I speak as a pilot who has flown Performace "A" aircraft since 1962 in my day job (3 and 4 engined). I also speak as a pilot who owns a PA-28 Warrior.
You are all banging on about about the ability of an aircraft to get airborne at a given weight from a runway of a given length. That is only part of the equation. Some of you have introduced a discussion about pressure altitude etc.
What you are driving towards is a WAT limit. WAT= (Weight/Altitude/Temperature).
That limit basically means that your aircraft can get airborne in the runway available but will be unable to climb after take-off if exceeded.
I can remember meeting one of my old friends in Sharjah in the 1970s. He had just got airborne that day (and I stress the word "just") in a Victor MK.1 tanker from Dubai and they had raised sand across the desert for 3 miles much to the chagrin of Dubai ATC!
He asked me why this should be because their "take-off performance graph" showed that they had runway to spare.
I explained that it was perfectly possible to get airborne from a runway but then be unable to climb due to the fact that the weight or the temperature or the altitude of the airfeild was too high.
All that Bomber Command had was a TORR (take off run required) graph and stopwatch acceleration points.
I go to Sandown frequently with my Warrior and I would be quite bothered about getting out of there in zero wind with four on board at 30°C and with any sort of fuel at all.
I hasten to add that I have no experience of flying a PA28-140.
Last edited by JW411; 7th Aug 2007 at 20:39.