Exercise 8 – Descending
DESCENDING 1: AIR EXERCISE
1. MAINTAINING THE GLIDE
- Not very different to cruise
Glide at Recommended IAS
- Attitude adjustments to control IAS
- Checks – Weave
- – Engine Warm (every 1000 ft)
- (Carb Heat OFF)
- Full Power (for 10 seconds)
- Keep straight – PYR
- Pitch up to climb attitude
- Power to idle (simultaneously PYR, re-select glide attitude)
- (Carb heat ON, A/R)
2. LEVELLING OFF
- Anticipate (50 ft)
- Power – cruise
- Attitude – for level at 70 kts
- Acceleration to cruise IAS (PAAT)
- LOOKOUT – Stress below/behind
- Carb Heat ON (if required)
- Power – Idle, PYR
- Attitude – Maintain initially, at 70 kts select glide attitude
DESCENDING 2: AIR EXERCISE
1. DESCENTS WITH POWER AND WITH FLAP
Effect of power
- From glide descent – check ROD, increase power (200 RPM), maintain attitude: IAS increases
Use of power
- Adjust attitude to restore and maintain IAS, note reduced ROD Increase power in steps of 200 – until descent is arrested Student adjusts attitude to maintain 70 kts
Note reduced ROD and power/ROD relationship
Selected rate of descend
- Student assesses power for given ROD, sets it and controls IAS (70 kts) with attitude
Attitude controls IAS, Power controls ROD
Effect of flap
- From glide descent, select flap in stages maintain attitude: IAS decreases
Use of flap
- From glide descent – check ROD, select flap in stages, Stress Limitation, Operation, Indication (LOI), adjust attitude to restore and maintain IAS (70 kts), note increased ROD and progressively lower nose with successive selections.
Retract flap in stages – maintain IAS.
Flap and power
- Use of flap (10, 20 and full) with power as required to achieve specific descent rates
- Attitude controls IAS, Power controls ROD
2. EMERGENCY DESCENT (STRAIGHT)
- Lookout – ensure descending into a clear area
- Close throttle, Attitude for speed below 85 kts, select full flaps
- Monitor/control IAS carefully (near VFE)
- Not below 1000 ft agl
Select (clean) gliding attitude
- Lookout (above/behind)
- Carb Heat OFF
- Apply full power, PYR
- Retract flap to 20
- Adjust pitch
- Select a shallow climbing attitude
- Retract flap to 10
- Adjust pitch
- “Safe Height/ Speed”, smooth flap retraction, in stages
- Adjust attitude for 70 kts climb
DESCENDING: AMPLIFYING NOTES
- The glide descent is a relatively simple exercise which is taught in the same lesson as Exercise 7 – Climbing; for reasons of efficiency and commonality of some aspects, thereby reinforcing teaching.
- The ability to carry out a glide descent is essential to survival should the (single) engine fail and aircraft can glide without power, is a prerequisite for your student to learn Practice Forced Landings (PFLs). Descents with flap and power which are used regularly in the circuit are taught on the next lesson.
- These notes are in 2 parts: the first deals with the glide descent, the second with descents using flap and power.
THE GLIDE DESCENT
- Preparatory Instruction
1. Best range obtained by gliding at recommended IAS.
2. Effect of wind on gliding range.
3. Engine handling – relation to TEM (below).
THREAT AND ERROR MANAGEMENT
1. Stress the need to ensure the area below is clear before descending and of weaving to lookout during the descent.
2. Emphasize why engine warming at least every 1000 ft of glide is vital.
3. Ensure your student understands and applies the relevant altimeter setting procedures and the implications for terrain clearance of the setting in use.
4. Discuss physiological factors; blocked ears and how to clear them and the dangers of flying with a cold.
1. It is most effective and efficient to begin by teaching how to maintain the descent. Teach the datum gliding attitude and how to adjust attitude to maintain 70 kts. Maintain for 2000 ft or 3000 ft initially for student to learn technique and incorporation of checks. Ensure the student flies in balance and trims both elevator and rudder. Teach weaving every 1000 ft for lookout and the technique for engine warming.
