Sir - David Learmount's article "Research pinpoints non-precision risks" (Flight International, 6-12 March, P5) on research by the Netherlands National Aerospace Laboratory into non-precision approach and landing procedures puts figures to what has been articulated by air industry for many years.
One aspect of the non-precision approach should be discouraged, however, and that is the practice of a jet-powered aircraft descending early from the final-approach fix and holding level at minimum decision altitude (MDA), while seeking visual reference. This has undoubtedly played a part in non-precision approach accidents in recent years.
To fly level at MDA, in a high drag configuration, with high pitch and high power and seeking visual reference, is a demanding task. It requires pitch and power changes at low altitude and invariably results in an unstabilised final approach, with the possibility of landing short, or being high and fast and landing deep.
Surely it is better to leave the final-approach fix at a pre-calculated rate of descent with the landing-configuration set and make an immediate go-around on reach MDA (or the missed-approach point) if the visual reference cannot be established.
Capt JIM PASSMORE
Head of Safety
British Airways
Hounslow, Middlesex, UK
Source: Flight International
