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 landing approach system at large and busy airfields. In addition, it is the most accurate, unless, of course, you count the 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 pretend to be the most complete and only correct guide :), but as a tutorial at the initial stage, it will help you a lot.

The composition and principle of operation of the KGS

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

So, what does the KGS consist of:

1. Localizer, which provides guidance to the aircraft in a horizontal plane - on the course.
2. Glide path beacon providing guidance in the vertical plane - along the glide path.
3. Markers signaling the moment of passage of certain points on the approach trajectory. Typically, markers are set on the LPRM and BPRM.
4. Receiving devices on board the aircraft that provide signal reception and processing.

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

Now about how these beacons work. Let's take a localizer as a basis and consider its operation in a somewhat simplified way. During operation, the beacon generates 2 different-frequency signals, which can be schematically shown as 2 petals directed along the landing approach trajectory.

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

The glide path beacon works exactly according to the same principle, only in a vertical plane.

Reading instrument readings

So, we entered the zone of action of the KGS. The bars on the TNG went off scale, so it's time for us to find out where we are and how we need to pilot the plane in order to fit exactly into the trajectory of approach.

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

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 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 indication of the device in the positions indicated in the general figure.

1. We are on the course line and have not yet reached the glide slope 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 over us and rushes to nowhere at an angle of 2 degrees 40 minutes on average relative to the horizon. By the way, the angle of inclination of the glide path (UNG) is different at different airfields. It depends on the terrain and other conditions. For example, at mountain airfields, the UNG can be up to 4-5 degrees.

2. We are at the Glide Path Entry Point (GWP). This is the point formed by the intersection of the glide slope with the height of the circle. The average TG distance is about 12 km. Naturally, the higher the height of the circle and the smaller the LL, the farther from the threshold of the runway is the TVG.

3. We are to the left and above. It is necessary to turn right and increase the rate of descent.

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

5. We are to the right and above. Let's rotate to the left and increase the vertical.

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.

Consider that the closer we are to the runway, the less evolution of the aircraft must be, because the instrument becomes very sensitive. For example, if we are at a distance of 10 km from the threshold of the runway, the position of the heading bar on the second point of the scale may mean a lateral deviation of 400 meters or more (this is an example). To turn, we 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 allowable, and the only thing left for us is to go to the second circle. The closer the aircraft is to the runway threshold, the closer to the center the heading should be. Ideally, of course, exactly in the center :) And accordingly, the closer we are, the less evolution of the aircraft should be. It makes no sense to lay a 30-degree roll in the near drive area. Firstly, it is dangerous at such a height, and secondly, you simply will not have time to turn it around, given the inertia of the aircraft.

Approach- one of the final stages of an aircraft flight immediately preceding landing. Provides the launch of the aircraft on the trajectory, which is landing straight leading to the landing point.

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

glide path(fr. glissade- "slip") - the flight path of the aircraft, along which it descends immediately before landing. As a result of glide path flight, the aircraft enters the landing zone on the runway.

In paragliding, the basic glide slope is the direct path immediately before landing.

Glide slope angle - the angle between the plane of the glide path 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 magnitude of the glide slope angle can be affected by the presence of obstacles in the airfield area.

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

Also, the glide path is sometimes called the process of lowering the aircraft before landing.

Compared to other types of aircraft, the aircraft has the longest take-off phase and the most difficult in terms of organization of control. The take-off starts from the moment you start moving along the runway for the takeoff run and ends at the height of the transition.

Takeoff is considered one of the most difficult and dangerous stages of flight: during takeoff, engines operating under conditions of maximum thermal and mechanical loading may fail, the aircraft (relative to other phases of flight) is filled with fuel to the maximum, and the flight altitude is still low. The biggest disaster in the history of aviation occurred on takeoff.

Specific take-off procedures for each type of aircraft are described in the aircraft flight manual. Adjustments may be made by output circuits, special conditions (eg noise reduction rules), however, there are some general rules.

For acceleration, the engines are usually set to takeoff. This is an emergency mode, the duration of the flight on it is limited to a few minutes. Sometimes (if the length of the strip 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 terminated and the aircraft will stop within the runway. The calculation of V 1 takes into account many factors, such as: the length of the runway, its condition, coverage, height above sea level, weather conditions (wind, temperature), aircraft loading, balance, and others. In the event that the failure occurred at a speed greater than V 1 , the only solution would be to continue the takeoff and then land. Most types of civil aviation aircraft are designed so that, even if one of the engines fails on takeoff, the power of the others is enough to, after accelerating the car to a safe speed, rise to the minimum height from which you can enter the glide path and land the aircraft.

