Aircraft Operations

I-8-2-2
Procedures — Aircraft Operations — Volume I
aerodrome” NDB or VOR procedure). In these cases (if the FAF to MAPt distance exceeds certain values
dependent on aerodrome elevation), a slower speed when combined with a tailwind may cause the helicopter to
reach start of climb (SOC) after the point calculated for Category A aeroplanes. This will reduce the obstacle
clearance in the missed approach phase. Conversely, a slower speed combined with a headwind could cause the
helicopter to reach the MAPt and any subsequent turn altitude before the point calculated for Category A
aeroplanes, and hence depart outside the protected area. Therefore, for helicopters, speed should be reduced
below 130 km/h (70 kt) only after the visual references necessary for landing have been acquired and the
decision has been made that an instrument missed approach procedure will not be performed.
b) Rate of descent after fixes. When obstacles are close to final approach or stepdown fixes, they are discounted for
Category A aircraft if they lie below a 15 per cent plane relative to the earliest point defined by the fix tolerance
area and minimum obstacle clearance (MOC). Helicopters are capable of nominal descent gradients which
could penetrate this plane. Therefore, for helicopters, rates of descent after crossing the final approach and any
stepdown fix should be limited accordingly.
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23/11/06