Basic Instrument Flying

 

Before starting with the instrument flying instruction, study or review PILOT NOTES VII, VIII and IX, respectively covering the magnetic compass, the pressure instruments and the gyroscopic instruments, and answer the associated questionaries in writing.   

 

As there is no fundamental difference between flying on instruments and flying with outside references, it is strongly recommended that you also review the very basics of flying, such as the primary and secondary effects of flight controls, propeller effects, slow flying, turns, etc., before starting with the basic I.F. training (see ELEMENTARY FLIGHT TRAINING MANUAL).      

 

The subsequent lessons related to basic I.F. and basic radionavigation are conducted partly in the simulator, partly in actual flight.   

 

As far as the simulator-is concerned, it is recommended that you spend some time in it while it is inoperative before your first lesson, just to acquaint yourself with the panel's layout, the graduations of the various instruments and the location and use of the various switches and levers.    

 

You will notice that the simulator shows a close resemblance with a light aircraft cockpit: control wheel, rudder pedals, all the necessary instruments, navaids, switches and levers, are available. It can often be programmed either as an aircraft with fixed pitch or with constant speed propeller. Some can even be programmed to represent either single or multi-engined aircraft. You may as well find additional equipment unknown to you so far, for instance cowl flaps: don't worry about that, it will be explained to you in due time if necessary.

 

Light aircraft simulators, unlike the very sophisticated systems used for airliners which can move by means of hydraulic jacks and thus produce sensations of acceleration and deceleration are mostly fixed installations. Nonetheless, they are often fitted with a visual system allowing to use "external" references, and able to simulate day or night operations with various levels of ceiling and visibility. Modern light aircraft simulators offer a number of additional possibilities in order to imitate real operations very closely: the instructor has a computer at his disposal which allows him to program the simulator for the aircraft in use, specific airports with their associated departure and arrival procedures, as well as to insert wind directions and velocities, failures of all kind, or other events such as turbulence, icing, etc.

 

The simulator is usually connected to a so-called plotter table or panel fitted with a pen system, on which the various routes appear as they are flown by the student during the training session. 

 

The simulator must be considered as a training aid, preferably to be used in parallel with the flight sessions. The reason for using a simulator is that it is a lot less expensive than the aircraft and that, as such, it reduces the training costs. Furthermore, it allows to repeat any specific exercise as many times as necessary with a minimum of time loss. Finally, the instructor can "freeze" the simulator instantly at any moment, thus allowing the student to clearly see and correct his mistakes.     

 

The simulator provides its utmost efficiency when, besides being used in parallel with the flight lessons, both the simulator and the flight training are provided by the same instructor, or by separate instructors using exactly the same methods and the same techniques.  

 

The simulator will not be used to the full extend of its possibilities at this stage of your training. However it will be used again, once you will have acquired same experience in actual flight, and that you will engage in IFR training. Even when you will be a fully qualified IFR pilot, regular simulator sessions will be strongly recommended to constantly improve your proficiency and safety level.          

 

Remember that the simulator is only the imitation of an aircraft. Its flight controls react to electronic signals induced by the use of the control wheel and rudder rather than to actual airflow and, because of this, it may feel somewhat different, often more sensitive, as compared to the real aircraft. Although this may be experienced as an additional difficulty at first, you will soon realize that, as is the case in actual flight, holding the flight controls lightly (two fingers on the control wheel and tip of the feet on the rudder pedals) is a must which will simplify things considerably.      

 

Let us now go ahead with the first lesson!         

 

Happy landings!      

 

 

 

 

A) BRIEFING

This very first simulator session consists initially of a closer acquaintance with the machine. You will go through the before starting and starting procedures, just like in the aircraft, following the appropriate checklists of which you will find a copy "on board", or you can use the same checklist as in the aircraft.           

 

Present day light aircraft simulators usually do not provide for taxiing, and you will find yourself lined up in the beginning of the runway (unless your instructor judges it more appropriate to put you directly in flight conditions). At this stage you might perform the engine run-up, but this may be neglected in the simulator to avoid loss of time: simply go through the before takeoff checklist after having started the engine and, with the knowledge of the rotation speed and the initial climb speed which the instructor will have specified, you are all set for a "visual" takeoff.    

 

During the first few minutes after takeoff, your instructor will let you free to handle the simulator just to get the feel of it. Take this opportunity to actuate the ailerons, the rudder and the elevator separately to observe the reactions of the simulator, try a few turns, climbs and descents, etc.

 

After a while the session will settle to its actual purpose: cruise flight. Let us first go through some basic I.F. principles which are to be reviewed again and again as the subsequent lessons progress:

 

1°) As said earlier, there is no fundamental difference in aircraft handling between flying on instruments and flying with outside references. However, flying on instruments enhances precision because any minor control or power input will show almost immediately on the related instruments while¡ when using solely outside references the resulting effects may go undetected for a few moments. Therefore, the pilot practicing instrument flying on a regular basis will usually be much sharper than his colleague who is not familiar with this technique. 

 

2°) Instrument flying demands a sustained concentration on the part of the pilot and, because of this, it can be very exhausting in the early stages of training. However, after a while, this concentration effort becomes a sort of second nature and will be sustained almost unknowingly.       

 

3°) After some practice, you should be able to control the aircraft within ± 100 ft of the required altitude, ± 10 kts of the required speed, and ± 10° of the required heading. Keep in mind that these values are maximum allowable deviations and that the pilot must always revert to the exact target value as quickly and as smoothly as possible. 

 

4°) You must develop a quick scanning technique of all basic instruments, i.e. the altimeter, the vertical speed indicator, the airspeed indicator, the turn indicator, the D.G., as well as the engine power instruments, all of which are to be related to the attitude indicator. Once radionavigation will be involved, the ADF, VOR, ILS and DME indicators will have to be included in this scanning. Any time the scanning reveals an undesired condition, even the slightest, it should be corrected at once, but in a smooth way, without jerks, referring mainly to the attitude indicator.    

 

5°) Regarding instrument scanning, staring at one specific instrument, whichever that instrument might be, must be banned at all costs. Keep also in mind the natural human disposition for peripheral vision: you can look at one specific instrument and, at the same time, register the indications of the surrounding ones, a very useful ability indeed.

 

6°) Still concerning instrument scanning, remember that besides the basic instruments (and the navaids), it is imperative to include the "secondary" instruments at regular intervals: oil pressure, oil temperature, CHT, EGT, fuel, ammeter, suction, etc.

 

7°) Before applying a corrective action, be sure to apply the correct one. This is a matter of interpretation of the instruments. For instance, assuming that the VSI reads an UP value and that the altimeter shows a gradual increase in altitude, the first action might be to decrease the pich attitude, whereas the real reason of this situation is perhaps an excessive power setting: hence again the need for rapid scanning. 

 

8°) Remember that if the aircraft is fitted with a fixed pitch propeller, nose up or down variations cause the rpm to respectively decrease or increase: here again a situation which might trigger the wrong corrective action by re-adjusting the power setting, whereas the pitch attitude is to be corrected.      

 

9°) Instrument flying demands, probably even more than when flying with outside references, a very light touch on the flight controls: keep the tips of the feet on the rudder pedals and let your feet rest comfortably on the floor to avoid unconscious pressures on the rudder. As for the control wheel, two fingers on it are sufficient (even in light to moderate turbulence). This will make the trimming requirements very conspicuous: once the trim(s) is (are) properly set, the aircraft flies practically by itself. Remember that, except during turns which are transient manoeuvres, or during short term corrections, any change of power setting, any change of flight configuration, or any change in pitch attitude must be accompanied by a re-adjustment of the elevator trim, using small inputs one way or another, until you can completely release the control wheel and that the aircraft maintains its new flight condition. In fact, a near constant interaction between the control wheel and minor inputs on the elevator trim is required throughout the flight.         

 

 

B) SIMULATOR TRAINING

 

You will now establish the simulator at normal cruise power at a specified altitude and heading, properly trimmed, and with "visual" still available. Note that "normal cruise power" in the simulator usually means a setting specified by the instructor. In the aircraft it refers to a specified percentage of power, usually 65%. In both cases the resulting airspeed is accepted as "normal" cruise speed. 

 

1°) Pay now attention to the attitude indicator: nose of the model aircraft on the horizon bar (if necessary adjust the attitude indicator by use of the trim knob), wings level, and note the associated following readings: 

 

- ASI: steady lAS     

- Altimeter: steady altitude 

- VSI: zero     

- D.G.: steady heading       

- Turn indicator: needle and ball centred           

 

2°) Notice also the pitch markings on the attitude indicator.   

 

3°) Pull very gently on the control wheel so as to put the model aircraft about one width above the horizon bar and to maintain it there. Notice the equivalent new attitude in relation to the "outside" reference. Next notice the following instrument readings:

 

- ASI: decreasing IAS         

- Altimeter: increasing altitude      

- VSI: up trend         

- D.G.: steady heading       

- Turn indicator: needle and ball centred           

 

4°) Depress now the control wheel until the model aircraft is again on the horizon bar and notice all parameters reverting to their previous value, except for the altimeter which now reads a somewhat higher altitude. 

