Objectives
To teach:
- recognition of the symptoms of an approaching stall
- recognition of power-off stalls in both the landing and cruise configurations
- positive and smooth recovery, while maintaining directional control, with a minimum loss of altitude
Motivation
The handling characteristics of the multi-engine aeroplane during the stall and on the subsequent recovery can be considerably different from those of single engine aeroplanes. Additional items such as landing gear and propeller add to the pilot's workload. Pilots must be able to recognize the approach to the stall and the stall itself, and then initiate correct recovery procedures.
Essential Background Knowledge
Review basic stall theory:
- aerodynamics
- adverse flight characteristics
- effect of power
- effect of Weight and balance
- entry, recognition and recovery
Explain:
- effects of landing gear and flap
- asymmetric power
- VMC considerations
Advice to Instructors
All stalls must be entered from power-off straight and level flight with slow deceleration, in accordance with the POH/AFM. Power-on stalls are to be avoided. Using power on the entry can lead to an inadvertent spin entry, from which recovery may be difficult and result in substantial loss of altitude.
Trimming the aeroplane during the stall entry can lead to control difficulties on recovery, especially with full power application. The trim should be set for an airspeed that is not slower than VYSE.
The aeroplane is to be fully stalled in the clean configuration for this exercise.
Some POHs may not list a stall recovery procedure. In such a case, stall recoveries should be in accordance with the Flight Training Manual. Following the initial stall recovery, drag can be eliminated and the aeroplane returned to the cruise or climb configuration in the same way as described in the overshoot procedure for the aeroplane.
The sequence for landing gear and flap retraction may vary among aeroplane types; consult the POH/AFM for the correct recovery procedures.
Inadvertent spin entry is possible during practice of this exercise. If a wing drops at the point of the stall, or if one engine responds faster than the other while the speed is below VMC, the aeroplane will yaw and roll and may become uncontrollable. In these situations, verify power is at idle for both engines and do not apply power again until the airspeed is above VMC. Review the spin recovery procedure for the aeroplane type.
Instruction and Student Practice
Ensure that all appropriate safety checks have been completed prior to initiating this exercise.
Conduct this exercise at an operationally safe altitude that will allow for the recovery to be completed at or above the height specified by the manufacturer, or no less than 3,000 feet above ground, whichever is greater.
Demonstrate and allow the student to practice stalls in various configurations:
- landing gear retracted - flaps retracted
- landing gear extended - flaps retracted
- landing gear extended - flaps extended
Emphasize during stall training:
- prevention
- recognition
- effective recovery with a minimum loss of altitude
- maintaining directional control
AVOID SLAMMING THE THROTTLES, advance throttles smoothly to ensure that both engines respond evenly.