2. Next cover levelling off. Teach your student to anticipate the level-off by 50 ft, to set cruise power (maintaining balance), select the 70 kts level attitude and allow the aeroplane to accelerate to cruise speed (PAAT).
3. Finally, teach the entry, maintaining balance as power is reduced, use of Carb Heat (A/R). Maintain attitude until reaching 75 kts, select gliding attitude, noting the small pitch change from cruise to glide attitude. Stress LOOKOUT before entry (by weaving at this stage or, once Exercise 9 is complete, you can teach the student to turn towards a clear area, if appropriate for the descent).
DESCENTS WITH FLAP AND POWER
- Preparatory Instruction
1. Effect of power on ROD at constant IAS
2. Effect of flap on ROD at constant IAS
3. Power and flap combined to control ROD
THREAT AND ERROR MANAGEMENT
- Stress Limitation, Operation, Indication (LOI) (to comply with VFE) and the importance of maintaining IAS when flap is lowered. More anticipation needed to level off because of a low nose attitude, especially with full flaps.
From a glide descent, note ROD; increase power by 200 RPM and maintain attitude; demonstrate effect: IAS increase. Raise nose to regain 70 kts; note reduced ROD. Teach coordinating power changes with attitude adjustments to maintain airspeed (using power increase increments of 200 RPM) until descent is arrested.
Note: Attitude Controls IAS; Power controls ROD
From a glide descent, note ROD. Select flap in stages maintaining attitude; demonstrate
the effect of IAS decrease. Clean up. From glide teach coordinating attitude
adjustments to maintain airspeed as each stage of flap is lowered.
a. Check below Vfe – Limitation, Operation, Indication (LOI)
b. Marked nose down attitude with full flap – better forward visibility
Note: Attitude Controls IAS; Flap increases ROD
- Flap and Power
1. Teach controlling ROD with power at different flap settings, whilst maintaining specified IAS. Attitude Controls IAS; Power controls ROD
2. A useful guide to the student for power settings is: A change of 100 RPM = a change in ROD of 100 ft/min (at a constant IAS)
3. Because this technique is applied in the circuit, demonstrate its use on the base leg when returning from this lesson, or can be introduced in rectangular course exercise. It is not directly applicable to the final approach, so do not use it with a runway as a
reference feature as this may confuse your student.
- Emergency descend
1. This is merely a special case of descending with flap, used when a rapid, controlled descent is required, applicable to an airborne fire leading to forced landing.
2. Teach the entry (Carb Heat,A/R), throttle closed, full flap (speed limit), attitude to maintain 85 kts.
3. Teach maintaining: straight descent initially, delicate handling (close to VFE); note (high) ROD.
4. Teach to anticipate level-off by 200 ft, retracting flap as IAS decreases; transition to 60 kts (clean) glide. Emergency descents should not normally be continued below 1000 ft. (A possible exception being in the case of a real, unextinguished fire where the earliest possible landing is necessary.)
5. On later lessons, as your student becomes more proficient, teach steep descending turns at 85 kts with full flap (within flaps limit speed). More details are given at Exercise15.
- The Go-Around
1. This is simply a transition from a descent with full or partial flap to a climb. The emphasis of teaching, therefore, should be on flap retraction and transition to a normal climb.
2. You should have demonstrated (during Exercise 4) the sink caused by rapid flap retraction at low speeds. If you haven’t, do it now! Teach your student to check “Safe height, Safe speed” (not less than 60 kts and 200 ft agl) before retracting flap completely in a climb.
3. Teach: Apply full power (preventing yaw, Carb Heat OFF, if applicable). Retract flap to 20°. Select a shallow climbing attitude. Check “Safe Height and Speed”; smooth retraction, in stages, with attitude adjustments as necessary to achieve required IAS. Trim.
- Common Faults
Some students do not allow enough time for the airspeed to stabilize and consequently chase the airspeed.