dood.. making it bold and making the text bigger don't make it correct!
Just been on the phone with Flight Safety in Montreal. There is no height restriction in the Bombardier AFM. There is no regulation at all relating to height on an all engines operating take off. As I explained to CLDRVr the reason that the gradient is assured is that by taking the flaps up I am immediately in the final segment climb. With max thrust on the remaining engine its part of the certification that I will maintain the 2.4% (its gross climb by the way not net climb and because theres no level third segment this is easier for me to achieve). Thats without any speculative information about already being well above the required gradient because the failure happened when I'd already been climbing all engines and arguements about take off climb increment because I got airborne earlier than I would have if one had failed at V1. Chaps you have turned what I hoped would be a useful technical discussion into a bit of a personal attack and accusations have been made by Clrdrv and others that I'm doing something out of line with the AFM. I'm absolutely not.
400 feet is a company SOP at Flight Safety and talking to the guy there I don't particularly disagree with their logic (especially for the Challenger) - as he said to me its roughly consistent with V2+20 anyway so why am I worried?
I do, however, think this information is important for aircraft with higher power to weight ratios and wings that are more efficient at lower speeds - the XLS, Soverign, probably the Hawker etc.
If you look at the start of this thread I was discussing pilots leaving flap retraction to some other arbitrary height (400 feet, 1000 feet, 1500 feet, whatever) when a flap retraction height does not exist anywhere in the regulations for all engines operation. The FAR's and the JAR's both refer to the case where the critical powerplant has failed at V1, not the all engines operating case.
I object very strongly to being called a test pilot and a bar practice pilot. Very few on PPrune use their proper names when posting and the anonymity means you can say what you like, you can make up regulations, you can do whatever you want really but I post under my own name because I carefully work through the discussion and stick by what I say. If I'm wrong, post the regulation and that way we all learn (me especially).
If anyone wants to have a proper discussion about this maybe you could give me a call instead - I'm not really interested in a slagging match. I just wanted to really get to the bottom of all this.
Tom +447850 915510