GM2 to AMC13 ATS.TR.210(a)(3) Operation of air traffic control service

HELICOPTER TAXI OPERATIONS

(a)The provisions in points (b) to (f) may be considered and applied when wheeled helicopters or vertical take-off and landing (VTOL) aircraft taxi on the surface.

(b)Ground taxiing uses less fuel than air-taxiing and minimises air turbulence. However, under certain conditions, such as rough, soft or uneven terrain, it may become necessary to air-taxi for safety considerations. Helicopters with articulating rotors (usually designs with three or more main rotor blades) are subject to ‘ground resonance’ and may, on rare occasions, suddenly lift off the ground to avoid severe damage or destruction.

(c)When it is requested or necessary for a helicopter to proceed at a slow speed above the surface, normally below 37 km/h (20 kt) and in ground effect, air-taxiing may be authorised.

(d)Instructions which require small aircraft or helicopters to taxi in close proximity to taxiing helicopters should be avoided and consideration should be given to the effect of turbulence from taxiing helicopters on arriving and departing light aircraft.

(e)A frequency change should not be issued to single-pilot helicopters hovering or air-taxiing. Whenever possible, control instructions from the next air traffic services unit should be relayed as necessary until the pilot is able to change frequency.

(f)Most light helicopters are flown by one pilot and require the constant use of both hands and feet to maintain control during low-altitude/low-level flight. Although flight control friction devices assist the pilot, changing frequency near the ground could result in inadvertent ground contact and consequent loss of control