Sir - I read the article "DGPS approaches" (Flight International, 28 February-5 March, P28). Latlong developed software in1988, which allows its creator, T Peter Cutsey, to design a flyable "pseudo" approach to any airport, tailor-made for the aircraft type in question.
In the US Federal Aviation Administration's Special Category 1, based on DO-217, there exists the capability for the use of up-linked way-points to create "pseudo" approaches. The FAA (quite rightly) has disallowed this, because of the variables met in each approach. Thus, co-ordinates from one, or even several, approaches should never be considered in the creation of any curved approach.
Capt T PETER CUTSEY
President
Latlong
Indian Wells, California, USA
Source: Flight International
