My grandfather was a Lancaster bomb aimer/forward gunner and when I was a kid told me war stories. Two I remember are one time while dropping incendiary bombs one hit his bomber and he had to quickly poke it back out of the hole it made. Also a sentiment he expressed was that the forward gun was useless and detrimental to the planes flight characteristics.
So basically my questions are how often did bombers accidently hit each other and what was the general consensus about the effectiveness of the forward guns on the Lancaster/ bombers?
*edit I think it may have been his pilot/ Co-pilot that shoved the bomb back out of the plane.
Am I allowed to use Max Hastings' Bomber Command as a source?
RAF Bomber Command sent its aircraft in tight compact streams so as to swamp the Kammhuber Line and other defences.
The Luftwaffe night fighter defences were organised in the Himmelbett system which in had a single night fighter attached to a Freya radar and ground controller. So if Bomber Command sent their aircraft over in a stream, this meant that they would only be attacked by a single fighter in each Himmelbett cell.
Because the bombers were so close together, in streams separated by altitude, being hit by bombs from the stream above was a common problem, especially for the Short Stirling. The Stirling had a much lower ceiling than the other 4-engined RAF bombers, and therefore ended up in the lower streams underneath all the other bombers.
According to Len Deighton, crews of other RAF bombers were known to cheer when they were told that a raid included Stirlings, because this increased their own chances of survival.
Although not specifically for the Lancaster, Hell's Angles by Jay Stout and Masters of the air by Donald Miller mostly focus on the American B-17s but do touch on the British raids. The Germans loved to make head on passes at the B-17 because the early models had weak frontal armament, so comparatively the Lancaster was better defended head on with the twin guns in the turret mounting. So far as aircraft hitting each other, yes it did happen. Formation flying, especially at night and bad weather, did lead to a number of collisions. One of the big differences between the B-17 and the Avro Lancaster was that the Avro in some models had four machine guns in the tail vs. the two on the B-17 and the Avro had a much larger available bomb load, which is why they got used for dam busting operations.