Re: Jet Engines above the wing: why not used?

From:         Tim Hills <Tim@cordle.demon.co.uk>
Organization: Timbo PLC
Date:         01 May 96 11:19:55 
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>I think that the main reason for underwing poddded engines is ease of
maintainance. An engine change on something like a 747 is relatively
straightforward, as the engines are only a few feet above the ground,
and can be changed in the open air if nescessary.

Also a podded engine is designed to detatch in the event of severe
damage. Amazingly, this has even worked a few times.

Finally, it is aerodynamically  advantagous to have the engine thrust
line below the longditudenal axis, as a power increase will then result
in a nose up pitch. I notice that the USAF finally went for the
conventionally engined C17, although I admit that the YC14/15 were good
looking designs!

--
Tim Hills