 

5°) Depress now the control wheel further so as to put the model aircraft about one width below the horizon bar and maintain it there. Notice again the equivalent new attitude in relation to the "outside" reference, and notice the following instrument readings: 

 

- ASI: increasing lAS          

- Altimeter: decreasing altitude     

- VSI: DOWN trend 

- D.G.: steady heading       

- Turn indicator: needle and ball centred           

 

6°) Gently pull the control wheel until the model aircraft is again on the horizon bar and notice once more all parameters reverting to their previous value and the altimeter reading a somewhat lower altitude.          

 

Once in straight and level flight again, notice the bank markings and their associated value on the attitude indicator, usually 10°, 20°, 30°, 60° and 90°. Then proceed as follows:     

 

1°) Apply and maintain about 5° of bank to one side while maintaining the nose of the model aircraft on the horizon bar. Notice the following readings:     

 

- ASI: practically steady lAS          

- Altimeter: practically steady altitude      

- VSI: practically zero          

- D.G.: heading changing  

- Turn indicator: needle slightly deflected to the turn direction, ball practically centred          

 

2°) Level the wings again, notice the new heading, then repeat the experiment to the other side.   

 

The previous exercises will emphasize the need for very small control inputs to obtain a significant response. They give you an idea of the required inputs to perform the attitude and heading changes needed to correct minor altitude and heading deviations. Such small inputs produce very gradual corrections, referred to as "trends", towards the target altitude and heading values without causing noticeable speed variations. Any stronger inputs are likely to lead to overcontrol.

 

Assuming a fixed pitch propeller, pull the nose up to a somewhat steeper pitch attitude and watch the decreasing rpm. Conversely/depress the nose to a pitch down attitude and watch the increasing rpm. This experiment emphasizes that/ with a fixed pitch propeller/ when a change in rpm is noticed, it might call for a re-adjustment in pitch, and not necessarily for a power setting correction.         

 

The "visual" will now be suppressed and you will maintain altitude, heading and speed for a few moments by the sole use of the instruments.    

 

Next you will be requested to carry out minor altitude changes of maximum 50 ft upwards and downwards, maintaining the new altitude for a few moments after each change. This must be done while maintaining the heading unchanged, which requires to keep the wings level. Trimming is not required for such transient manoeuvres.           

 

Basic l.F training also includes partial panel operations whereby the attitude indicator and the directional gyro are covered to simulate a pneumatic system failure, the turn indicator being electrically driven. Note that a gyroscopic instrument rarely fails abruptly: the process is very gradual because the gyroscope needs time to stop rotating. During this rundown the indications of the involved instrument become increasingly erratic, but it can take a while before the pilot realizes the problem: this is one more reason to constantly crosscheck all instruments with each other.      

 

Such failures can be programmed in the simulator. However, at this stage, the instructor might simply cover the attitude indicator and the D.G., as will be done in the aircraft. Incidentally, assuming such a failure in real flight it is recommended, to avoid confusion, to cover the affected instruments anyway as soon as the problem is detected. Moreover, if it happens in IMC, the ATC must be notified at once of the problem: "O-XX, gyro failure" , and if in radar covered area add: "request radar assistance"

 

You will now maintain straight and level cruise flight in partial panel, then perform small altitude changes as previously. Whereas with a full panel the attitude indicator is the main reference, because it provides both bank and pitch information, in partial panel the turn indicator should be used to maintain a constant heading (which is now solely indicated by the magnetic compass), while the VSI should be used to maintain a constant altitude. If a turn coordinator is available instead of a turn-and-bank, remember that it provides an indication of bank as well as of yaw. Therefore the turn indicator is more practical in partial panel operations than its turn-and-bank counterpart. When it comes to perform minor altitude changes, simply act very lightly on the control wheel to obtain an up or down trend on the VSI (not more than 200 ft/min), and bring its reading back to zero in the same fashion as soon as the required altitude change is completed.

 

Having reverted to full panel, significantly de-trim one way or another and try to maintain normal cruise flight: you will notice that it becomes extremely arduous to maintain your altitude under this condition. This experiment emphasizes the need to be properly trimmed at all times. 

 

C) FLIGHT TRAINING        

 

Nil       

 

 

 

A) BRIEFING

 

Review the basic I.F. principles described before.       

 

Also review the magnetic compass errors due to turning, accelerations and decelerations¡ use of VRF/DF, short field operations, spot and forced landings as well as precautionary landing. All these subjects are discussed in the ELEMENTARY FLIGHT TRAINING MANUAL and are to be reviewed once in a while¡ particularly if the basic IF training is combined with the transition to another aircraft type.  

 

B) SIMULATOR TRAINING

 

You recall that a rate 1 turn implies a direction change of 3° per second which amounts to a full 360° turn in 2 minutes or 180° in 1 minute, 90° in 30 seconds, 45° in 15 seconds, or 30° in 10 seconds. Let us decompose the rate 1 turn as follows:    

 

1°) Using solely the control wheel, smoothly apply ailerons to one side, taking care to maintain the model aircraft's nose on the horizon bar, until the turn indicator shows rate 1. Once rate 1 is obtained, maintain the associated bank angle and verify its value in degrees on the attitude indicator;

 

2°) Observe the ball: if it is out of centre, it must be re-centred by depressing the rudder pedals as necessary. Take care however that the bank angle does not change due to the secondary effect of the rudder and that the model aircraft's nose remains on the horizon bar;          

 

3°) Draw now your attention to the VSI: if it shows a DOWN trend it must be brought back to zero by elevator input, thus putting the model aircraft's nose very slightly above the horizon bar. No trimming is required here, as the turn is basically a transient manoeuvre;  

 

4°) Check the ASI: if elevator is required it will perhaps read a slightly lower than normal speed which should be corrected by increasing power as required;

 

5°) Check the altimeter: assuming a slight altitude discrepancy due to the previous DOWN trend on the VSI, correct it just as you did in level flight, by a small pitch up until again at the initial altitude. The resulting slight speed decrease due to this corrective action being temporary¡ it may be disregarded: the ASI will come back to the normal value as soon as this additional pitch up is removed.           

 

When correctly established in the turn, maintain it for a few moments until the instructor calls for roll out. Proceed as follows:

 

1°) Using solely the control wheel, bring the wings back to level attitude while maintaining the model aircraft's nose position unchanged; 

 

2°) As soon as the wings are level, draw your attention to the ball: here again, if it is not centred its position must be corrected by rudder input, taking care to maintain the bank angle to zero;

 

3°) Check the VSI: now it might read an UP trend due to the elevator input required during the turn; correct this UP trend by lowering the model aircraft's nose back on the horizon bar, possibly slightly lower to recover the required altitude;   

 

4°) Check the ASI: if the power setting had to be increased during the turn, the speed will now show a tendency to exceed the required value (thus creating additional lift and a renewed tendency of the VSI to show an UP trend). This must be avoided by reducing the power setting back to normal cruise.           

 

A similar turn analysis in the opposite direction might reveal slightly different flight control inputs (rudder inputs in particular, due to the propeller effects). At any rate, all these inputs and associated corrections are so very small that an outsider next to you could hardly perceive them. 

 

You will now perform a few rate 1 turns to the left and to the right, but this time with emphasis on the proper coordination of the various required control and power inputs. This requires a quick scanning of the instruments mentioned above. You will soon acquire the ability to anticipate on the aircraft's reactions. In other words, you will apply the required corrections even before their need clearly shows on the instruments. Initially you will be instructed as follows: "RATE 1 TURN LEFT ROLL OUT", "RATE 1 TURN RIGHT ROLL OUT", etc. At this stage no specific heading will be given: it is simply a matter of correctly entering, maintaining and rolling out of the turn.

 

The next exercise is similar to the previous one except that this time you will be requested to roll out on specified headings and that, besides the other instruments, the D.G. comes into the picture. In order to avoid overshooting the required heading it is necessary to start the rollout 5° to 10° before it is reached. Some instructors recommend a lead of la for every 2° of bank angle (the bank angle being a function of speed, as will be discussed in lesson 03). Three remarks about these exercises: 

 

1°) Do not keep staring at the D.G. during the turn: unless the heading change is small and requires less than rate 1 (see below), it takes quite some time to come in the vicinity of the required heading: during this time, concentrate essentially on the previously mentioned instruments, allowing only occasional glances at the D.G. so as to start the rollout in due time. Even then, keep concentrating mainly on the other instruments to perform a gradual and satisfactory rollout.       

 

2°) Do not forget to crosscheck the D.G. with the magnetic compass after each turn (although this requirement is mainly of importance in the actual aircraft rather than in the simulator). 

 

3°) Always remember that when flying IFR in VMC, even when under positive radar control, you remain responsible for the look-out: even in the simulator take the habit of calling "CLEAR LEFT" or "CLEAR RIGHT" before engaging in a rate l turn.   

