Ex. 23 Advanced Take-Off, Landings & Transitions

When taking off into wind we know that the power reduction gained by being in ground effect, although lost as we accelerate will be offset by the onset of translational lift.

If the Flight manual specifies crosswind or tailwind limits then these must not be exceeded.
Often the flight manual will not state limits, it will however state wind velocities which have been demonstrated and to which the machine is capable of being flown.
Clearly even if not stated the helicopter will have physical limits of wind strengths, beyond which at certain azimuths it would become uncontrollable.

On arriving at an off airfield landing site, we need to ascertain if a safe approach can be made into that site. We do this by first flying a high reconnaisance of the site noting some distant landmarks which we can use as markers if we become disorientated and lose sight of site. This high recce is normally carried out at about 1000ft AGL, clearly nearby airspace, a site on high ground or near (not in) a built up area may limit our options as to altitude and ground track during the recce. During the recce we use the 5s mnemonic to remind ourselves of the items we need to check as we orbit the site.

• Size - Is It Big Enough
• Shape - At least one long axis is beneficial, like a football pitch
• Slope - The flatter the better, limited power techniques would be difficult on a slope, and slope limits may reached in extreme cases.
• Surroundings - A site surrounded by obstacle gives us a further consideration, tall obstacles may steepen our approach.
• Surface - Grass and concrete are good, tall crop or heavily rutted fields are bad. Easily moved surfaces like sand require caution