Before takeoff, the pilot extends the flaps and slats to the calculated position in order to increase the lift force, and at the same time, minimally impede the acceleration of the aircraft. Then, after waiting for the permission of the air traffic controller, the pilot sets the takeoff mode to the engines and releases the wheel brakes, the aircraft starts the takeoff run. During the takeoff run, the main task of the pilot is to keep the car strictly along the axis, preventing its lateral displacement. This is especially important in windy conditions. Up to a certain speed, the aerodynamic rudder is ineffective and taxiing occurs by braking one of the main landing gear. After reaching the speed at which the rudder becomes effective, control is made by the rudder. The nose landing gear on the takeoff 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 over the helm, increasing the angle of attack. The nose of the aircraft rises ("Lift"), and then the entire aircraft lifts off the ground.

Immediately after takeoff, to reduce drag (at a height of at least 5 meters), the landing gear is removed, and (if any) exhaust lights, then the wing mechanization is gradually removed. Gradual cleaning is due to the need to slowly reduce the lift of the wing. With the rapid removal of mechanization, the aircraft can give a dangerous drawdown. In winter, when the plane flies into relatively warm air layers, where the efficiency of the engines 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 mechanizing the wing is strictly regulated in the RLE for each type of aircraft.

Once the transition height is reached, the pilot sets the standard pressure to 760 mmHg. Art. Airports are located at different heights, and air transport is controlled in a single system, therefore, at the transition altitude, the pilot must switch from the altitude reference system from the runway level (or sea level) to the flight level (conditional height). Also, at the height of the transition, the engines are set to the nominal mode. After that, the take-off stage is considered completed, and the next flight stage begins: climb.

There are several types of aircraft takeoff.

• Takeoff with brakes. The engines are brought to the 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 run begins.
• Takeoff with a short stop on the runway. The crew does not wait until the engines reach the required mode, but immediately starts the takeoff run (the engines must reach the required power up to a certain speed). In this case, the length of the takeoff increases.
• Takeoff without stopping rolling start), "on the go". The engines enter the desired mode in the process of taxiing out from the taxiway to the runway, it is used at high intensity of flights at the airfield.
• Takeoff with the use of special means. Most often, this is a takeoff from the deck of an aircraft carrier in conditions of a limited runway length. In such cases, a short run is compensated by springboards, ejection devices, additional solid rocket motors, automatic landing gear wheel holders, etc.
• Takeoff of an aircraft with a vertical or short takeoff. For example, Yak-38.
• Takeoff from the surface of the water.

glissade- "slip") - a vertical projection of the flight path of the aircraft, along which it descends immediately before landing. As a result of glide path flight, the aircraft enters the landing zone on the runway.

In paragliding, the basic glide slope is the direct path immediately before landing.

Glide path angle- the angle between the plane of the glide path 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 magnitude of the glide slope angle can be affected by the presence of obstacles in the airfield area.

In the Soviet Union, the typical glide path angle was 2°40′. The International Civil Aviation Organization recommends a glide path angle of 3° (Appendix 10 to the Chicago Convention of 1944, Volume 1, Recommendation 3.1.5.1.2.1).

see also

Sources

• Big Encyclopedic Dictionary: [A - Z] / Ch. ed. A. M. Prokhorov.- 1st ed. - M .: Great Russian Encyclopedia, 1991. - ISBN 5-85270-160-2; 2nd ed., revised. and additional- M .: Great Russian Encyclopedia; SPb. : Norint, 1997. - S. 1408. - ISBN 5-7711-0004-8.

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An excerpt characterizing Glissad

Denisov frowned even more.
“Squeeg,” he said, throwing a purse with several gold pieces. “Gostov, count, my dear, how much is left there, but put the purse under the pillow,” he said and went out to the sergeant-major.
Rostov took the money and, mechanically, putting aside and leveling heaps of old and new gold, began to count them.
- BUT! Telyanin! Zdog "ovo! Inflate me all at once" ah! Denisov's voice was heard from another room.
- Who? At Bykov's, at the rat's? ... I knew, - said another thin voice, and after that Lieutenant Telyanin, a small officer of the same squadron, entered the room.
Rostov threw a purse under the pillow and shook the small, damp hand extended to him. Telyanin was transferred from the guard before the campaign for something. He behaved very well in the regiment; but they did not like him, and in particular Rostov could neither overcome nor hide his unreasonable disgust for this officer.
- Well, young cavalryman, how does my Grachik serve you? - he asked. (Grachik was a riding horse, a tack, sold by Telyanin to Rostov.)
The lieutenant never looked into the eyes of the person with whom he spoke; His eyes were constantly moving from one object to another.
- I saw you drove today ...
“Nothing, good horse,” answered Rostov, despite the fact that this horse, bought by him for 700 rubles, was not worth even half of this price. “I began to crouch on the left front ...” he added. - Cracked hoof! It's nothing. I will teach you, show you which rivet to put.