 

Besides rate 1 turns, you will also be instructed to perform small heading changes. The following basic rule prevails:

 

- for 1° heading change, l° of bank angle          

- for 2° heading change, 2° of bank angle         

- ...

- for 5° heading change, 5° of bank angle         

- ...

- for 10° heading change, 10° of bank angle, etc. until either rate 1 or 30° of bank angle, whichever comes first, is attained and should not be exceeded.      

 

Finally you will perform a few rate 1 turns either side in partial panel, initially without heading requirements, then towards assigned compass headings:     

 

1°) Work with very gentle control inputs,

 

2°) Watch the VSI to stay at zero, and the turn indicator so as not to exceed rate 1. Turning at 1/2 rate helps to reduce the turning errors,    

 

3°) Maintain the airspeed unchanged by re-adjusting slightly the power setting if necessary, and keep the ball centred;    

 

4°) If you must pick up a specified heading, observe the magnetic compass only occasionally in order to start the rollout in due time and in this concern, be sure that you remember the theory on the compass' turning errors.   

 

5°) Roll out very gently, then maintain the turn indicator at zero deflection while the magnetic compass steadies. Don't forget to reduce the power setting to normal cruise value if it had to be increased during the turn, and maintain the VSI at zero;        

 

6°) Don't worry if, after rollout, you are not exactly on the required heading: notice the actual one, then correct gradually with small inputs towards the required value.  

 

 

In order to maintain the compass heading and the altitude, watch mainly the turn coordinator showing no deflection, and the VSI showing zero.          

 

Note that some turn indicators show a tendency to oscillate each side of zero, especially under choppy conditions. As long as the amplitude of these oscillations is the same to the left as to the right, they may be disregarded. However, if you notice that the oscillation is more marked to one side, or that the needle tends to stick to one side, you are probably turning: check the compass and correct as required.         

 

C) FLIGHT TRAINING         

 

Normal cruise and rate 1 turns in full and partial panel as per simulator lessons 01 and 02.      

 

When in actual flight with no external references, you might occasionally be faced with the phenomenon known as vertigo whereby physical impressions which are in contradiction with the instrument readings are experienced. For instance: although the instruments show a bank to one side, the pilot may feel as if the aircraft is banked to the other side. Such impressions may become so strong that one may be induced to react according to these rather than to the instrument readings which, needless to say, can give way to extremely dangerous situations. Remember that BELIEVING THE INDICATIONS OF THE INSTRUMENTS IS A VITAL ASPECT OF I.F.!! However, be also aware that ANY INSTRUMENT MIGHT FAIL, which is why a constant crosscheck is so utterly important.           

 

The causes for vertigo are the same as for the common airsickness (see "Basic Aerobatics"), and can be triggered by factors such as fatigue, stress or fear. Acute vertigo is likely to occur to pilots venturing in solid IMC with little or no training in instrument flying, particularly in turbulent conditions, and can easily lead to disaster.        

 

Weather conditions are often a little bumpy. Remember that aircraft are inherently stable and, as such, they tend to return by themselves to their initial attitude when disturbed from trimmed flight. Avoid reacting too quickly, particularly on the ailerons: keep the flight controls as steady as possible, and as lightly as possible, and apply correction only if the deviations become too marked.         

 

Remember that, unless it is of the slaved type, you must verify the D.G. against the magnetic compass at regular intervals during straight flight to take care of possible apparent drift errors as well as after each turn. This verification is to be carried out under following conditions: wings level, steady speed and little or no turbulence.    

 

The return to base will be carried out in full panel, using the R/T either to obtain VHF/DF bearings or radar vectorings. If none of these facilities is available, the instructor shall fill the role of the ground station to bring you back to the airport.

 

 

Although VHF/DF has already been discussed in the ELEMENTARY FLIGHT TRAINING MANUAL, remember that upon first call, as well as each time that you are requested to transmit for DF, you should specify your heading and altitude: these information are much more useful to the ATC controller than the usual 12345 count. The EVRD (External Vision Restricting Device) which was initially put in place in cruise flight, shall be removed once the aircraft is in close vicinity of the base.

 

As said before, it is not because this training phase relates to basic I. F. (or later to basic radionavigation) that other aspects of flying are to be disregarded. Each minute must be used either to acquire new abilities or to review previously learned material. No "idle" flying should be tolerated. Always keep the following in mind:   

 

1°) During all phases of flight requiring constant altitude, heading and speed, these parameters are to be maintained respectively within ± 100 feet, ± 10° and ± 10 kts, with the understanding that these are maximum allowable deviations: the "target" values must always be recovered as soon as any deviation is noticed. THIS IS APPLICABLE TO BOTH VISUAL AND INSTRUMENT FLYING!!!  

 

2°) During all phases of flight, correct trimming is essential: flight controls should be held lightly, and even totally released at regular intervals to verify proper trim    

Setting;         

 

3°) Look-out remains essential at all times, particularly before and during turns. As long as no EVRD is installed, look-out is your own responsibility; with the EVRD installed, do not forget the calls "CLEAR LEFT" or "CLEAR RIGHT", were it only to remind your instructor (or safety pilot) to watch for other traffic.  

 

It is assumed that you know the aircraft and that you are fully cognizant with its systems and handling characteristics or, assuming that you are using a new type, that you have been sufficiently introduced to it (see "Transition to another aircraft", lessons 01 and 02). During the first basic I.F. flight sessions, the EVRD will only be used in level fligh conditions. During all other parts your proficiency in the following fields shall be tested:         

 

1°) Short field takeoff using the technique as published in the POH, maintain Vx after liftoff until ± 500 ft AGL, then continue climb at Vy until requested to proceed at cruise climb until cruising altitude. Do not forget the after takeoff checklist!          

 

2°) During climb, the instructor will cover the D.G. and request you to pick up one or more compass headings.

 

3°) Levelling off at the assigned altitude and establishing the aircraft in normal cruise (normally at 65% power) on the last assigned compass heading, aircraft properly trimmed and mixture adjusted as required (do not forget the cruise checklist) . The instructor will then uncover the D. G. and proceed with the I.F. training.       

 

 

4°) This first flight will end with either a forced or spot landing, a short field landing, or a precautionary landing.       

 

 

 

A) BRIEFING

 

Review the basic I.F. principles described before.       

 

Review propeller effects (see associated PILOT NOTE), spot landings, practice forced landings, etc., and general abnormal situations in the ELEMENTARY FLIGHT TRAINING MANUAL.           

 

As flight at various speeds will be studied during this lesson, remember the following:   

 

1°) The airspeed is directly controlled by the power setting, thus by the throttle lever. The VSI, thus climb and descent, is directly controlled by action on the elevator.         

 

2°) Whenever power is reduced, the aircraft's nose shows a tendency to pitch down which must be counteracted by backward elevator input; conversely, when power is increased, it will cause a pitch up which must be counteracted by forward elevator input.       

 

3°) Also landing gear and flaps operation are likely to influence the pitch attitude (in this concern, maybe the simulator does not react in the same way as your training aircraft). 

 

4°) As flying at low speed requires a high angle of attack and a significant amount of power, the slower the speed the more the propeller effects will become noticeable, and the more rudder input will be needed to counteract them.           

 

5°) As far as reduced speeds are concerned, remember that the manoeuvring speed, or VA, is to be used if you are caught in severe turbulence. Ensure that you are cognizant with its value for your aircraft type (see also "Basic Aerobatics") .           

 

6°) As far as rate l turns are concerned, keep in mind that the required bank angle decreases as the speed decreases. A rule of the thumb to find the approximate required bank angle is as follows:         

 

ASI/10 + half the result

 

Thus, for an lAS of 100 kts:

 

100/10 = 10 + 5 = ±15° bank angle          

 

With increasing speeds, the required bank angle will increase but should not exceed 30° during normal I.F. operations.         

 

B) SIMULATOR TRAINING

 

The instructor shall initially let you perform some straight and level flight at normal cruise as well as a few rate 1 turns with rollout on a specified heading. These exercises shall be carried out in full panel. Then:

 

1°) With the aircraft properly established in normal cruise at a specified altitude, you will now increase power to maximum while leaving the control wheel free: observe the model aircraft rising above the horizon bar and the resulting increasing vertical speed and altitude, as well as the decreasing airspeed. Still leaving the control wheel free, reduce now the power to near idle: observe the model aircraft dipping below the horizon bar, the resulting decreasing vertical speed and altitude, as well as the increasing airspeed.           

 

2°) Repeat the same exercise, but this time maintaining the model aircraft on the horizon bar by use of the elevator (no trimming is required at this stage) and notice the following:         

 

- When power is increased, and that the pitch attitude remains unchanged, the speed increases. However, due to the resulting lift increase, the VSI still shows an UP trend and a gradual increase of altitude occurs,           

 

- When power is decreased, and that the pitch attitude remains unchanged, the speed decreases. However, due to the resulting lift decrease, the VSI still shows a DOWN trend and a gradual decrease of altitude occurs.          

