You want this.

http://www.airliners.net/photo/American-Airlines/Boeing-707-123/0541868/L/

specter177 wrote on Dec 17^th, 2009 at 10:56pm:

C wrote on Dec 18^th, 2009 at 4:14am:


Vicker planes always remind me of this:

http://i50.photobucket.com/albums/f313/JasonFromOz/012_Ajax_cu.jpg
http://i50.photobucket.com/albums/f313/JasonFromOz/017_Ajax.jpg

They haven't solved the asymmetric problem though.

I can tell you exactly why the blended wing concepts have not been pursued, not enough windows.  You would have most of the passengers sitting in the middle of that large aircraft, with only a few of the expected window seats.  Airlines wouldn't buy it.

I believe that's one of the reasons many light twin engined aircraft actually have worse safety records compared to single engined light aircraft. If one engine fails at low speed, the plane will probably crash as the rudder doesn't have enough authority to counteract the torque generated by asymmetric thrust. The solution was to build a physically asymmetrical aircraft, like the Scaled Composites Boomerang. This allows the engines to be spaced much closer together, with the CoG in between them, so an engine failure has only a small impact on flying qualities.



Airliners don't have this problem, however. Only a bigger rudder is required. I wonder if FBW in some aircraft automatically adjusts for an engine out...?



Also, on the flip side... if an engine disintegrates on the VC-10, for example, then it has the possibility of taking out the other engines. If it is anything like the MD-80 (and DC-9), a disintegrating engine is more likely to puncture the pressure vessel (causing rapid decompression, or worse), or injure a passenger (or kill - which has happened before) edit: Of course, the engines could be mounted behind the cabin, but that is likely to waste space and either reduce passenger count, or make the plane longer than it would otherwise need to be, adding weight. Also, wing mounted engines typically counter the bending forces generated by the wings, so more weight is needed with a tail-mounted design.... Lastly, tail mounted designs also need a way to transfer the "force" (for lack of a better word) from the engines to one of the main sources of drag... the wing, this adds even more weight. (and the problems with a tail-mounted design continue...)

The aft (tail) mounted engine on the DC-10 and MD-11 cannot operate on suction (from the engine mounted boost pump) alone, but requires the tank mounted Jettison/Override pumps to be operating. The wing mounted engines on said aircraft can operate from suction alone.

Are all tail-mounted aircraft like this, or only the DC-10 / MD-11?

Thanks.