Part II — The Ground and Air Instruction Syllabus — Exercise 8 — Descending


To teach:

(1)  Descending:

  1. At the recommended power-off descent speed;
  2. At various power settings, airspeeds, and flap/gear configurations to a selected altitude;
  3. On constant path of descent towards a specific point of touch-down;
  4. At the published airspeeds required for an obstacle clearance approach.


As required.

Essential Background Knowledge

(1)  Explain:

  1. Use of Pilot Operating Handbook to determine descent airspeeds;
  2. The need for a proper look-out ahead and below, before and after commencing descent — cockpit checks;
  3. Practical examples in the use of:
  1. power-off descent at various airspeeds;
  2. power-on descent at various airspeeds;
  3. power-off descent for range and how to estimate how far the aircraft can glide;
  4. "en route descents";
  5. obstacle clearance descents.

D. Procedure to descend from level flight (power — attitude — trim) and how to return to cruise attitude;

E. The use of flaps in a descent:

  1. to reduce stall speed;
  2. to steepen angle of descent.

F. How if yaw (due to reduced slipstream effect) is allowed to develop, a roll may result;

G. The effects of wind on gliding distance;

H. How, during a descent at a fixed airspeed, power can be used to adjust the rate of descent;

I. The reasons why and the techniques for warming the engine during a prolonged power-off descent, particularly in cold weather;

J. The use of the carburettor heat in a power-off descent as applicable to various types of training aircraft;

K. Speeds for high angle of descent, low speed approaches

L. How extension of retractable landing gear can be used to steepen the descent of that type of aircraft;

M. Visual indications to detect touch-down point during descents at various speeds and power settings. (See Advice to Instructors);

N. Instrument indications where applicable.

(2)   Question student on the exercise and clarify as necessary.

Advice to Instructors

(1)  This is a progressive exercise, and no attempt should be made to teach all aspects of descending in one lesson. Demonstrate only where applicable, e.g., power-on steep angle descents for short field/obstruction clearance approaches.

(2)  Particular attention must be paid to maintaining engine temperature when descending in cold weather conditions.

(3)  Ensure that the student understands the proper use of visual indications which assist in detecting the touch-down point, while descending at various speeds and power settings.

(4)  A sound knowledge of the principles and considerations of power-off descent is a necessary ingredient of successful forced landings. Give the student ample practice at maintaining the correct airspeed/attitude to ensure proficiency is achieved. Use every opportunity (e.g., when proceeding to and from the practice area) to give practice in estimating how far the aircraft can glide under existing conditions.

(5)  The importance of correct use of carburettor heat and mixture controls prior to and during a descent should be emphasized.

Instruction and Student Practice

(1)  To enter power-off descent:

  1. Establish Cruise Attitude;
  2. Complete cockpit check as necessary;
  3. Look out ahead and below;
  4. Reduce power to idle — keep straight;
  5. Maintain Cruise Attitude until speed approaches recommended power-off descent speed, then place aircraft in appropriate descent attitude;
  6. Trim;
  7. Explain how to judge the distance the aircraft can glide — how speed affects range;
  8. Instrument indications.

(2)  To resume cruise flight at selected altitude and airspeed:

  1. Co-ordinate pitch and power changes;
  2. Keep straight;
  3. Carburettor heat off where applicable;
  4. Re-adjust power/attitude, if necessary, to achieve desired performance;
  5. Trim;
  6. Instrument indications.

(3)  Demonstrate descending:

  1. Power-on:
  1. en route descent;
  2. power approach;
  3. instrument indications.

(4)  Demonstrate descending with various flap settings:

  1. Lower flaps — check correct flap extension speed;
  2. Point out:
  1. as flaps are extended in stages, the increase in angle of descent if same speed is maintained;
  2. safety consideration when raising flaps on return to Cruise Attitude.

C. If retractable landing gear is fitted, demonstrate its effect on the rate of descent — check correct gear extension speed.

(5)  Power-on descents over an obstacle:

  1. Select the appropriate airspeed from the Pilot Operating Handbook;
  2. Show how the correct combinations of attitude and power produce the desired flight path (performance);
  3. Select proper flap settings for configuration desired.

(6)  Instrument indications.

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