 

3°) Repeat again the exercise, but keep now the altitude unchanged by eliminating the effects of lift change, i.e. by modifying the angle of attack. This requires very gentle elevator inputs so as to position the model aircraft slightly above or below the horizon bar, thus maintaining the VSI at zero. Be aware that the movements of the model aircraft in relation to the horizon bar are mostly very small, say between a half and a full width of the horizon bar, except at very low speeds where the model aircraft will be more noticeably above the horizon bar. Note also the pitch indications in degrees on the attitude indicator.    

 

4°) Following these introductory exercises you will now be requested to reduce the speed to a specified value, for instance to VA (manoeuvring speed), departing from normal cruise, while maintaining heading and altitude. To this purpose, reduce power sufficiently to obtain a gradual speed decrease and maintain the VSI at zero: as speed decreases apply short trim increments to eliminate the required pull force on the control wheel. Remember that, as the heading must be maintained, it is important to keep the wings level in the process. Remember also that, once the required speed is reached, some power increase might be necessary to maintain it. When the required speed is obtained, check proper trimming once more and verify that the wings remain level, heading and altitude unchanged, and ball centred (think about possible propeller effects). Apply possible required corrections smoothly but without delay. Assuming that VA is the target speed, once properly established, take note of the required power setting and the degrees of pitch up on the attitude indicator, and memorize these parameters: if ever you must reduce to VA because of sudden heavy turbulence, all you have to do is to select the associated known power setting and pitch attitude: the speed will settle automatically at VA (note that, under heavy turbulence conditions, VSI and altitude variations are to be disregarded: simply maintain wings level).        

 

5°) Reduce further to circuit speed, i.e. initial approach speed (usually within the white arc on the ASI), following the same procedure as here above. Here again, memorize the required power setting and pitch attitude when properly established and trimmed.  

 

6°) Perform now the approach checklist (SBLUMFFSCIN - see ELEMENTARY FLIGHT TRAINING MANUAL) but leave the flaps (and the landing gear) up for the time being. Ensure that you are sufficiently cognizant with this checklist so as to perform it completely, quickly and efficiently. Keep in mind that flying the aircraft accurately. thus watching your flight instruments is of primary importance. NEVER DIVERT YOUR ATTENTION FROM THE FLIGHT INSTRUMENTS FOR MORE THAN THREE OR FOUR SECONDS!!! Here again, do not delay possible required corrections and, if necessary, interrupt the checklist a few moments to apply these corrections (but do not forget to complete it afterwards).  

 

7°) As the landing gear and flaps were left up, investigate now the reactions of the simulator to their operation (again, these reactions might be reversed in the actual aircraft) and verify if these reactions are similar to those of your training aircraft. To this purpose, release the control wheel completely and select the flaps to their initial position. You approach will immediately notice a tendency either to pitch up or to pitch down: you must be prepared to counter this tendency at once by use of the elevator. Furthermore, remember that selecting the flaps downwards increases both lift and drag: see to it that the VSI remains at zero, again by use of the elevator and, if you wish to maintain the speed unchanged, it will be necessary to increase power slightly (an alternative way is to let the speed drop and to maintain a predetermined lower value). Adjust the trim for this new configuration. If the aircraft is fitted with a retractable landing gear, release again the control wheel and lower the landing gear to verify if its operation causes any pitch and/or speed variations. If necessary, correct as you did for the flaps.           

 

8°) Reduce speed further to maintain Vs + 10 kts and re-trim. At such low speeds it will be necessary to position the model aircraft significantly above the horizon bar and, as you are now flying at a high angle of attack, the drag is considerable and quite some power is required to maintain the speed. Check also the ball and keep it centred: the propeller effects are much stronger under these flight conditions.   

 

9°) At Vs + 10 kts, you will perform a few rate 1 turns in either direction. Notice the reduced bank angle to obtain rate 1 and compare this bank angle with the rule explained earlier in this lesson. Be careful: flying at low speed and high angle of attack may give way to engine overheat: watch the CRT and the oil temperature. If cowl-flaps are available, it may be necessary to open them (but don't forget that this also causes additional drag). Remember the need to include the secondary instruments at regular intervals within the scanning.

 

10°) At Vs + 10 kts, and on a specified heading, apply cruise power and retract the landing gear. As speed increases, maintain the VSI at zero by gradually bringing the model aircraft back on the horizon bar with the elevator. Maintain the wings level and check that the ball remains centred (do not forget to release the rudder input which was probably needed at low speed). As the speed approaches the upper limit of the white arc, retract the flaps: if you keep the VSI at zero, the speed will settle automatically at normal cruise value (unless you forget to close the cowl-flaps if these were opened). During the whole of this process it will be necessary to trim "nose down", preferably using small increments as the speed builds up, to eliminate the required force on the control wheel.           

 

When back in normal cruise, you will now again reduce speed to various specified values, still maintaining heading and altitude, but this time in partial panel. Proceed as follows:       

 

1°) verify the compass heading before starting the exercise. Remember that the magnetic compass, besides being subject to errors during turns, also shows errors during accelerations and decelerations. This means that (except on the North-South axis) its readings are unreliable whenever the speed varies and that, in order to maintain the heading, you must rely on the turn indicator and keep it as steady as possible.     

 

2°) Remember also that small oscillations of the turn indicator's needle may be disregarded provided that their amplitude is equal to both sides. If you notice that the needle deflection is more marked or that in tends to stick to one side, even for a second or two, this indicates a turn to that side: if this happens, turn slightly to cause the needle to deviate to the opposite side for approximately the same amount and the same duration, then revert to straight flight: needless to say that such corrections require extremely small control inputs.   

 

3°) Don't rush things and reduce or increase speed more gradually than in full panel. Maintain the VSI at zero and keep the ball centred.     

 

4°) When reaching each specified speed, don't forget to adjust the power setting as required to maintain this speed.   

 

5°) Each time that the speed is stabilized at a new value, or following a configuration change regarding flaps or landing gear, verify the reading of the magnetic compass which should be practically unchanged.      

 

Note: These exercises require a fair amount of anticipation. This will come with practice. Don't get discouraged because the required flight parameters (altitude, heading, speed) are varying rather significantly in the beginning: it will improve as training progresses. Don't be concerned too much with terms such as altitude "unchanged", heading "unchanged" or speed "unchanged": the pilot who is able to fly with ever "unchanging" parameters is still to be born. Some variations will always occur. You simply must try to keep them as small as possible and, when you notice them, apply the required corrections as soon as possible and as smoothly as possible. But YOU MUST REMAIN CONCENTRATED. And, as long as the attitude indicator is available, this is the instrument to which you must revert to apply the required corrections. BEWARE OF ABNORMAL PITCH AND/OR BANK ANGLE INDICATIONS!        

 

C) FLIGHT TRAINING

 

Repetition of the exercises carried out in the simulator. Assuming that the aircraft is fitted with a turn-and-bank instead of a turn coordinator, your instructor will momentarily take aver the controls and show you that its needle is not influenced by the bank angle. He will bank the aircraft to one side and maintain this bank angle while applying opposite rudder to avoid the aircraft's nose to yaw towards the low wing: notice then the needle still centred and the ball showing a considerable slip (the term "turn-and-bank", which is often used, is in fact inadequate and should be replaced by the term "turn-and-slip", or "needle-and-ball").         

 

The return to base will be carried out in partial panel by means of actual or simulated VHF/DF or radar vectoring.    

 

Besides the I.F. training, the general flight shall be carried out in the same way as the previous lesson.

 

 

A) BRIEFING

 

Review the basic I.F. principles described before.       

 

Review the climb and descent theory in the ELEMENTARY FLIGHT TRAINING MANUAL.       

 

As was stated in the previous lesson, airspeed is directly controlled by the throttle lever while climb or descent is directly controlled by elevator input. 

 

With the comfort of the passengers in mind, descent rates of more than 500 ft/min should be avoided on non-pressurized aircraft. There is no such limitation in climb.           

 

Remember that climbing can be carried out in three ways: at Vx, at Vy or in cruise (or normal) climb. In the simulator, the corresponding speed and power values will be specified by your instructor (they are published in the POH of your training aircraft) . Remember also that the propeller effects become particularly apparent at low speed and high power. Thus, during climb, and especially at Vx, it will be necessary to closely watch the ball and apply the required rudder corrections to keep it centred.         

 

B) SIMULATOR TRAINING           

 

1°) Departing normal cruise, apply maximum allowable power (this is usually full power on light general aviation aircraft, but could also be METO power - see ELEMENTARY FLIGHT TRAINING MANUAL) and simultaneously apply back pressure on the control column to put the model aircraft about two to two and a half widths above the horizon bar;    

 

2°) Maintain the model aircraft in its new position, adjust the trim and let the speed settle at a steady value. In the meantime, maintain the wings level and check that the ball remains centred;    

 

3°) Check the ASI and, if necessary adjust the model aircraft to obtain exactly Vx and re-adjust the trim. Note the rate of climb and, in view of subsequent Vx requirements (for instance for instrument takeoffs - see next lesson), memorize the required pitch attitude;         

 

4°) Re-adjust the model aircraft to a somewhat lower position to obtain exactly Vy. Adjust the trim once more and note again the rate of climb: it will initially decrease due to the lowering of the nose but, after a few moments, it will increase again and settle at a higher value than at Vx. Also memorize the required pitch attitude for Vy;      

 

5°) Adjust once more the model aircraft in order to obtain cruise (or normal) climb speed, reduce power to the specified setting, trim, and memorize the required pitch attitude.      

