the heading and glide path arrows of the null indicator are in the center of the scale, otherwise set them in the center using a mechanical corrector;
• d) set the “SP-50-ILS” switch to the position corresponding to the system used for the approach;
• e) install on the SP-50 control panel the corresponding channel for the operation of the course and glide slope beacons;
• f) turn on the power on the M-50 panel;
• g) turn on the power on the director system control panel;
• h) make sure that the control gear and hydraulic control unit are working properly by deflecting the arrows of the null indicators and closing the blankers on their scales (blenders close after warming up the receiver lamps and in the presence of signals from ground beacons);
• i) during the landing approach in the area between the third and fourth turns with the blankers closed, check the electrical balancing of the heading bar zero by turning the balance knob on the M-50 panel in one direction or another until the arrow reaches the center of the scale. The check should be carried out after the aircraft enters the straight line.

2. The moment of the beginning of the fourth reversal can be determined:

• a) with the help of the ARC for the CSD DPRM;
• b) according to the azimuth and range of the angular-rangefinder system “Vode”;
• c) at the command of a dispatcher monitoring the aircraft using a ground-based radar;
• d) by on-board radar;
• e) by off-scale the course bar of the command device.

3. At the moment of the beginning of the fourth turn, create such a roll on the side of the directional bar of the command device that it will be set to scale zero. During the turn, the pilot must keep the zero indicator needle in the center of the scale, decreasing or increasing the bank. The roll is always created in the direction of the arrow deviation.

In the case of an early start of the fourth turn, in order to keep the directional needle in the zero position, it will initially be necessary to create a bank of 17-20°, which subsequently must be reduced in some cases until the aircraft is completely taken out of the bank. However, when approaching the runway alignment, the directional arrow of the command device will indicate the need to create the roll required to smoothly fit into the landing line.

With a late start of the fourth turn, the course changes by an angle greater than 90°, and the sign of the roll changes. In this case, the entire maneuver, including taking into account the drift angle, is processed automatically by the system.

When performing the fourth reversal, you must constantly ensure that the course blankers are closed on all zero indicators.

4. After completing the fourth turn and entering the equal-signal heading zone, you should continue the flight without descending, keeping the directional needle of the command instrument in the center of the scale with your rolls. At

In this case, it is necessary to monitor the glide path arrow, which will be deflected upward after the fourth turn. The glide path blankers must be closed.

As soon as the command instrument needle approaches the white circle, immediately begin descending, keeping the glide path director needle in the center of the black circle.

5. Based on the flight altitude of the DPRM, determine the possibility of continuing the descent along the glide path: if above the DPRM, when the glide slope arrow is within the white circle, the flight altitude is equal to or exceeds that established for a given airport, then further descent along the glide path can be continued; If, when maintaining the glide path correctly, the aircraft reached the established flight altitude of the DPRM and there were no signals of its actual passage, then immediately stop descending along the glide path and subsequently, after passing the DPRM, the descent is carried out according to the rules established for the OSP system.

6. After passing the DPRM, keep the directional arrows of the command zero indicator in the zero position, while not allowing a descent out of ground visibility below the weather minimum established for a given airport.

When the ground (landing lights) is detected, it is necessary to switch to visual flight and land.

Errors in setting the heading on the NI-50BM automatic machine, exceeding 15° in total with the drift angle, will not allow an approach to be made using the director control system at all. To avoid this, before starting the fourth turn, the navigator must again make sure that the “Map Angle” is set correctly on the NI-50BM heading machine and that the heading system is working correctly. When the magnetic heading readings are significantly greater than the actual heading on the landing line, the aircraft will deviate to the right from the axis of the localizer equal-signal zone, and when the readings are too low, to the left. To ensure good accuracy of the system on the landing line at large drift angles, the navigator must ensure that the heading system operates with high accuracy; the error should not exceed ±2°.

In addition, the accuracy of the aircraft entering the runway axis and following along it also depends on the accuracy of the localizer zone and setting the directional arrow to zero by turning the button on the SP-50 control panel.