Originally Posted by
Wensleydale
Before WW2, the pilot was responsible for everything to do with the aircraft and the observer "observed". At the beginning of WW2, a directive from Bomber Command stated that each bomber had to carry two pilots and two WOps in case the primary was incapacitated. On 4 seat aircraft, such as the Hampden therefore, the observer role was carried out by a junior pilot who gained experience from the aircraft nose before being given his own crew. Indeed, breaches in flying discipline by pilots often led to a spell as observer for the unfortunate miscreant. One pilot at Waddington was peeved when he had to air test his Hampden rather than go to the outdoor swimming pool in Lincoln with the rest of his Squadron. He therefore treated the pool to a very low flypast which was unfortunate because the chap on the diving board who had to jump in to avoid the Hampden happened to be his Squadron Commander. The result was a month restricted to flying as observer. Shortly after, the pilot (Dave Romans) was on a raid when he felt the aircraft begin to reach the stall and dive. He made his way through the tunnel under the pilot to find his pilot slumped unconscious over the controls. Unable to move him, Romans collapsed the back of the pilots' seat and sat on the prone body of the pilot to bring the Hampden back under control. The wireless operator eventually noticed what was happening and pulled the pilot from under Romans allowing him to safely bring the aircraft back to Waddington. Unfortunately, the pilot later died - he had been hit by a piece of flak shrapnel that had punctured his skull, just behind his ear. Dave Romans was awarded an immediate DFC - and got his captaincy back. The two pilot rule was later rescinded as there were insufficient pilots being trained to cover losses of two per aircraft.
I think before the war all multi engined bombers ( aside of the Hampden) carried 2 pilots. The change back to single pilots was more to do with the expansion of the force and the introduction of the 4 engined heavies/ flight engineers being introduced.