B-52 with Hound Dogs it is! From 1960, the SAC plumbed and wired some of their B-52s tasked to carry and launch the Hound Dog supersonic cruise missile, so that the Hound Dogs' engines could be run during take-off and climb to altitude, to assist the B-52's eight engines. The missiles' tanks could then be topped off from the bomber's tanks. The Hound Dog had one engine, there were two Hound Dogs per B-52, for a total of 10 jet engines.
However, the Hound Dog's engines were only good for a total of 6 hours' running, so I'm not sure if they were ever actually used in this configuration.
The other aircraft I was thinking of was the Dassault Balzac V. This was an experimental 'proof-of-concept' pre-prototype for the Mirage IIIV. Both had nine engines - eight for lift and one for thrust. The Balzac's thrust engine was a Bristol Orpheus, so it was realy only there for decoration.
One Balzac V was built, and it crashed twice, killing the pilot on both occasions.
The Mirage IIIV was, in theory, capable of Mach 2. Problem was, because the engines were so thirsty, it could either take off conventionally, and achieve Mach 2 (which it did once), or take off vertically, and not. Of course, it could have taken off vertically, done an in-flight refuelling, and then accelerated to Mach 2, but to do that it would have needed to take on fuel from a KC-135, which needs a rather long conventional runway....
There were two prototypes. When the second crashed, the programme was abandoned.
Your turn Jeaton
Cheers,
Chris.
Cute and cuddly, boys, cute and cuddly!