In the late 80's a Continental 747 departing LGW suffered stall on nos 1 & 2 engines due xwind, just after V1. Managed to get airborne. The F/E was dumping fuel even as the a/c was still on the roll & before rotation. The a/c just cleared Russ Hill 2 miles to the W then disappeared from view, whereupon the controller hit the crash alarm. The altitude readout on RADAR was showing 002 for a while; a cheer apparently went up when it read 003. The a/c returned & made an overweight landing. The rumour that twigs were found in the undercarriage are unfounded as they had the gear up before they got to the hill.
So, yes, you CAN depart after V1 & before Vr with a 747 with 2 out on the same side.
Not correct
.... as the main wheels left the runway No. 4 engine surged
... see
www.fromtheflightdeck.com for the.
video. The video clearly shows that the engine never regained thrust.
The aircraft was allowed to pitch up 22 deg which is 11 degrees greater than recommended. There is some evidence that the No.1 engine surged temporarily so that thrust was fully recovered in 2-3 seconds.
Fuel dumping began shortly after the engine failure (in the air)
and continued for some 40 min.s until the required landing weight was achieved..
However there are instances where a B747 has taken off successfully with two engines out on one side
after reaching Vr, it all seems to depend on weight and performance for the day.