haha.. yes thats true. Its on a speed to fly chart which gives you V2+20. I'm trying to get that one out of the CIC too.
Standby caller, your call is important to us, please hold..
Its surprising how hard it is to let go of an idea that is deeply held, no matter how much evidence there is to the contrary..
retracting flaps at 400 feet is a myth. Flaps do not - never have - cared how high they are. Flaps retract with speed and to maintain the manufacturers published gradients we should do them when the manufacturer says. For aircraft I have flown that is V2+10, V2+11, and V2+20. Flaps reduce the take off speed and therefore the tyre speed, they mean we get airborne in a shorter ground roll, they mean we have less energy to lose in the event of a critical engine failure before V1. But the great myth of perf A and of the way we are taught during type ratings is that they somehow make the aircraft fly better once airborne. We very quickly (all engines operating) pass the speed where they are useful and the lift to drag curve of the clean wing surpasses the performance of the wing when its flapped. Nobody explains this because it isnt the critical case but it leads to a lot of misunderstanding (as can be seen from the number of people telling me I'm up for a darwin award and don't know what I'm talking about). Truth is this misunderstanding leads to an awful lot of confusion - there are people flying medium and heavy business jets who have posted on here who simply haven't got a clue what to do if an engine fails after flap retraction in the climb. Some hold whatever speed they have, some pitch up to slow down to a speed where they can take flap again and climb with that - some have honestly never thought about it. Pilots think that the 400 feet one engine inoperative certification criteria where the powerplant fails at V1 is a limit which should be imposed on all take offs. Some think you need to climb to 1500 feet with the flaps. This amazing mixture of duff knowledge has come from compressed teaching and from tribal knowledge passed from pilot to pilot. Its utter, utter rubbish.
The manufacturer (all manufacturers) publish the way their aircraft should be flown and the way they will perform if you do what they say. Very few pilots read or understand this information. As a result, the benefits of flying as per the AFM are lost. The pilot of the G4 who doesn't know the difference between predicating a departure on two engine climb data and using one engine inoperative climb data has shown just how serious this issue is. We lose the extra safety margins of operating as the manufacturer intended, we create more noise, we burn more fuel, and when the day comes where the powerplant fails at a time other than the one we planned for, confusion will reign. Ask your colleagues what they think they should do when they they lose a powerplant at 500 feet in the climb, see if all the pilots you fly with know exactly what to do. I almost guarantee you will get a worrying array of answers..
Last edited by tommoutrie; 27th Nov 2012 at 08:07.