 

To level off at a predetermined altitude and resume normal cruise, proceed as follows:  

 

1°) A certain amount of lead must be taken to avoid overshooting the assigned altitude. This lead should be about 10% of the vertical rate. For instance, if the rate of climb is 500 ft/min, the level off should be initiated 50 feet before the assigned altitude;

 

2°) Lower the model aircraft gradually so as to reach alignment with the horizon bar at the same moment that the assigned altitude is attained, and re-adjust the trim in small increments during this process. Do not reduce power before the airspeed approaches the cruise value; 

 

3°) Keep in mind that, once the model aircraft is back on the horizon bar, as long as the speed is building up it will be necessary to apply forward pressure on the control wheel to maintain the VSI at zero: it will thus be necessary to keep trimming, still using small increments, until the required speed is reached and that the power is reduced to normal cruise;

 

4°) Maintain the wings level and the ball centred during the whole level off process.      

 

Descents can be carried out at any speed up to Vne. Adjust the required vertical speed (500 ft/min on non-pressurized aircraft) with the elevator and obtain the required airspeed with the power setting. Obviously, if the engine is in idle (which is not recommended in normal operations on piston engined aircraft because of cooling considerations, but which can be done to simulate an engine failure), the only way is to adjust the required speed for best gliding with the elevator and to accept the ensuing rate of descent.

 

For the purpose of the exercise, you will now initially reduce to circuit speed while maintaining altitude and heading. Once established and properly trimmed:           

 

1°) Apply forward pressure on the control wheel to position the model aircraft about one width below the horizon bar and reduce power to avoid an excessive speed build up;    

 

2°) Maintain the model aircraft in its new position, adjust the trim and wait until the VSI and ASI settle. In the meantime, keep the wings level and the ball centred;

 

3°) Adjust now the VSI at exactly 500 ft/min by appropriate elevator input, adjust the throttle lever to maintain the assigned airspeed, and finalize the trim setting;         

 

4°) To level off at a specified altitude, use again the lead rule of 10% of the vertical rate, gradually bring the model aircraft back in its previous position, increase power to maintain the speed unchanged, and re-adjust the trim.         

 

Remember that the descent can be carried out in a number of variants: instead of descending at circuit speed you might use normal cruise speed or even let the speed build up to any higher value up to Vne. Assuming that you wish to use a higher speed (which is an interesting proposal in order to gain time when descending from higher altitudes towards a destination airport, as will be seen in operational IFR), all you have to do is to depress the model aircraft below the horizon bar in order to obtain 500 ft/min on the VSI, use small trim increments to keep the nose down while the speed builds up to the required value and, when this value is reached, reduce power to maintain it. Also remember that, in turbulent conditions, the speed should be reduced within the green arc or, in heavy turbulence, to VA: this requires an appropriate power reduction, a re-adjustment in pitch to maintain the rate of descent unchanged, and a re-adjustment of the trim setting.    

 

The next exercise, known as a vertical S, aims at developing your instrument scanning as well as your coordination of· flight controls, throttle lever and trim: 

 

1°) Reduce to Vy while maintaining heading and altitude. Assuming a constant speed propeller, select high rpm; 

 

2°) On heading, start climbing at Vy, but this time maintaining a specified rate of climb, for instance 500 ft/min (note that on most low powered aircraft this will probably require practically full power);          

 

3°) When passing the 500 or 1000 ft mark above the departing altitude, gently initiate a descent, still at Vy, heading unchanged, at 500 ft/min rate of descent;       

 

4°) When reaching the departing altitude, initiate again a climb at 500 ft/min, at Vy, same heading, etc.

 

This exercise shall be continued on a constant heading for two or three more "ups" and "downs". The instructor will then request you to combine each altitude change with the execution of a 180° rate 1 turn, alternatively to the left and to the right.   

 

The exercise will then be repeated, however maintaining heading only (no rate 1 turns at this stage) in partial panel.

 

Next exercise is a preparation to the future approach and missed approach procedure (assuming a final descent to the meteorological minima followed by a go-around):      

 

1°) Establish circuit speed and perform the approach checklist (SBLUMFFSCIN - see ELEMENTARY FLIGHT TRAINING MANUAL) and select now the flaps to initial approach configuration. Remember to be careful when you do so: the flaps produce lift which causes the aircraft to gain altitude, they cause an up or down pitch, and they produce drag. Do not fail to maintain the VSI at zero, to adjust the power to maintain the required speed, and to adjust the trim. Assuming a retractable landing gear, keep it up for the time being (unless the landing gear warning horn causes too much annoyance);    

 

2°) When ready, start descent at 500 ft/min towards an altitude specified by the instructor and which will be the theoretical minimum at which a go-around must be initiated. Assuming a retractable landing gear and/or a constant speed propeller, extend the landing gear and select high rpm just before you start the descent. When properly established at 500 ft/min, at the required speed and properly trimmed, check and memorize the pitch attitude and the power setting for later use in IFR operations. Perform the landing checklist (FUCP);

 

3°) During this descent, the instructor will ask you to vary slightly the rate of descent, for instance to 300 ft/min or to 600 or 700 ft/min, simulating small corrections to stay on a theoretical glide path: this must be done using extremely gentle pressures on the control wheel and without changing power (as long as these corrections are of transient nature, the airspeed will hardly deviate from target value). At 100 feet above the limiting altitude, call out "100 FEET" and maintain the rate of descent unchanged; 

 

4°) Upon reaching the limiting altitude, NOT BEFORE, apply full power and pull the control wheel to position the model aircraft in the correct attitude for Vy;      

 

5°) Verify that pitch attitude is correct, that wings are level and that airspeed is steady at or increasing to, Vy and retract the landing gear. In case of a real go-around you should notify the ATC by the words "MISSED APPROACH";         

 

6°) Upon reaching a safe altitude of at AT LEAST 300ft AGL, retract the flaps and perform the after takeoff checklist. The last exercise of this session will be a high speed descent close to Vne, 500 ft/min, possibly combined with rate 1 turns to the left and to the right to specified headings.          

 

C) FLIGHT TRAINING         

 

Repetition of the exercises carried out in the simulator.          

 

Keep in mind the ever present possibility of an engine failure during or shortly after takeoff. It is therefore essential to use the full runway length for every takeoff, even on the longest runways (unless special requirements are in force). In addition, using the short field takeoff technique adds an additional safety factor.

 

Al though these matters have been discussed previously (see ELEMENTARY FLIGHT TRAINING MANUAL), let us review once more the so-called crew briefing (self-briefing if you are the sole pilot): 

"Rotation speed . . . kts, Vx . . . kts, Vy . . . kts. If engine fails   before takeoff: "no/light/heavy braking required. Notify ATC. If engine fails after takeoff, nose down, "best gliding speed . . . kts landing straight ahead avoiding major obstacles. No turn "before nose is down. Mixture ICO, fuel OFF, ignition and master switches OFF, cabin "door(s) unlocked".          

 

This briefing should be carefully recited, or read (loud and clear if there is another pilot in the right seat) before every future takeoff.

 

Conditions permitting, the instructor will momentarily reduce power to near idle shortly after takeoff to verify your initial reaction to establish a proper gliding attitude as well as your ability to choose a suitable landing spot, and to carry out (obviously simulating) the required checks, before applying full power again and resume climb. Level off will be performed at a specified altitude (1000 to 1500 ft AGL) at which moment the EVRD will be installed for further I.F. training.    

 

The return to base will be carried out in full panel using either VHF/DF or radar vectoring as previously.           

 

Assuming that weather conditions are suitable, and particularly if the basic I.F. training is combined with the transition to another aircraft, a practice forced landing shall be executed, departing from 2000-3000 ft AGL in the immediate vicinity of the airport. If weather is not suitable for this exercise, the instructor will "radar vector" you to the final approach.

 

 

 

 

A) BRIEFING

 

Review the basic I.F. principles described before. Taking off with no sight at all of the runway is a purely academic exercise as, in the real world of IFR operations, any takeoff requires a minimum of forward visibility. Although after completion of this basic I.F. course you may, and you should, continue practicing with a safety pilot on board, the takeoff on instruments is not to be attempted without the presence of a duly qualified instructor or examiner in the right seat. Neither should it be attempted under excessive crosswind conditions. 

 

Although turns are normally restricted to a maximum bank angle of 30° during instrument flying, in order to improve your coordination and self-confidence, they will now be carried out with 45° bank angle which, in fact, is still far away from the so­called maximum performance turn (i. e. a turn at maximum bank angle, at a speed close to stall).

