Originally Posted by
Wyvernfan
Thanks for the extra info Alan Baker and Dave Reid. I’ve only ever been aware before of the Conway engined version for BOAC / BA.
Boeing stopped offering the Rolls-Royce 707 after 1963, so BOAC, like the others, had to go for the P&W powered version for subsequent orders. Boeing only built 37 of them. Douglas carried on with the Rolls version of the DC-8 for a couple of years longer but then gave up as well. Possibly this was because nobody was ordering any more. The turbofan Rolls had been a popular early type when P&W only offered turbojets, but when they put a fan on the JT3D that reversed the advantage and they took the market. It might have surprised Boeing that BOAC, the principal Rolls purchaser, continued to buy odd 707s, in ones and twos, because all the emphasis was they were only going to buy VC-10s now.
The RR-powered 707 was the same basic airframe as the 707-320, the contemporary P&W JT4A turbojet intercontinental version of the original 707. When Boeing and P&W introduced the turbofan 707-320B they also made a number of airframe changes. Although surely justified, this was also said to have been done to prevent existing 707-320 uses upgrading by just changing the engine - putting the notably more efficient turbofan onto the shorter range 707-120 and 720 had been done without such changes, and a lot of the early production of these types was put through the engine conversion and got a big improvement, to the dismay of Boeing sales teams who wanted to sell whole new aircraft, at a time when the initial big jet changeover orders were now falling away.