michaelharadon wrote:
Why just one pilot?
Or, one might ask of the USAAF, why two pilots?
Twice as much cost (training, billeting) for nothing like twice as much value!
I've never read a definitive answer. However the sea may be a factor.
RFC/RAF bombers of the Great War (end) were dual control types (Handley Page O/400, O/1500 Vickers Vimy etc) but some of that may have been to ensure sufficient muscle to manoeuvre. The second pilot often doubled up as nose gunner bomb aimer etc.
In the inter war era, there was a drift towards single pilot heavies, still offering a second set of controls (Handley Page Heyford) when required. Big maritime aircraft of the era, such as the Supermarine Southampton had a permanent two-pilot set up. As did the Stranraer and later the Short Sunderland.
Meanwhile the RAF's mediums were all single pilot operation (Blenheim, Hampden) while the same size
maritime reconnaissance types Avro Anson and (US designed, British spec) Lockheed Hudson had two pilot setup, although the second dickie was expected to fulfil other roles.
The concept of a flight engineer (even many other aircrew trades) as permanent jobs rather than second roles undertaken by groundcrew or pilots was not really known - arguably the RAF had become a "pilot's trade-union" driven air force.
The RAF's heavies weren't as heavy as they later became - the Manchester developed into the Lanc for instance, and I suspect the 'need' for a second pilot to relieve fatigue over a long raid wasn't really understood / expected.
Meanwhile it's often forgotten that at the design stage the B-17 and B-24 were strategic bombers with a maritime role expected - either long over-water or anti-fleet actions being required, so their was an expectation that two pilots were going to be required. Had the RAF specified a long-range maritime bomber, that might've had two pilots too; as the Sunderland etc, did.
In short, the USAAF came 'down' from long range strategic bombing ideas with two pilots, the RAF 'built up' from a pan-European bombing (but no maritime element) with one pilot - and had to add a flight engineer. They ended up flying similar raids on similar targets but starting from very different plans.
Very general with some debatable points, but some stuff to consider perhaps.