Thank you so much for your answer and direction to the turboprop-powered DC-3, Monsieur Discorde! Proof positive of your CG argument. Though the development of the Viscount in the late 1940's did, in fact, briefly feature reciprocating piston engines, that variant was never built. Viscount was a turboprop - and even turbojet - engined beast from its inception.
One thinks that the extra-long nacelles and associated structural members might impose a significant torque penalty on the main spar mounts, especially during flight through turbulence and high power settings. One wonders why Vickers' aerodynamicists did not simply move the wing a foot or two forward to alleviate this potential problem by shortening nacelle length. I ponder the Lockheed L-188 Electra's whirl mode failures, from which the venerable Viscount never suffered.
Perhaps it was all a case of "Nacelle Envy"?
- Ed