 

Review the forces acting in a turn, as well as the theory about steep turns, in the ELEMENTARY FLIGHT TRAINING MANUAL. There is no essential difference between a normal turn and a 45° banked turn. In fact, most students experience no major difficulty to perform this manoeuvre at least not under full panel conditions.   

 

At 45° of bank, some D.G's have already a tendency to become erratic. Despite the fact that they usually have. a freedom of 55 ° around both pitch and roll axes, gimbal error becomes more marked as bank increases and can produce a rather significant precession and consequent drift. Because of this, it is essential that after each turn or serie of turns, and certainly in case of 45 ° banked turns, the D.G is verified against the magnetic compass. Remember the conditions required to this purpose, wings level, steady speed, little or no turbulence.      

 

Finally, remember the need for look-out and don't forget to call out "CLEAR LEFT" or "CLEAR RIGHT" before initiating the turns. 

 

B) SIMULATOR TRAINING

 

In the simulator you will be aligned exactly in the runway axis. Proceed as follows for the instrument takeoff:          

 

1°) The D.G. may be aligned on the nearest 5 or 10° mark (or align the bug): this will contribute to maintain the direction or the runway more precisely during the takeoff roll;

 

2°) Release the brakes and gently apply full power while maintaining the D.G. (or bug) properly aligned with the rudder. When full power is set, quickly check the engine instruments, the rpm and the ASI and call out "POWER SET, AIRSPEED INCREASING";          

 

3°) The D. G. is the primary instrument during the takeoff roll. Be prepared to correct for propeller effects. It is essential that you maintain the D.G. heading unchanged during this phase: tailing this might bring you dangerously close to the runway edge. Exert forward pressure on the control wheel to increase nose wheel friction and obtain better rudder control. Keep also an eye on the ASI in order to initiate the rotation at the correct speed; 

 

4°) Upon reaching rotation speed, divert your attention from the D.G. to the attitude indicator which now becomes the primary instrument: keep the wings level and apply back pressure on the control wheel so as to position the model aircraft in the known attitude to maintain Vx (or VY as required) and adjust the trim (at this stage, a gross trim adjustment is sufficient);  

 

5°) With the model aircraft in the correct attitude, quickly check that the VSI shows an acceptable rate of climb, that the altimeter shows a steady increase and that the ASI is steadily increasing to or stabilized at the required speed (or at least in its close vicinity): this state of things is referred to as a positive climb or, in other words, a safe climb (see below);

 

6°) As soon as you have, identified it as such, call out  "POSITIVE CLIMB" and, if the landing gear is retractable, apply brakes and select the gear UP. There is no hurry in retracting the landing gear: do it calmly and sedately, and make sure that you do not retract the flaps instead;          

 

7°) Keep your attention on the flight instruments and, when reaching safe altitude (at least 300 ft AGL) increase the speed from Vx or Vy to normal climb value, reduce power as required and perform the after takeoff checklist (mnemonic: ASBUF-FLP - see ELEMENTARY FLIGHT TRAINING MANUAL). Note that, with a retractable landing gear, the first part (ASBU) has already been carried out by identifying the positive climb and retracting the landing gear. In fact, all you have to think about is the last part: F-FLP standing for flaps UP, fuel booster pump QEE, landing lights as required and power set to climb power.        

 

The need for the after takeoff checklist is another occasion whereby one can easily divert his attention for too long a time from the essential flight instruments, looking for the various switches and levers which must be repositioned, and letting the aircraft wander into an unsafe situation close to the ground. Remember what has been said earlier for the approach checklist: never let your attention be diverted for more than three or four seconds from the flight instruments. As soon as a deviation is noticed, apply the required correction smoothly but without delay, possibly pausing a moment before completing the checklist.      

 

Coming back to the positive climb principle, remember that an attitude indicator may be erroneous or you might have positioned the model aircraft too high or too low. That is why it is imperative to crosscheck the other instruments. You might very well find yourself in a situation whereby you would have an excessive rate of climb and a decreasing airspeed, possibly resulting in a stall, or the other way around: a too low rate of climb and the airspeed rapidly increasing above the require value: the aircraft is then flying too fast with too little rate of climb . . . . . with possible obstacles in front. Remember also that the attitude indicator can be affected by acceleration errors, which is another reason to crosscheck its indications with the other instruments.   

 

After completion of the takeoff procedure and the associated checklist, maintain normal climb. Your instructor will request rate 1 climbing turns to the left and to the right! rolling out on specified headings, then request you to level off at a specified altitude and heading! and settle at normal cruise.    

 

Next he will ask you to notice the 45° left and right bank locations on the attitude indicator and request you to make a few turns at this bank angle in both directions. These turns will initially be carried out without the need to rollout on a specified heading: simply roll in upon request and maintain 45° bank angle until ordered to roll out. Don't forget the "CLEAR LEFT" or "CLEAR RIGHT" calls.

 

- Roll in and roll out gently. A very common error is to exert back pressure, and to increase power, too much and too soon. Don't do either as long as the VSI does not show a down trend, and that the airspeed does not show a tendency to decrease;

 

- Keep the ball centred all the time by means of the rudder, and don't forget that any correction on the rudder is likely to affect the bank angle;      

 

- When rolling out, maintain the VSI at zero and the airspeed unchanged: remember that if some back pressure was required during the turn, forward pressure will be required in the rollout to avoid a nose high attitude; similarly, if some additional power was required during the turn, it must be brought back to normal value upon rollout.       

 

The exercise will be repeated, but this time rolling out on specified headings. Remember that you must start the rollout in due time to avoid overshooting the required heading (about 20° of lead is appropriate).

 

You will probably experience no major problem with 45° banked turns in full panel. Note the deflection of the turn indicator's needle in the process as you will now use this deflection to perform 45° banked turns in partial panel:         

 

1°) Enter the turn very smoothly, watching now the turn indicator to pick up and maintain the previously noted deflection;   

 

2°) Maintain the VSI at zero and the airspeed steady, applying back pressure and additional power only when necessary;

 

3°) Keep the ball centred and maintain the turn indicator at the required deflection until requested to rollout (no heading will be specified in partial panel) ; 

 

4°) Rollout very gently by bringing the turn indicator gradually back to zero deflection, still maintaining the VSI at zero and the airspeed unchanged.    

 

At the end of this simulator session, once back in full panel, the instructor will induce a technical problem which you will have to identify (always think about crosschecking the secondary instruments at regular intervals) and which will lead to a precautionary reduction to idle, or a sudden engine failure. You are expected to pick up best gliding speed (in the simulator, use Vy), trim the aircraft, and perform the necessary checklists (see ELEMENTARY FLIGHT TRAINING MANUAL).       

 

C) FLIGHT TRAINING         

 

You will perform the takeoff on instruments unless excessive crosswind conditions prevail. If this is the case, don't worry, you will have enough opportunities to practice this procedure during subsequent training flights, including the radionavigation sessions.         

 

Normally the EVRD will be installed before initiating the takeoff roll. Some installations require the EVRD to be put in place prior to line up, in which case the instructor will steer the aircraft on the runway axis, bring it to a full stop, and notify you by calling "YOUR BRAKES, YOUR CONTROLS". Proceed then as follows:    

 

1°) Maintain the aircraft stationary with the toe brakes and, if so desired, adjust the D.G. on the nearest 5 or 10° mark; 

 

2°) Release the brakes by bringing the tiptoes on the lower part of the rudder pedals and apply full power, gradually but without hesitation: opening the throttle abruptly might cause the aircraft to yaw significantly due to the propeller effects and create directional problems at the onset of the roll. Carry on as you did in the simulator, but using the speeds published in the POH;           

 

3°) Assuming that a light crosswind prevails, keep the control wheel slightly deflected into the wind and keep it that way until liftoff: let the aircraft turn two at three degrees into the wind to maintain the runway axis as closely as possible, and resume wings level attitude.          

 

Note: When you execute a takeoff with an examiner or any other instructor in the RH seat and with the EVRD installed, besides the usual "crew briefing", do not fail to remind him that in case of engine failure before or shortly after takeoff. he is to take over the controls!!! 

 

Besides the takeoff on instruments, the 45° banked turns in full and partial panel, which are the repetition of the simulator session, will be executed. The remainder of this flight session is a review of matters which were previously covered: climbing at Vy, at normal climb, rate 1 turns, leveloffs, slow cruise, etc., as your instructor feels appropriate, all of these exercises being carried out in full panel (a similar review in partial panel is programmed on the next flight session).

 

In addition, you may expect a simulated sudden engine failure under I.F. conditions, following which you are expected to pick up the best gliding speed published in the POH and to maintain the heading. Don't forget to call out (to simulate) the various items of the checklist related to a forced landing (the 45° banked turns shall be carried out in the close vicinity of the airport and at an adequate altitude to allow the practice forced landing exercise). The EVRD will of course be removed at some stage to allow you to "find the landing spot" and to complete the landing.   