Flight practice on Tu-154 aircraft Vasily Ershov

In glidepath.

In glidepath.

Experienced pilots know that all mistakes, all rough landings, all rollouts are based on one decisive factor - the inability to keep the runway on target.

Pilot's inability to keep the director's arrow in the center all the time, neglect

the stability of the car's movement along the course, all sorts of theories on the "selection" of the course when using the director system, entering the course at the last stage - all this is a sign of a person's misunderstanding of a simple truth. It is impossible to solve the main task, constantly being distracted by an annoying trifle: “some” course.

It is impossible to ride a bike well by constantly comparing the side of your lean and the side and amount of handlebar deflection. Until you get a reflex.

This is the kind of reflex that a pilot should have on the director arrow. The position of the arrow not in the center should cause discomfort. The reaction to the deflection of the pointer must be automatic. A sense of alignment must be developed. Whoever has it always strives exactly to the axis; he always sits on the axle, and landing off the axle makes the professional feel inferior.

If the pilot solves the problem of keeping the course reflexively, then all his attention can be directed to the analysis of the behavior of the machine along the longitudinal channel. Such a pilot is more likely to solve this problem without errors.

The task of the aircraft movement along the glide path is to select such a thrust force that it is constantly equal to the drag force, which means that the speed is constant. When external forces are applied to the aircraft, the pilot must evaluate the effectiveness of their impact in terms of magnitude and time and either be able to wait out these disturbances, or - if they threaten to upset the balance of forces - change the flight parameters, returning to the original mode as soon as the disturbing forces disappear.

In practice, as we know, this is a continuous change in the pitch and thrust of the engines. And by the frequency of commands on the pre-landing straight, it is quite possible to judge the professionalism of the pilot.

Most often, the pilot, by his inability to pre-calculate the mode on the glide path, creates difficulties for himself. Figuratively speaking, it “flies behind the aircraft”, reacting to disturbances by changing the regime and pitching.

This style of piloting reminds me of an inexperienced driver driving through our Russian streets. I saw the hatch - I drove around, I saw the hatch - I drove around, I saw the hatch - I drove around ... Yes, stand in another row or something. No, he is reacting. Such control of the aircraft is still the same consumerism of movement, the same principle of "gas - brake".

So, we have a task: the constancy of the instrumental and vertical speeds. Their calculated values ​​are known: roughly, 270 and 4, respectively. How to build an analysis of the behavior of the car on the glide path, "from what to dance"?

"Dancing" from vertical speed. If it is stable, then the entry is stable. If the vertical is stable to the end, then the approach is ideal, the problem is solved, and it remains only to land.

If the vertical speed, while maintaining the glide path arrow in the center, began to increase, then either a tailwind component appeared, or the opposite one fell.

If such a phenomenon occurs after the LBM, then it is usually associated with a weakening of the wind near the ground. If it is at a height, then it should be remembered that a change was expected, maybe a wind shear.

In any case, an increase in vertical speed entails an increase in translational speed. But - only under the condition that the glide path is in the center, which means that the plane is moving along the hypotenuse, and all the laws of vector addition are in effect. If the increase in vertical speed is associated with suction under the glide path, then the director arrow will vigorously go up at the same pitch and at the same speed.

If a mistake is made and the pitch is reduced, then the aircraft will go under the glide path with an increase in both vertical and indicated speeds.

The pilot constantly analyzes the cause of the change in vertical speed. Either these are his technical errors, the buildup in pitch; either it is a change in the wind; or changes in temperature and air density that affect the amount of thrust in the same mode and the amount of lift at the same translational speed. In the latter case, the rise in vertical is the inevitable consequence of the pilot reducing the pitch angle in order to keep the glide path needle centered.

Either the pilot keeps the increased mode and accelerates the speed, and the aircraft tends to go above the glide path, and in order to keep it on the glide path, it is necessary to increase the vertical speed.

Having determined the cause of the change in vertical speed, the pilot must evaluate whether it is possible to return to the original flight mode only by deflecting the yoke if it was his technical error, or whether it is necessary to change the thrust of the engines if flight conditions have changed with altitude, or wait until the disturbance disappears, and wait until the machine, which is stable in speed, returns to its original mode on its own.

