Exercise 7 - Autorotation 1

GROUND SCHOOL POINTS

  1. Theory of autorotation
  2. Distribution of the autorotative force
  3. Autorotative performance
  4. Rate of descent in autorotation

PREPARATORY INSTRUCTION

Aim

For the student to learn how to:

    1. enter autorotation;
    2. descend at the indicated airspeed for minimum rate of descent; and
    3. overshoot to the climb.

Review

Climbs, descents and turns.

Motivation

This is an introduction to autorotation, which is a basic and essential emergency procedure.

Airmanship

    1. Pre-entry checks, to include:
      1. pre-landing check;
      2. lookout, particularly below;
      3. select suitable precautionary landing area; and
      4. verbal warning.
    2. Post-entry checks as appropriate to type.
    3. Aircraft performance limitations, specifically rotor RPM.

Teaching Points

    1. Explain that the helicopter is fully manoeuvrable in autorotation.
    2. State the manufacturer's Indicated Airspeed and rotor RPM for minimum rate of descent in autorotation.
    3. Describe the entry as follows:
      1. at a safe altitude, straight and level cruise, into wind, over a suitable area, complete airmanship checks;
      2. lower collective;
      3. use throttle to prevent overspeed, as appropriate to type;
      4. when collective is fully down, split needles and select recommended engine RPM; and
      5. prevent yaw.
    4. Explain that:
      1. heading and airspeed are controlled with cyclic, as in powered flight; and
      2. rotor RPM is controlled by collective.
    5. Point out that turns in autorotation increase the rate of descent and rotor RPM.
    6. Point out that it is advantageous to roll out as soon as possible in order to reduce the rate of descent, and to simplify the flare prior to landing.
    7. Describe the overshoot as follows:
      1. at a safe altitude, rejoin the needles, using the throttle as appropriate to type;
      2. apply climb power;
      3. select or maintain climb airspeed; and
      4. prevent yaw.
    8. Explain that whereas reaction has to be quick in the event of an actual engine failure, the accent during this introduction will be on smoothness and accuracy.

PRE-FLIGHT BRIEFING

AIR LESSON
    1. Demonstrate a straight-ahead autorotation with overshoot to the climb.
    2. Student practice.
    3. Demonstrate 90, 180 and 360° autorotations with overshoot to the climb. Point out increased rotor RPM and rate of descent.
    4. Student practice.
    5. Demonstrate an autorotational landing.

POST-FLIGHT DEBRIEFING

TIPS FOR INSTRUCTORS
    1. Ground presentations and air demonstrations should make the point that autorotations need not be a stressful or frightening manoeuvre.
    2. A low cloud base will cause demonstrations to be rushed. Fly this exercise in conditions that will allow sufficient altitude to make the demonstrations effective.
    3. Encourage students that throughout the course they will practise autorotations until they are totally proficient and their actions become second nature.
    4. It should be noted that this exercise is to familiarize students with autorotation, not to unnerve them. Keep demonstrations and attitudes gentle until confidence is acquired.
    5. Most schools have approved areas for all autorotational exercises and only practise them dual. Be sure that your students are aware of the school policy.
    6. It is a good practice to introduce this exercise at altitude, (at least 2000 feet AGL), to demonstrate the characteristics and the recovery from autorotation, before positioning the student close to the ground. This generally helps to build students' confidence as the ground is not "rushing up" at them in the middle of the power recovery.