PAPI - How low can you go?
 

Just as general interest and back ground but: how low are PAPI guidance lights supposed to take you? I have found in manufacturers blurb info suggesting that following 2R 2W down to as close as 300yds and roughly 15m to be accurate that, for a large aircraft doesn't seem feasible. From MDA/DA (substitute H as required) you're "in the groove" and at some in defined point transition to some sort of flare and landing attitude is going to happen such that you arrive on the black top in the touchdown zone. Crossing the threshold at a nominal 50' of course when you're main wheels are some 34 FT below you and perhaps the receiver aerial for the ILS and you're view of the PAPIs don't all match up......
Standing by for criticism for not knowing the answer
But also hopeful of some good he.......:confused:

Well they don't have any regulatory minimums of course - but I guess you know that. As for how low are they accurate, I think it is down to the published MEHT (Minimum eye height threshold).

MEHT
 

Absolutely yes but can't find the published one for the airfield in question. Also it will depend upon the type, size and attitude/configuration of the aircraft. What works say for a fast jet won't for a big turbo prop or a lifting body style airliner. All size wise dissimilar and pilots eye height to aerial position incomparable. Seems very much that one set of lights won't fit all unless using all available clues they are as much a guide as a Precision approach path indicator....

PAPI
 

Take a look at this thread http://www.pprune.org/tech-log/56301...ow-300-ft.html

Brilliant, thanks...just what I was looking for and hadn't realised it was there. Just too old to be a fan of the search facility to my eternal shame obviously...:ok: