Maximum surface gradients for aircraft?

[Guest Dominik Mann]

I know many of you will consider this an odd question, but I was wondering about the following. I am aware, of course, that airplanes do not have powered wheels and rely only on their thrust engines - prop or jet - for propulsion, but does the power of these engines suffice to propel an airplane weighing several dozen or even hundred tons along an upward slope? I know that British and Russian carrier aircraft take off from "ski jump" ramps incorporated in the ships' decks without the assistance of catapults, but can heavy commercial aircraft with their lower power to weight ratio negotiate rising surface gradients as well, and if so, to what extent?Thanks to all of you!

[Guest emergency_pants]

Heavy commercial aircraft? Well... at a guess, I would think that there is a mathematical point where the thrust power of the engines will no longer move the weight of the aircraft. I don't know the calc off the top of my head but it would be a calculation involving engine power, aircraft weight/inertia, gradient/gravity, inertia.The engines are no longer simply pushing the plane forward, but upwards also.Yikes... could be a mathematical nightmare! LOLIn theory though, all you'll need to take off on a gradient is a longer runway, because acceleration would be lower. You'll reach takeoff speed eventually, but it'll take longer.Not sure if this is likely to help, but you might find a calculation on a good engineering/physics site, I would imagine.

[Guest]

yes,there is a maximum:every maximum is depicted on the aircraft operating manual

[Guest Jimbofly]

Heavy commercial aircraft such as the Boeing 747 can actually accelerate at up to a 15 degree pitch up attitude! Such an aircraft will accelerate up to about 230 knots or so in the climb.So in answer to your question, yes, heavy commercial aircraft can accelerate up a gradient.James