N712PA a JT3 engined 707 from Pan Am's initial 6 lost the No 4 engine over France on 25th February 1959 in a training incident, it landed at Heathrow and was repaired in the Pan Am hangar.
N712PA had been involved in a near 30,000 ft dive over the Atlantic three weeks earlier where it got close to Mach1...possible autopilot malfunction ..... No 3 dos'nt look to clever either!! ..... nobody checked the engine mounts?.