In any of these cases, it is necessary to operate the elevator as carefully as possible. Usually a sensitive pilot notices a tendency to change the vertical speed and strives to return it to the calculated value with a barely noticeable impulse in pitch, immediately returning the helm to its original position. Trimmer click there - click back. Actually, all piloting on the glide path, in addition to the automatically maintained course, is carried out precisely by maintaining the vertical speed. The director went up a little - the vertical immediately decreases. The director returned to the center - the calculated vertical line is immediately established. If the director strives to go up again and again, this is already a tendency: it is necessary to reduce the vertical speed; what is the reason?

All this analysis is carried out at a subconscious level and is expressed in the brain only by the feeling of the desire of the aircraft, or rather the pilot himself: “I went higher. I'm being pushed above the glide slope... by a travel companion? Big mode? Inversion? Strong counter gust?

Depending on the establishment of the cause, I either simply press down, or press and remove the regime, or hold and patiently wait: this impulse will fall, fall; let the speed increase, I will be patient, the speed will also fall ...

You can, of course, not think. Keep the director in the center and react to changes in speed: increased - remove the mode, fell - add.

If this does not take into account the vertical speed, and, usually, the pitch ranges accompanying its jumps, then, with the formal maintenance of the course and glide path, with a constant indicated speed, an off-design high vertical speed is still quite possible in front of the butt, the correction of which introduces an adjustment into glide path keeping, and the correction of the glide path keeping error can add up with an already not calculated vertical speed.

In the narrowing wedge of possible deviations - attention and subtlety of movements are no longer enough; if this still diverts attention to maintaining the course, the likelihood of a gross error increases.

The whole point of the analysis is to keep the vertical speed at which an 80-ton aircraft approaches the ground constant. In order to pay it off, simple steps are required. But if the vertical speed near the ground is unpredictable, then it is not possible to catch the moment when it is exactly calculated, and a relatively soft landing is a matter of chance.

These subtleties, of course, do not apply to simple flight conditions in which

an ordinary pilot is also able to withstand the parameters.

We fly in any, and even very difficult conditions, when all the strength of his will, all his talent, all his ability to control the situation is required from the captain - and, especially, the ability for subtle analysis in conditions of acute time pressure. And the more the captain is accustomed to analyze the situation, the finer his flair develops, the intuition that allows him to control the behavior of the machine on a subconscious level, and pay more attention to maintaining a calm, friendly atmosphere in the cockpit, in which the crew works relaxed and confident.

The specifics of our work is that we often have to fly in winter on northern airfields, where severe frosty inversions are not uncommon. The layer where the air temperature begins to drop sharply towards the ground lies somewhere at altitudes of 200-150m, and at this temperature boundary, wind shear is not uncommon, accompanied by turbulence and jumps in IAS.

I had to land in the conditions of a surface polar front, with strong winds, at temperatures below -30 °, and, without counting on a frosty inversion, I nevertheless got into conditions of transition from warmer to colder layers. just at an altitude of 150 meters - with a full set of all the troubles that accompany the inversion. Our RLE limits the reduction of the engine mode on the glide path below 200 m in wind shear conditions. Based on my experience and the experience of senior colleagues, I come to the conclusion that these restrictions, 72% and 75%, for "B" and "M", respectively, were introduced out of fear of a sharp loss of speed in conditions of downdrafts near a thundercloud. But it is unlikely that our aircraft was tested in conditions of frosty inversions for such a long time as we fly it under these conditions.

The restriction on the “not lower than 75%” mode for the “M” machine puts the crew in a frosty winter in difficult conditions. Sometimes on a light car in calm, the required mode even at the entrance to the glide path is already 78-76%. When approaching the ground, the air condenses so much that the 75% mode creates too much thrust, and the plane starts to accelerate. Reduce speed does not give a limit; increasing vertical speed only adds acceleration. On limited lanes, this leads to such a flight that it is better to go around.

If it is vital for the crew to land in such conditions, they must be aware of what is more important - the figure or the actual behavior of the machine. The number 75 is calculated for wind shear in summer heat and is quite real. In conditions of low temperatures, it is on the border of absurdity.

The aircraft in such conditions flies perfectly and at modes less than 75%, up to low gas as needed. Therefore, in order not to unbalance the balanced approach mode, it is necessary to set the mode that the conditions require. The only thing, in modes close to the idle mode, you need to carefully monitor the speed trend and add the mode in time before leveling, if a tendency to its fall is noticed.

In any case, landing at low temperatures requires a timely reduction in engine power, and the closer to the ground, the more energetically. Here the point is also that the headwind usually decreases towards the ground, which means that the ground speed increases, and some increase in vertical is required. A typical mistake of young pilots after a VPR is to go above the glide path, precisely for this reason. And the car must be pressed, which means that it is time to reduce the mode.

