Exercise 4 - Air Speed and Power Changes - Straight and Level Flight

GROUND SCHOOL POINTS

Flight Manual - engine, transmission and airspeed limitations.

PREPARATORY INSTRUCTION

AIM

For the student to learn:

    1. The relationship of rotor disc and fuselage attitudes to indicated airspeed.
    2. The correct methods of selecting or changing engine power, e.g. manifold pressure and rotor r.p.m.
    3. How to fly straight and level in balanced flight at selected airspeeds or power settings.

Review

Exercise 3 - Effects of Controls.

Motivation

Airspeed and power changes form the basis of all helicopter flying and they must be performed smoothly and accurately.

Airmanship

    1. Lookout.
    2. Engine and transmission limitations.

Teaching Points

    1. Airspeed Changes
      1. Explain how a reduction in speed from the cruise to a specific airspeed is effected (e.g. from 70 kt to 50 kt):
        1. cyclic aft to raise the nose of the aircraft
        2. pause whilst airspeed stabilizes
        3. adjust airspeed as necessary.
      2. Explain the method of accelerating to a specific airspeed:
        1. cyclic forward to lower the nose of the aircraft
        2. pause while airspeed stabilizes
        3. adjust airspeed as necessary.
      3. Point out that cyclic movements should be small and made smoothly. Large or hurried movements should be avoided.
    2. Power Changes
      1. Describe the relationship between collective and throttle movement as appropriate to type.
      2. Describe the effect that power changes have on balanced flight due to torque changes.
      3. Where appropriate, describe the methods of:
        1. changing manifold pressure at constant rotor RPM, and
        2. changing rotor RPM at constant manifold pressure.
    3. Straight and Level Flight
      1. Explain that straight and level flight means flight at a constant altitude and heading.
      2. Describe the power and airspeed settings used for straight and level cruising flight as appropriate to type.
      3. Describe how to maintain airspeed at a constant altitude and heading using visual and instrument cues such as the relationship between the disc and the horizon, airspeed indicator, altimeter, etc.
      4. Explain that when flying at a specific airspeed, altitude corrections are controlled with the collective, and when flying at a specific power setting, corrections are made with cyclic.
      5. Describe how to reduce airspeed in straight and level flight:
        1. Select a slightly higher nose attitude (cyclic aft)
        2. Reduce power to prevent climbing (collective/throttle)
        3. Prevent yaw (pedals)
        4. Pause, to allow airspeed to stabilize.
        5. Adjust power and airspeed as required.
      6. Describe how to increase airspeed in straight and level flight:
        1. Select a slightly lower nose attitude (cyclic forward)
        2. Increase power to prevent sink (collective/throttle)
        3. Prevent yaw (pedals)
        4. Pause, to allow airspeed to stabilize
        5. Adjust power and airspeed as required.

Confirmation

PRE-FLIGHT BRIEFING

AIR LESSON
    1. Review previous air lesson
    2. Demonstrate airspeed changes
    3. Student practice
    4. Demonstrate power changes
    5. Student practice
    6. Demonstrate straight and level flight at cruise power
    7. Student practice
    8. Demonstrate changes of airspeed in straight and level flight
    9. Student practice
    10. Briefly let the student attempt to hover at the conclusion of each exercise until completion of Exercise 8.

POST-FLIGHT DEBRIEFING

TIPS FOR INSTRUCTORS
    1. See 1 in previous exercise.
    2. Students will often tend to pay much attention to the flight instruments in this exercise. Care must be taken to ensure that a proper scan between the instruments and external references is established and that a good lookout is maintained.
    3. Changes of airspeed during the early stages of this air lesson will result in changes of altitude. It is important therefore, to conduct this lesson at 1,000 feet AGL or more, and in good weather conditions, to avoid the nearness of obstacles distracting the student.
    4. Changing airspeed at constant altitude and heading is a useful co-ordination exercise that can be reviewed at various stages through the training course.
Date modified: