Originally Posted by
dixi188
ISTR that BA had the same powerplant on the 747-436 and the 767-236. RB211-524
The RB211-524 engine was indeed common between the 767 and the 747-400 installation - in general the only change needed was to 'rerate' the engine (simple replacement of the rating plug on the fuel control, not so simple paperwork trail).
But that was not uncommon. Both the CF6-80C2 FADEC and the PW4000/94" were common between the 767 and 747-400 - again with the proviso that you needed to change the rating plugs.
When you have a common engine, it's easy to make the engine/aircraft interface common between two airframes.
However it's a much different story when you have a common airframe and want to fit dissimilar engines.
BTW silton - that's my recollection as well. Both the initial Eastern and BA 757s had the RB211-535C engines - Rolls later introduced the RB211-535E4 engine in response to the Pratt PW2000. The 535E4 incorporated wide-cord blades and had a big fuel burn improvement relative to the 535C engine. Again, keeping the engine/aircraft interface consistent was relatively easy given it was a design requirement for the 535E4 engine and the interface differences between the 535C and E4 variants was minor.