Trends must be anticipated. If the pilot, correcting, for example, the deviation from the glide path upwards, removed the mode and presses the car from above to the glide path, then you need to remember about the removed mode and add this mode in advance, before reaching the glide path, because on the glide path the vertical speed will be required less than the one with which the car is now catching up with the glide path.

It is unlikely that a flight engineer should be required on a heavy aircraft

perform the functions of an autothrottle. Without instruments at his disposal to show the deviation of the machine from the trajectory, the flight engineer will always lag behind in his response only to changes in speed.

The same applies to the use of a very imperfect autothrottle. I have not used it since the Shilak disaster and do not recommend it to others. He is not able to respond to speed changes by changing the mode within 1-2%, he not only does not participate in the analysis of the behavior of the machine, but, on the contrary, introduces dissonance and confuses the thinking pilot. But for consumers bypassing hatches on the road - please. On a mark of "3" he is an assistant.

About portions of the regime. RLE gives too broad standards. I always use one percent. Of course, in a strong chatter (to put it more precisely, in a “strong chatter”) you have to use large portions, but if possible I still try to endure and catch the main trend among the speed jumps, forestalling it with the same one percent.

We must always remember that 1% of the regime is tons of thrust. The range from 70 to 95% in flight includes thrust from 500 kg to 10 tons. Count yourself. If I allow myself to periodically apply and immediately remove 5 tons of thrust on the glide path, I will never achieve a rectilinear uniform movement.

The same goes for the course. Watching from the side how the young pilot turns the steering wheel, how he, all in business, corrects non-existent deviations - I suggest that he give up control. Does it fly by itself? And after all, it flies by itself, if it is streamed. By the way, this should become a rule for both young and experienced pilots. Quit, make sure: am I too constrained? Am I holding the steering wheel?

But the closer to the ground, the narrower the wedge, or rather, the cone of deviations, the more precise, smaller, more timely the movements should be, the sharper the reaction should be - and the more stable the plane should fly.

An approach using the OSB system on a heavy aircraft requires strict adherence to the design parameters, which is possible only with the well-coordinated work of the entire crew. There is no course and glide path control, but there is only an approximate direction and an approximate, with a margin, vertical speed. Well, if there is a control for deletion; it is good if a simple direction finder is used. The course is easier to maintain using the ACS in the "ZK" mode. At the same time, one should always remember about one feature of the drive approach. The exit angle should always be taken half as much as it seems; the exit time is also taken half as much as desired. Make no mistake.

Having studied at one time on the piston IL-14, I had plenty of time to observe the OSP visits of my fellow listeners, being constantly behind them in a spacious, not like the current cockpit. And here I realized that the pilot (and me too) has an inherent desire to get on the course faster and more abruptly. And I saw what comes out of these attempts. The plane has already entered the landing course and continues to follow with an exit angle already beyond the position line, but the ARC is still late and cannot convincingly show that you are already on the other side. And when it shows, it is necessary to take the exit angle in the other direction; and as a result, the entry is obtained along a sinusoid, and the DPRM always remains on the sidelines.

The closer to the far drive, the smaller exit angles you need to take and the less time you need to go with these angles. Approaching the far one, it is necessary to switch all attention to the near one and take a course on it in advance, without trying to pass the DPRM exactly. By the time the VPR is reached, and this is between the far and the near, the heading should be close to the landing one, and the KUR should be close to 0o, of course, taking into account the drift.

As for the control of the longitudinal channel, the peculiarity here is that the approach method itself requires the vertical speed to be kept more than the calculated one, which means that the mode must be kept less.

After the passage of the DPRM, the vertical speed must be kept at the calculated one,

which means adding a mode in advance.

A common error when approaching along the OSB is the late start of the descent along the glide path and failure to maintain the calculated, i.e., 0.5–1 m / s more, vertical speed, which is fraught with the flight of the long-range drive by higher altitude and an increase in the vertical in the area where it must be kept already strictly calculated. Such a catch-up of the glide slope can continue to the very end, with the mode being lowered than the calculated one, and there is a danger of forgetting that the vertical speed is significant and it will be necessary to start leveling higher with a proactive addition of the mode. Whoever forgets about this in his passion to get strictly on the end and on the axis, he risks getting a decent overload on landing.

Up to a height of 150 meters, all parameters: heading, glide path, speed and vertical must be normal and stable. It happens that strong atmospheric disturbances throw the plane out of the glide path. Down is not as scary as up, and requires only a vigorous addition of the mode and a decrease in vertical speed with the restoration of parameters when approaching the glide path. If it kicks up, then there is no time to waste. An experienced pilot, by smoothly but energetically lowering the nose, with simultaneous cleaning of the regime, can catch up with the glide path in one movement, increasing the vertical speed to 7 m / s once, but in advance, even before approaching the glide path, he will add the regime to the calculated one and in advance, to the glide path, will decrease the vertical to the calculated value. It is desirable to complete this operation before a height of 150 meters in order to stabilize the parameters.

