Originally Posted by
Lead Balloon
Believe it or not, the spare engines were bolted to the wing. I think the 707 had the same 'hardware'?
73s? No so much...
Correct. There are more than a few pics around the internet of 707s carrying a fifth pod, they had a cone that fit the front of the engine, presumably to reduce buffeting, which 747 Pilots I've spoken to over the years said was substantial on 747s.
From memory I think one of the photos that pops up often if you do a search is of a Qantas 707-338C in the V-Jet livery at Frankfurt with a 5th pod. Same location as 747, inboard of #2 Engine.