 

Assuming that the practice forced landing exercise cannot be carried out for whichever reason, the instructor will "radar vector" you back to the airport.     

 

Note: Talking about engine failures, remember that this might happen during the takeoff as well. This is why a takeoff with EVRD installed should never be carried out without an instructor or examiner in the right hand seat. Furthermore, never hesitate to add in your takeoff briefing: "IN CASE OF ENGINE FAILURE DURING TAKEOFF ROLL OR SHORTLY AFTER LIFTOFF YOUR CONTROLS!!!".

 

 

 

A) BRIEFING

 

Review the basic I.F. principles described before.

 

The flight training part of this lesson requires meteorological conditions allowing to climb at least to 2000 ft AGL in VMC. As weather conditions are often a problem, this lesson may be postponed to a later opportunity without upsetting the training progress. If such is the easel it will be replaced by lesson 07 which should be studied together with this one.          

 

Review the theory about steep turns, stall and spins in the ELEMENTARY FLIGHT TRAINING MANUAL.           

 

As far as instrument flying is concerned, any excessive bank and/or pitch is an unusual attitude. In fact, the 45° banked turns covered in the previous lesson are to be considered as such, the normal maximum bank angle being restricted at 30°. So is any pitch attitude which gives way to excessive vertical rates.           

 

An unusual attitude is not necessarily the result of some kind of loss of control, as many people seem to think. If a pilot looses the control of his aircraft because of inexperience or inadequate training (as has happened in the past, often with fatal result) the chances that he will be able to recover are close to nil anyway. Except in the rather unlikely case of a technical malfunction or conditions of extreme turbulence, both utterly remote occurrences, THERE IS STRICTLY NO REASON THAT A WELL TRAINED PILOT SHOULD LOOSE CONTROL OF HIS AIRCRAFT AND ALLOW IT TO TAKE EXTREME POSITIONS. The real purpose of practicing unusual attitudes during training is to further improve your self-confidence. Keep in mind the following basic principles:           

 

1°) When an excessive speed is noticed, first action is to reduce power, possibly to idle if required. Second action is to put the wings level, third action is to raise the aircraft's nose. Back pressure on the control wheel must be carried out carefully, particularly if the speed is increasing within the yellow range and approaching Vne: too strong an action on the elevator can give way to a high speed stall as well as to permanent structural deformations, or even failure (see "Basic Aerobatics"). It is imperative to verify that the wings are level before applying back pressure: pulling on the control wheel while the aircraft is banked almost inevitably gives way to a spiral dive whereby the bank angle increases further while the airspeed builds up rapidly to Vne . . . . . or beyond.     

 

2°) On the other hand, when an alarming low speed is noticed, power should be increased to maximum while lowering the aircraft's nose without delay, thence levelling the wings.          

 

 

3°) Levelling the wings, as well as raising or lowering the nose offers no problem at all as long as the attitude indicator remains in operation. However, if this instrument is out of service, because of toppling or any other cause, the only way to level the wings is by centring the turn indicator and (particularly with a turn-and-bank) the ball (remember that if you have a turn-and-bank, a centred needle does not necessarily mean that the aircraft is not banked). Regarding the pitch control, the elevator input must be checked by means of the VSI in combination with the ASI and the altimeter. Extreme care is required to avoid overcontrol and it must be remembered that, particularly in these circumstances, the VSI's indications lag considerably in comparison to the effect of the elevator's deflection. Because of this lag, the pressure on the control wheel, once applied must be momentarily relaxed (but not removed) as soon as the required trend shows on the VSI, then re-adjusted as necessary.      

 

4°) Remember the operating limitations of the attitude indicator (100° to 110° in bank, although some instruments allow 360° rolls, and 60° to 70° in pitch) and the D.G. (55° in both bank and pitch). In other words, unless you would come into a spin, the risk for being faced with toppling gyros is almost non-existent, even when flying in the worst turbulence conditions.

 

5°) Keep in mind that, in order to avoid unusual attitudes, it is imperative to constantly compare the various instruments with each other. Remember that a failing attitude indicator usually does not show an abrupt and obvious false reading: it will more likely display very gradual deteriorating pitch and/or bank information, so gradual in fact that they can easily go undetected to the pilot who should commit the basic and lethal error to stare at this sole instrument and follow its indications without reference to the others.      

 

B) SIMULATOR TRAINING           

 

Following exercises shall be carried out:           

 

1°) Reducing airspeed from normal cruise configuration to stall by throttling back to idle, maintaining wings level, ball centred and altitude unchanged until stall occurs. Let the aircraft break away, then recover.

 

2°) Repeating the previous exercise in partial panel. This might require two or more attempts.       

 

3°) Back in full panel, engaging in a 30° banked turn, reducing the power to near idle and maintaining altitude and bank unchanged until stall occurs. Let the aircraft break away, then recover.           

 

4°) Repeat the previous exercise to the other side.      

 

5°) Departing normal cruise, engage in a 60° banked turn to one side and keep turning until requested to roll out. In view of the subsequent 60° banked turn in partial panel, do not forget to note the turn indicator's deflection in the process.       

 

6°) Repeat the previous exercise to the other side.      

 

7°) Repeat the two previous exercises, but this time in partial panel. Chances are that trying a 60° turn in partial panel results in control problems of some kind, particularly during the first attempts. Don't let go things out of hand: recover if needed and try again (this is in fact the purpose of the exercise: to loose control, but to recover correctly . . . . . . . . " and if you can do these exercises without having to revert to any recovery action your coordination is perfect) .          

 

C) FLIGHT TRAINING         

 

Following the instrument takeoff, general review as in lesson 05, but this time in partial panel.

 

Unusual attitudes will include at least full stalls from straight and level flight with subsequent recovery, first in full panel then in partial panel, and 60° banked turns to the left an to the right in full and partial panel.

 

The instructor will take over the controls and put the aircraft in whatever position, combining excessive pitch and/or bank attitudes. Before doing so, in an attempt to induce vertigo, he will ask you to lean forward, to close your eyes and to turn your head sideways from left to right until the moment that he will release the controls and request you to take over and to recover. This exercise shall be performed in full panel and in partial panel.

 

The instructor will "radar vector" you back to the airport, providing you with the necessary instructions regarding heading, altitude and airspeed. He will tell you when to initiate the approach checklist: remember to select the flaps to the initial approach setting, but to keep the landing gear up (if retractable). He will vector you to a rather long final at about 1200-1500 ft AGL, then order the final descent at which moment (and if applicable) the landing gear should be extended and the propeller set to high rpm. Do not forget to go through the final checklist. The final descent is to be initiated at 500 ft/min and the instructor will constantly comment the approach, requesting minor heading and vertical speed correction to stay on the ideal approach path (much like a so-called GCA (Ground Controlled Approach), until ± 200 ft AGL at which moment the EVRD will be removed. Select then full flaps (having ensured that the airspeed has been reduced within the white arc) and complete the landing.  

 

Alternatively, and time permitting, the EVRD will be kept in place and the instructor will order a go-around, climbing straight ahead until 1000-1500 ft AGL. In this case, do not forget the after takeoff checklist. The flight will then be completed by either a spot landing or a precautionary landing. 

 

 

A) BRIEFING

 

Review the basic I.F. principles described before.       

 

Timed manoeuvres mainly allow to verify the accuracy of the VSI and of the turn indicator, and can be used for instance for aircraft IFR acceptance test flights.       

 

Timing may also be useful for direction changes with an unserviceable D.G. Indeed, assuming a rate 1 turn, and assuming that the turn indicator is correctly calibrated, the direction will change at a rate of 3° per second. This means amongst others:          

 

- 030° in 10 seconds          

- 045° in 15 seconds          

- 090° in 30 seconds          

- 180° in 60 seconds          

- 270° in 90 seconds          

- 360° in 120 seconds         

 

As far as the magnetic compass is concerned, correct timings combined with a correctly executed rate l turn may give way to discrepancies due to the compass deviation phenomenon. However, these discrepancies should be very small if the compass has been correctly compensated. Also keep in mind that when the D.G. is aligned with the magnetic compass, it is aligned with a so-called compass heading, not a magnetic heading. Therefore, if IFR operations are contemplated, and particularly NDB approaches under IMC conditions in mountainous terrain, it is of paramount importance that the compass deviations are reduced to at most one or two degrees by careful compensation.

 

B) SIMULATOR TRAINING    

 

Besides timed manoeuvres, this session will provide a general review with emphasis on matters which might have caused some difficulties during the previous training.   

 

During this session, the instructor may also face you with a number of additional problems such as carburettor icing, electrical or engine malfunctions, etc. Watch the secondary instruments and try to detect them in due time.    

 

The following exercises will be carried out:       

 

1°) In order to verify the accuracy of the VSI, maintain the heading and establish the aircraft in steady climb at 500 ft/min. When passing through a reference altitude, say for instance 2000 feet, start the stopwatch and check that you pass 2250 ft after 30" and/or 2500 ft after 60".                    

