Exercise 25 - Confined Areas

From: Transport Canada

PREPARATORY INSTRUCTION

Aim

For the student to learn safe confined area operations.

Review

Advanced Take-offs and Landings - Exercise 24

Motivation

The ability to operate from areas where space is confined and restricted is a basic part of the helicopter's place in aviation. It is vital that a helicopter pilot can take full advantage of this ability.

Airmanship

  • Look-out
  • Wind velocity

Teaching Points

Explain that this exercise can be considered in 6 stages, as follows:

  1. Initial or High Reconnaissance
    1. Point out to students that they must first positively identify the intended landing area. At this initial stage it is wise to carryout a power check, to establish what size of area they can consider.
    2. The initial reconnaissance will generally be flown in a circular pattern to the pilot's side at an airspeed appropriate to the type of aircraft. Height will normally be that at which the student arrives in the area but will generally be 1,000 ft AGL or more. If the student is at 500 ft AGL or less, the initial and low reconnaissance are generally combined, and in fact, with experience this becomes the normal technique.
    3. Three factors should be considered at this stage:
      1. General Suitability - Establish that the confined area is worth closer inspection and that there is no more suitable alternative in the vicinity.
      2. Power Available - The size and difficulty of a confined area varies with the density altitude and AUW/power available.
      3. W/V - An initial assessment of the wind should be made, to be verified later.
  2. Low Reconnaissance
    1. The purpose of the low reconnaissance is to confirm that the area is suitable for the intended operation and to determine the best method of making an approach and landing.
    2. After descending from the initial reconnaissance, the wind should be checked and verified for strength and direction. Smoke, ripples on water, long grass, flags or clothes on a line all give a good indication. The behaviour of the helicopter at fairly low speeds during the low reconnaissance will also give the pilot an accurate picture, due to drift and the tendency for airspeed to fall off when turning downwind.
    3. Factors that the student should take into consideration must include:
      1. Size - Is it big enough?
      2. Shape - Does the shape favour an approach from a particular direction?
      3. Slope - Is the ground level enough for landing?
      4. Surface - What is the surface of the area? Are there snags or obstacles that might obstruct, or a surface that might be a hazard, such as dust, snow or muskeg? Select the touchdown spot.
      5. Surrounds - Do the surrounding obstacles favour an approach from a particular direction?
      6. Sun - Might the sun restrict the pilot's visibility on final approach?
    4. The height and airspeed at which this reconnaissance is carried out will vary. The criteria is that the student can see well enough to make a sound assessment of the approach and landing area. The height should be the maximum compatible with this aim and will vary between 300 and 500 feet above the nearest obstacles. The reconnaissance should be flown to the student's side with the confined area in sight throughout.  
  3. Dummy Approach
    1. During initial training and at any time where the student thinks it necessary or prudent, the actual approach should be preceded with a dummy approach. This should be the same as the intended approach to follow but will terminate with an overshoot at obstacle height.
    2. In situations where the student has not been able to see everything required during the low reconnaissance, the dummy approach can be used to accomplish this purpose and should be flown with the area off to the student's side, to allow maximum visibility. The speed must be slow enough to allow the student to `fill in the blanks' and complete the reconnaissance, but should not drop below the translational lift airspeed of approximately 15 kts.
    3. A power check should be carried-out on the overshoot, and the intended departure path can also be checked at this stage for obstacles, escape routes and any low level turbulence.
    4. From the overshoot the student continues into the circuit, this is normally flown between 300-500 AGL at a slightly slower speed than normal. The size and direction will be governed by terrain, wind and open areas.
  4. Approach
    1. Satisfied with the landing area and the dummy approach, the pilot then continues round the circuit for the approach proper.
    2. The approach angle should never be steeper than necessary. If possible set up the sight picture of the spot over the obstacle. Explain single angle, double angle and vertical approaches.
    3. The approach should be made to a hover over ground that is suitable for landing. Making an approach to hover directly above obstacles, or to a position from which it is difficult or hazardous to manoeuvre, should be avoided.
    4. Accidents are all too frequent during this stage of helicopter operations. The student must be very aware of any obstacles that can snag the landing gear or tail rotor. Turns should normally be about the tail. Make sure that the student manoeuvres only when necessary or to take advantage of the area's size or shape for departure or landing.
  5. Departure
    1. Departures should be initiated from as low a hover as is practicable at the maximum safe distance from the obstacles on the departure path. This gives the student the best power difference in case of emergency.
    2. All departures should be preceded by a power check at the hover. The ideal departure is that which requires least power i.e., at a shallow angle. The pilot must therefore assess whether he can safely clear the obstacles ahead having made a standard departure.
    3. If the obstacles are too high or too near, the vertical or towering departure should be considered.
    4. It requires practice and experience to determine which method should be used, but the student should avoid departure in a manner which will put him close to the obstacles without first having achieved climb speed or at least translational lift.
  6. Aborted Departure
    1. If there is a mechanical failure or similar emergency, or if the pilot makes an error of judgement, he will have to abort. This is a critical manoeuvre and the pilot should remember:
      1. the earlier the decision to abort is made, the easier the recovery; and
      2. that an effort should be made to maintain forward speed and to make co-ordinated turns back to the hover, if at all possible.

Operational Considerations

After the student has achieved competence in confined areas, the instructor should introduce operational considerations in both ground and air instruction. These include:

  1. When carrying out his power check prior to landing in a confined area, the pilot should estimate what the AUW will be when he departs. As a general rule, more power is required for a departure than for an approach, and if power available is found to be limited or marginal during the power check, this factor could be decisive.
  2. A pilot should always be alert to ways of improving a confined area he is using on a continuing basis. He should not be content to work over extended periods in conditions that are difficult, demanding, or even hazardous, unless it is unavoidable. Such things as the removal of trees from the lines of approach and departure, the removal of debris, or the levelling and enlargement of the landing pad whenever possible, will make an operation safer and more effective.
  3. Occasionally an area will require improvement before it can be used at all. A pilot should be able to brief a passenger in the air, during a reconnaissance, pointing out where the necessary improvements should be made. This aspect can be simulated by the instructor during later air instruction.
  4. A pilot should always inspect the general area surrounding the proposed landing site. There might well be an alternate close by that is less confined and therefore easier and safer to use.

Confirmation

PRE-FLIGHT BRIEFING

AIR LESSON 1
  1. Introduce the full confined area procedures using an area that is large enough to permit a "standard" approach and departure.
  2. Student practice to the same confined area.
  3. Student practice to a different confined area of the same size.
  4. Demonstrate the full procedure to a smaller area that requires a steep approach and departure.
  5. Student practice to the same area.
  6. Student practice to other areas of the similar size.
AIR LESSON 2
  1. Demonstrate out-of-wind approaches, taking advantage of shape and surrounds.
  2. Student practice.
  3. Demonstrate aborted departures.
  4. Student practice.
AIR LESSON 3
  1. Student practice at selecting the most suitable confined area in a specific locale

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