Power-on descent stages and steepening
Descent types:
- Power-on (power assisted): more control of descent path. Normal choice.
- Power-off: a glide.
Most routine descents and approaches to landing are power assisted:
- Control rate of descent for passenger comfort.
- Meet speed and spacing demands of circuit procedures.
Stages of a planned power-on descent to landing (entry from cruise: climb-descent-entry):
| Stage | Action |
|---|---|
| Approaching the destination | Reduce power further: descent at reduced airspeed |
| Final approach | Set power for desired rate of descent while holding recommended approach-to-landing airspeed |
Steepening the descent (normal glide angle too flat for many uses, e.g. clearing an obstacle on approach):
| Means | Effect |
|---|---|
| Flaps | More flap extended = steeper angle for a given airspeed |
| Retractable gear | Extending it steepens angle of descent |
| Forward slip (bank, opposite rudder stopping the turn) | More descent rate without more airspeed, engine idling. Essential with no flaps. With flaps: only if AFM allows slipping with flaps extended |
- Steep obstacle-clearance approach usually needs full flap and lower-than-normal approach airspeed per Aircraft Flight Manual.
Trap: "power-on descent" is not one setting: reduce power approaching the airport, then set final-approach power holding approach airspeed.
References
- TP 1102 Ex.8 Descending
- TP 1102 Ex.15 Slipping