2°) Reset the stopwatch to zero, and initiate a descent at 500 ft/min. Start again the stopwatch when passing through a reference altitude, for instance 2500 feet, and check that you pass 2250 ft after 30" and/or 2000 after 60".   

 

3°) Reset the stopwatch to zero, level off at the specified altitude and resume normal cruise speed. When properly established, engage in a rate 1 turn to one side and maintain. When passing a cardinal point on the D.G. (N, S, E or W) start the stopwatch and verify that you pass the next cardinal point after 30", the following one after 60", the third one after 90" and the initial cardinal point after 120". Reset the stopwatch to zero, rollout on the following cardinal point, and repeat the experience to the other side.    

 

The readings of the VSI and the turn indicator, particularly those of the turn indicator, do not always match exactly the timing. This may be due to minor inaccuracies in piloting and timing, but can be as well the result of instrument errors. Instrument errors can be traced by repeating a number of times the same procedure and finding each time about the same discrepancy. As long as these instrument errors remain small they may be tolerated and you may either disregard them or apply the necessary correction, for instance keeping the VSI at 600 ft/min to obtain in reality 500 ft/min, or to position the turn indicator's needle at a slightly smaller or greater deflection than the rate 1 mark to actually obtain rate 1. Regarding the turn indicator, remember also the relationship between rate 1, bank angle and speed (see lesson 03). Errors in rate of turn may be caused by the calibration of the turn indicator, but also by D.G. gimbal error, or a combination of both.    

 

On the last heading, go to partial panel operation. Align the compass heading on the nearest cardinal point. You will be now requested to perform a 90° timed turn to the left (thus a 30" turn). Proceed as follows:         

1°) Engage in the turn and simultaneously start the stopwatch;       

2°) Maintain rate 1 as shown on the turn indicator (possibly applying a slight correction as might have appeared to be necessary during the previous experiments);

 

3°) Initiate the rollout after exactly 30", using exactly the same rollout rate;

 

4°) Let the magnetic compass stabilize: you should be very close to the heading at 90° from the initial one. 

 

Repeat the same experiment to the right: you should find yourself practically realigned with the initial heading. This experiment may be repeated with heading changes of 30° (10"), 45 ° (15" ), 180° (60"), etc. Note that if a calibration error is present in the turn indicator, discrepancies tend to increase with the amount of heading change. Furthermore significant discrepancies are likely if the magnetic compass is poorly compensated.   

 

C) FLIGHT TRAINING      

 

Repetition of the exercises on the simulator. Note that timed manoeuvres can only be accurate under smooth weather conditions. Therefore, this flight session might as well be postponed until a later opportunity.  

 

In addition, this flight session is a review of all other basic I.F. exercises, as was the previous one.

 

The basic I.F. course is now completed. Although you have gained a certain degree of proficiency in this field it is essential, particularly if you aim for the IR(A), to continue practicing in order to improve your newly acquired ability. Failing to do so rapidly leads to its deterioration. Anyway, the basic radionavigation course will provide you with further I.F. training.     

 

If you aim for the IR(A) or at the CPL(A) you must have a specified number of flying hours as PIC at your credit. Use some of these hours for practicing basic I.F. with a safety PILOT (we insist on the word "pilot", not a mere outsider) in the right seat. The sole purpose of the safety pilot will be to look out for other traffic while you are "on instruments". The safety pilot must know where and what to look for: that is why he MUST be a QUALIFIED pilot. Remember however that no instrument takeoff is to be carried out, unless an instructor or examiner is in the right hand seat.     

 

 

 

C) REVISION OUESTIONARY

 

ADI = Attitude Deviation Indicator i.e. artificial horizon.

 

01.- Which spot on the airport is the most suitable to check that the altimeter(s) reads correctly?          

 

02.- Aircraft at standstill. You notice that the VSI shows a slight UP or DOWN value. State two ways to correct it back to zero.

 

03.- During taxi, a left hand turn should cause the needle (or model aircraft) of the turn indicator to tilt to the _____, the ball to deflect to the _____, and vice-versa.       

 

04.- During taxi, turning to the left or to the right should not affect the indications of: a) the turn-and-bank, b) the turn coordinator, c) the directional gyro, d) the attitude indicator, e) the magnetic compass.           

 

05.- Aircraft at standstill. What do you check with regard to the magnetic compass?        

 

06.- A compass deviation card is required for: a) VFR flights, b) IFR flights, c) any flight.

 

07.- Explain the concept of "peripheral vision" during I.F.      

 

08. - What do you understand by "secondary instruments"?  

 

09.- Instrument scanning involves: a) the flight instruments b) the secondary instruments, c) both a and b         

 

10.- You lost both the attitude indicator and the D.G. in IMC. Which instrument do you use to ensure that the magnetic compass's heading remains unchanged? Which precaution is concerned as far as ATC is concerned?

 

11.- The suction gauge drops to zero during flight. This indicates a failure of the __________________. Which instruments are usually affected?

 

12.- You are flying with the EVRD installed (obviously with a safety pilot). Which precaution are you to take before initiating a turn?

 

13.- A rate 1 turn implies a direction change of _____° per second, i.e. 30° in _____ seconds, or 45° in _____ seconds.       

 

14.- Required heading change is 10°: maximum bank angle should be _____°. For a heading change of 5°, bank angle _____°

 

15.- During a large turn, maximum bank angle should be _____° or _____ whichever comes first.      

 

16.- Assuming partial panel operations, and assuming that you must pick up the following headings, state whether you should stop the turn on the required heading, before it or after it: 090°, 130°, 060°, 330°, 270°, 240°.

 

17.- Assuming partial panel operations, and assuming that you must change the airspeed, the magnetic compass reading will deviate towards the _____ during a speed increase, towards the _____ during a speed decrease, except when flying along: a) the North-South axis, b) the East-West axis.

 

18.- The ADI shows a bank to the right but you sense a bank to the left. You must always believe the indications of the ADI and react accordingly. True or false?

 

19.- State the three conditions which are required to crosscheck the D.G. with the magnetic compass.           

 

20.- During all phases of flight requiring constant altitude, constant heading or constant speed, the maximum deviations of these parameters should not exceed: + ______ ft,

+ _____° + _____ kts.         

 

21.- The VSI reading is directly controlled by: a) the elevator  input, b) the trim input, c) the power setting.           

 

22.- The ASI reading is directly controlled by: a) the elevator input, b) the trim input, c) the power setting.           

 

23.- Assuming the following speeds, state the approximate bank angles to obtain rate 1: 60 kts, 100 kts, 140 kts.         

 

24.- In which case is VA required?          

 

25.- The rate of descent is 500 ft/min. In order to level off at 2000 ft, the procedure should gently be initiated when passing _____ ft.  

 

26.- The rate of climb is 1200 ft/min. In order to level off at 2000 ft, the procedure should gently be initiated when passing _____ ft.  

 

27.- During full panel operations, the _____ is the most important instrument for pitch and bank.        

 

28.- The vacuum pump has failed: the most important instruments are the _____ for pitch control and the _____ for bank control.      

 

29.- On your training aircraft, assuming climb, or slow cruise, the ball has a tendency to deflect to: a) the left, b) the right.

 

30.- Considering an instrument takeoff, the primary instrument during the groundroll is the _______________; as soon as rotation is initiated, the primary instrument becomes the _______________.

 

31.- Due to an unusual attitude, you notice the airspeed increasing alarmingly:

- 1st action ________________________

- 2nd action _______________________

- 3rd action ________________________

 

32.- Due to an unusual attitude, you notice the airspeed decreasing alarmingly:

- 1st action ________________________

- 2nd action _______________________

- 3rd action ________________________

 

33.- Assuming a vacuum pump failure and an ensuing unusual attitude, explain how you should handle the elevator inputs. Why is this caution required?

 

34.- The D.G. is unserviceable. You wish to perform a heading change of 30°. How would you do that, using the timed turn procedure? And for a heading change of 45°? Of 180°? Of 270°?  

 

35.- Gimbal error is typical for the: a) attitude indicator, b) directional gyro, c) turn-and-bank, d) turn coordinator, e) all gyroscopic instruments.

 

36.- Acceleration/deceleration errors can affect the: a) attitude indicator, b) D.G., c) turn-and-bank, d) turn coordinator, e) all gyroscopic instruments.         

 

37.- How can you verify whether a turn-and-bank or a turn coordinator, is properly calibrated?

 

38.- Except for the dial presentation, there is no difference in indications between a turn-and-bank and a turn coordinator. True or false?

 

39.- What do you understand by magnetic dip? How is it prevented from affecting the magnetic compass needle?

 

40.- Which magnetic compass errors are resulting from the magnetic dip?

 

41.- Light aircraft attitude indicators are restricted:       

- in pitch angle: a) 30°-40° b) 60°-70°, c) 100°-110°    

- in bank angle: a) 30°-40° b) 60°-70°, c) 100°-110°   

 

For further review, refer to PILOT NOTES VII, VIII and IX.