The brief was to shut down the right hand Derwent.
The good old Meatbox. Killed dozens of pilots practising single engined failure with one engine shut down; real engine were failures practically unknown. Endurance, as opposed to range; ie. being stuck above cloud at the end of the QGH line, was markedly improved by slowing down and shutting down an engine. The choice was simple: the generator, radios etc, was on the port engine, and the hydraulic pump on the starboard.
IIRC one had to get 270 knots at the last part the of the QGH to ensure that the engine was windmilling fast enough to relight otherwise there was a lot of pumping.