Objectives
To teach the student to:
- achieve specific cruise-power settings using the throttle, propeller and mixture controls for various conditions, as recommended in the Pilot Operating Handbook
- apply any additional measures recommended by the manufacturer with respect to aeroplane configuration or other considerations.
Motivation
The majority of flight time is spent in cruise flight. In order to obtain optimum performance, the pilot must know how to configure the aeroplane properly.
Essential Background Knowledge
Explain:
- cruise performance charts in the POH
- manifold pressure/RPM relationship and the correct use of related controls
- power and airspeed relationship, using the formula: “1 inch MP = approximately 5 Kts”
Advice to Instructors
Before the initial flight, ensure that the student is familiar with the relevant procedures, either through demonstration in the aeroplane, a simulator or through discussion.
The student must be able to fly and trim the aeroplane for level flight or difficulties may be experienced on future flights. A good exercise for straight and level flight is to have the student reduce manifold pressure 1 inch at a time and note the speed change and re-trim while maintaining level flight.
When teaching propeller synchronization, exaggerate the unsynchronized condition to allow the student to recognize it. Have the student practice synchronizing the propellers solely by sound.
Emphasize that after levelling off, the aeroplane must be allowed to accelerate to cruise speed prior to setting cruise power.
Emphasize the importance of monitoring all engine instruments.
Discuss cold weather operations, especially if the student is training during warmer months. Consideration should be given to propeller cycling, monitoring engine gauges and cowl flap operation. For those training during cooler periods of the year, warm weather operations must be discussed. Consideration should be given to performance at higher density altitudes.
Explain the operation of the autopilot, if the aeroplane is equipped with one. During flight, allow the student to operate the autopilot.
As this is one of the first air exercises taught, emphasize the need for a good lookout. Students and instructors must maintain a good lookout during this and subsequent air exercises.
Instruction and Student Practice
Monitor the student closely before and during the level-off. Because multi-engine aeroplanes have a higher rate-of-climb, the level-off procedure will have to be started earlier. Firm control inputs will be required at this time, as the aeroplane will accelerate to cruise speed quickly. Trimming the aeroplane during the level-off may be required.
Have the student set cruise power in accordance with the POH. These settings may be determined prior to flight or upon reaching cruise altitude.
Synchronize the propellers.
Have the student practice increasing and decreasing airspeed by making appropriate power changes. Concentrate on altitude and heading control and trim adjustment. Good airmanship must prevail to prevent shock cooling or other engine damage when reducing power settings. This is especially important with turbocharged engines and with any engine during cold weather.
Emphasize the importance of trimming the aeroplane. The use of aileron and rudder trim, in addition to elevator trim, may be new to the student. Demonstrate the use of the electric trim if the aeroplane is so equipped.
Have the student use the checklist to complete the level-off items.