An inexperienced pilot will miss the time and start to catch up with the glide path at a slow pace and with a slight cleaning of the regime, accelerate the speed, and if he catches up with the glide path, then he will have problems with high vertical and forward speeds on the VFR.

I describe this method of a one-time glide path catch-up, only to show that the aircraft willingly loses altitude without having time to accelerate forward speed, but it requires significant efforts to then reduce the descent, which means meaningful, proactive actions by the captain. And if this method can, within certain limits, be used in the area of ​​the DPRM, then it is categorically impossible below the VPR, which will be discussed in detail below.

Regardless of the choice of the approach system, the navigator is obliged to constantly control the direction by the drives, starting from the beginning of the fourth turn - and until the flight of the BRM. There were cases of failure of the localizer or the course equipment of the aircraft, and the control of the OSB saved.

It is also mandatory for the navigator to control the height of the distance. The right triangle must be maintained. At the command "No further!" the captain is obliged to immediately bring the car into level flight with the setting of the mode, which is 4-5 percent higher than the design mode on the glide path.

Due to the appearance of a large number of radio equipment in passengers, which can affect the operation of on-board systems on the glide path, the aircraft may smoothly deviate from the established trajectory without triggering a warning alarm. The author of these lines had the opportunity to see how, with externally working systems, the vertical speed began to increase smoothly, and the director arrows stood in the center. And only the warning of the navigator "there is no further" and the exit to the visual flight prevented the further development of the situation.

Tu-154 operation experience has shown that crews have learned to hold 10-15 km/h more recommended flight speeds on the glide path (especially at low landing weights). Of course, flying at a higher speed is somehow calmer, more guaranteed, but we must not forget that the landing parameters are calculated depending on this particular speed - the speed of crossing the butt. Therefore, it is desirable to cross the butt at the speed recommended by the Flight Manual, that is, exactly corresponding to the actual landing weight. On the glide path, let the speed be a little higher, this guarantees controllability in a possible bumpiness, but after the VPR, the speed must be gradually reduced, and in other situations - and quite vigorously. One of the common mistakes of young pilots is that once they pick up the speed, they tend to keep it until the very alignment, forgetting that at low altitudes the wind weakens and an increase in vertical speed is required, albeit slightly, but accelerating forward speed, and therefore requiring a reduction in mode.

The only time you need to keep the speed high is when landing in conditions of heavy icing and with a strong side wind. But in 20 years of flying the Tu-154, I never got into heavy icing, and I didn’t see that the icing, which sometimes I have to get into, somehow affected the landing. However, the experience of old pilots who had to land on piston aircraft, adding the mode on the glide path to the nominal and even higher - there was such a strong icing - says that if you really have to, God forbid, get into such conditions on the Tu-154, for example, in the waiting area, then you need to take them seriously. Here it must be remembered that such ice, in addition to disrupting aerodynamics, also significantly increases the mass, and therefore, coupled with an increase in speed, and kinetic energy, which can be extinguished on the run only by resolutely applying reverse to a complete stop.

As for landing with a crosswind, attention will be paid to it below.

Maintaining glide path speed in thermal turbulence requires only patience. Typically, such conditions occur in light winds, and the analysis of the behavior of the machine on the glide path is easier. Sometimes deviations from the recommended speed are significant, but they are short-lived and do not require a mode change when the pilot slows down. It is much more difficult here to maintain the recommended vertical speed and glide path.

It is better to go into a strong turbulence in automatic mode, with the “in turbulence” toggle switch turned on, not forgetting to set the IN-3 bar to the neutral position with the aileron trim switch so that when the autopilot is turned off, there is no desire to roll the aircraft. The stability-handling system copes well with the bumpiness, and the pilot saves strength for the last 20 seconds.

In general, descent from the flight level in the helm control mode, manual entry and landing are quite laborious, and sometimes they take so much strength that there are almost none left by the time of flight. Personally, I never manually descend, and, moreover, I never force young co-pilots to do it. At the same time, instead of thoughtful analysis, they are engaged in the fight against iron. To those who prove that once it will come in handy, I will answer: how many times did it come in handy for you? To me, never. And these trainings should be left for light aviation. You don't have to drive nails in with a computer. Iron should work for the hands of the pilot, and the brain should control the iron. In order to play the huge organ, it is not at all necessary to pump air into the pipes with bellows.

