Originally Posted by
olster
Surely the PAPIs are aligned with eye height. Therefore they are bound to have different clearance limits depending on whether you are flying a 737/747 or a light aircraft. The problem compounds when you are teaching future airline pilots to land a typical light aircraft abeam the PAPIs hence using up considerable runway behind you. It is obviously important to be disciplined with touchdown aiming points when flying swept wing jet transports with finely calculated landing performance versus plonking it down on the numbers in a general aviation machine. Incidentally even in airline world we teach to ignore the PAPIs below 200 feet (within reason!). Interesting debate though.
Your point is valid, however you could equally consider that you´ve got plenty of runway ahead of you, on an airfield that is equipped with PAPIs, when you arrive in the typical light aircraft. Whatever the aircraft performance handbook is based on, is ultimately going to be a good argument to follow.