When Orange extended it's runway to allow for the F100 over the Saab, we moved the PAPIs about 20m. "The standard wheel clearance over the threshold for the most demanding amongst the aircraft regularly using the runway"
RAAF Base Williamtown has long been the home of fighter squadrons of the RAAF and is used by civilian aircraft. The current Air Services aerodrome chart reveals runways 12/30 have a PAPI set for a three degree slope with threshold crossing height of 50 feet.
From observation the crossing height of most jet fighters operating from Williamtown seems to be about 10 feet with aiming point to touch down very close to the runway threshold markers. Assuming therefore that "the standard wheel clearance over the threshold for the most demanding amongst the aircraft
regularly using the runway and fighters use the Williamtown runways a lot more than civil arrivals, how come the PAPI is not set at ten feet over the threshold rather than 50 feet?