I am talking here about the high art of flying a heavy airliner. We are the aviation elite. We are masters. And the worker-peasant approach to this art is inappropriate.

So, on a glide path, a normal pilot must be able to maintain the director arrows within the circle and correct pitch disturbances, not allowing the glide path to deviate more than a point, with an immediate return to the original mode, or with a steady tendency to return to it. In this case, the vertical speed is the basic parameter for analysis, and the instrumental one is an indicator of the tendency to change the vertical. The instruments are pitch and engine mode.

Maybe one of my colleagues will chuckle: well, heaped up ... yes, that's all

it's much easier, hands do it themselves ...

If you have such a talent - yes to health, and God forbid your hands to keep their skills until retirement. I can't do this. I have neither such a reaction, nor such a flair, so that with one movement at once - and in kings. It's only in the movies that everything works out the first time. I have behind me a huge, scrupulous work on myself, a lot of failures and a constant feeling of dissatisfaction. And every old pilot is like that.

Although there are examples when the old captain is let down by flair and acumen. Example

Ivanovo catastrophe should constantly cool other hotheads.

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ILS landing

Heading Glide System (ILS)

Landing visually in good visibility is easy and pleasant, but, unfortunately, the weather does not always allow this. Aviators began to look for a solution to the problem.

Already in 1929, testing of a radio navigation system began, which allows landing with instruments out of sight of the runway, and in 1941, the use of such a system was authorized by the American aviation administration at six airfields in the country.

First instrument landing passenger liner performing a regular flight was made on January 26, 1938. A Boeing 747 flying from Washington to Pittsburgh landed in a blizzard using only a course-glide path system.

The course-glide path system (KGS) is designed for landing in conditions of lack of visibility of the runway. In English, this system is called the Instrument Landing System, abbreviated as ILS. ILS consists of two main independent parts: course (localizer) and glideslope (glideslope) beacons.

Localizer, as the name implies, allows you to control the position of the aircraft on the course. The localizer is located at the opposite end of the strip and consists of two directional transmitters oriented along the strip at slightly different angles, transmitting a signal modulated at different frequencies. In the middle of the strip, the intensity of both signals is maximum, while to the left and right of the strip, the intensity of one of the transmitters is higher. The receiving equipment compares both signals and, based on their intensity, calculates how much to the left or right of the center line the aircraft is.

Localizer is abbreviated as LOC in America, or LLZ in Europe. The carrier frequency is usually between 108.000 MHz and 111.975 MHz. Modern localizers are usually highly directional. Older beacons were not, and their signals could be picked up on the return course. This made it possible to make an inaccurate approach to the opposite end of the runway if it was not equipped with its own ILS. The big disadvantage of such an approach is that the device will show a deviation from the course in the opposite direction, which greatly complicates the approach.

A glide path (glideslope or glidepath, abbreviated as GP) works in a similar way. It is installed on the side of the strip in the landing zone:

The carrier frequency of a glide path is typically between 329.15 and 335 MHz. Fortunately, the pilot does not need to enter the frequency of the glide path beacon separately, the device tunes to it automatically.

The glide path angle (GPA) may vary depending on the surrounding terrain. The standard glide slope angle abroad is three degrees. In Russia, an angle of 2 degrees 40 minutes is considered standard.

In addition to the main components, the ILS may include a number of additional ones. These components are marker beacons. They are radio beacons that radiate a narrowly directed upward signal at a frequency of 75 MHz. When an aircraft passes over such a radio beacon, the equipment receives it and lights up the corresponding indicator. The pilot, looking at the indicator, must make a decision corresponding to the beacon.

There are three types of marker beacons:

1. Far marker beacon (Outer Marker, OM). Typically located at a distance of 7.2 km from the threshold, but this distance may vary. When passing over the beacon, the letter O in the cockpit lights up and flashes. At this moment, the pilot must make a decision to approach using the ILS.

2. Middle marker beacon (Middle Marker, MM). Located about a kilometer from the threshold of the runway, in the cockpit it is indicated by an indicator with the letter M. When approaching on ILS category I, if at that moment there is no visibility of the ground, the pilot must initiate a go-around.

3. Internal marker beacon (Inner Marker, IM). Usually located about 30 meters from the threshold of the runway, beech I lights up during the passage. During the approach on ILS category II, if there is no visibility of the ground at the time of the passage of the beacon, you should immediately start a go-around.

In practice, not all marker beacons can be installed at the same time. The internal beacon is very often missing. Often marker beacons are combined with driving radio stations.

