How "similar" are the Rolls Royce Conway RCo.12 Mk 508's that powered the 707-420 to the RCo.43 Mk 550's of the Super VC-10? In other words, if you listen to a VC-10 operating today, is that sound likely to be indicative of the sound produced by the Mk 508 variant that powered the 707-420?
Photo © Keith Bradley
Photo © Roland Cartarius
I realize that the sounds may be nothing at all alike, since the Mk 508's produced something like 17,500 lbs of thrust while the Mk 550's of the VC-10 put out well over 20,000 lbs. Yet -- and here's my tenuous linking of the two -- they are both Conways.
How I would love to know!
(BTW, a complete listing of the RCo. variants can be seen here.)