Originally Posted by
tuna hp
Eh, I'm pretty sure that the 7X has better runway performance than any of its long range competitors.
First consider that its 3 engines instead of 2, so as far as determining takeoff requirements, you only lose 1/3 of power instead of 1/2. Also, I'm pretty sure that twinjets have to take off over an assumed 50 ft obstacle whereas for some reason trijet regulations state the it only has to get off the runway.
Secondly, the Falcons have more aggressive high lift devices than the gulfstreams. Gulfstream brags about not having forward high lift devices? Why? It seems to me there's a reason why they're common... allow you to better optimize the wing for both high altitude cruise and takeoff...
So it makes sense to me that they would be competitive as far as runway requirements, even with lower power to weight ratio. In fact, considering that to get X total thrust out of 3 engines is less efficient than getting the same X thrust out of 2 engines, the plane better have lower power to weight ratio or it would have much worse fuel consumption to weight ratio.
I will take the pepsi challenge on runway numbers with a 550 and a 7x...
Losing only 1/3 of the power on a 3 engine plane and 1/2 the power on a 2 engine plane is not accurate. 2 engine aircraft have much more power out of each engine, thus the need for only 2. I think you'd be surprised to see actual numbers with your statement!
Falcon 7x engine makes 6100 lbs thrust x3= 18300... x2=12200. G550 engines make 15385 each, x2=30,770. Single engine, the 550 makes more than the 7x (bigger plane, but you see the difference is about nil). Dont buy into falcon's "3 engines are safer" BS that they have been trying for years! They make a great plane, dont get me wrong! However they used to raz gulfstreams by saying "winglets are a product of poor aerodynamic design"... Now all new falcons have winglets
The 550 wing is *incredibly* efficient. Able to cruise up to .89, with a normal cruise of .85 (everyday), and a typical ref speed in the very low 100's-- all with no leading edge devices. The less moving parts, the less ****** breaks!
-spike