Together with the ILS, an omnidirectional rangefinding radio beacon, or RMD (in English DME, Distance Measuring Equipment), can work. If DME is installed, the DME in the cockpit indicates the distance to the end of the runway. Sometimes DME can be used instead of marker beacons. In such cases, the landing charts may state that the use of DME is mandatory for ILS landings.

ILS are divided into categories that define the minimum weather in which they can be used. There are three categories of ILS, denoted by Roman numerals. The third category, in turn, is divided into three subtypes, denoted by Latin letters. The table below lists the features of all ILS categories:

ILS categories impose requirements not only on ILS equipment, but also on aircraft equipment. For example, when using category I in an aircraft, it is sufficient to have a conventional barometric altimeter, and when using higher categories, a radio altimeter becomes mandatory.

Special equipment monitors the correct operation of the ILS. In the event of a malfunction, the ILS should automatically turn off. The higher the ILS category, the less time it should take to troubleshoot and disable the ILS. So, if a category I ILS must turn off within 10 seconds, then for category III the turn-off time is less than two seconds.

A pilot who is about to land on an ILS should first familiarize himself with the landing pattern. A typical ILS landing pattern is as follows:

The circuits are explained in detail in a separate article, but for now we are only interested in the ILS frequency:

This diagram shows that the ILS frequency is 110.70, and also shows the DME frequency, the location of the markers and the missed approach pattern.

To work with the ILS, the same set of equipment is used that works with the VOR. On the instrument panel, receivers are usually labeled NAV 1 and NAV 2 if a second set is installed. Use the double knob to enter the frequency into the receiver. Most of it is used to enter integers, smaller fractional parts of the frequency. The figure below shows a typical radio navigation instrument control panel:

The receivers are labeled in red. This is the simplest type of receiver that allows you to enter only one frequency. More complex systems allow you to enter two frequencies at once, and quickly switch between them. One frequency is inactive (STAND BY), it is changed by the frequency selector knob. The second frequency is called active (ACTIVE), this is the frequency to which the receiver is currently tuned.

The figure above shows an example of a receiver with two frequency references. It is very easy to use: use the dial to enter the desired frequency, and then make it active using the switch. When you hover the mouse over the selector wheel, the mouse cursor changes shape. If it looks like a small arrow, then when you click on the mouse, tenths will change. If the arrow is large, then the integer part of the number will change.

There should also be a device in the cockpit showing how far from the course and glide path the aircraft is currently located. This device is usually called NAV 1, or VOR 1. As we have already found out, an aircraft may have a second such device. There are two of them in the Cessna 172 aircraft:

The device consists of a movable scale resembling a compass scale, a round OBS setpoint knob (not used for working with ILS), a TOFROM direction indicator arrow, a GS banner and two bars, vertical and horizontal. The vertical bar shows the deviation from the course, the horizontal deviation from the glide path. The GS banner disappears after receiving a glide slope signal.

Enter the ILS frequency into the NAV 1 receiver and observe the instrument. Suppose the aircraft is exactly on the glide path and on the course:

As you can see from the picture, in this case the NAV1 bars are exactly in the center. This is the ideal position to which one should always strive. In practice, it is very easy to deviate in any direction. If the aircraft deviates below the glide path, the vertical bar will deviate upwards:

In this case, you need to pull the steering wheel towards you (or increase the engine speed) and return to the glide slope. Now suppose that our plane is exactly on the glide path, but deviated from the course to the left:

This time the bar deviated to the right, which means that you need to turn right and go on course. The rule when flying on ILS is the same as when flying on VOR: you must fly in the direction that the bar shows. Where the bar deviated, the plane must be directed there. As a rule, both bars will deviate at the same time:

Here the plane deviated up the glide path and to the right on the course. The pilot needs to descend lower to reach the glide path and turn right to return to course.

In aircraft equipped with elevator trim, it is easiest to trim the aircraft down so that it itself remains on the glide path. At first it will not be easy, but with the advent of experience, everything will start to turn out. Once the aircraft is trimmed correctly for descent, all that remains is to slightly correct it and follow the heading bar.

To correct the vertical speed, you can use the engine control knob: an increase in engine speed will slow down the descent, a decrease, on the contrary, will increase the rate of descent.

In difficult weather conditions, one must not forget to control the position of the aircraft in space using the artificial horizon, and always monitor the speed. The speed with which it is necessary to land is written in the flight manual of the aircraft.

Now, all that is left for the successful use of ILS is to start mastering it in practice. You can start with the VOR/ILS simulator located at http://www.luizmonteiro.com/Learning_VOR_Sim.htm . If you switch it to LOC Glide Slope (ILS) mode, it will begin simulating ILS operation. By moving the aircraft in the horizontal and vertical planes with the mouse, you can get used to the behavior of the heading and glide slope bars.

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