Generally aircraft were ordered because they were needed, the problem was that what the various services thought they needed was not what was really required. At a higher, even doctrinal level many questions (who would protect the Navy's ships? How could an independent air arm support the Army?, even more fundamentally, what was an independent air arm for? Simply waging a srtategic campaign?) were not properly resolved.
Cheers
Steve
Well, very few air forces bought planes they
thought they didn't need. There was almost always
some reason behind the purchase.
Wither the reasons were sound is another question. And sound
only in hindsight or were there competing theories/reasons that argued against the purchase or for a different purchase?
Another complication was the passage of time. And politics. From the formulation of theory to formal requirement being issued (invitation for companies to submit designs) could take months (if not over a year). Time for designs to be submitted, evaluated and winning prototypes ordered and built. Time for final selection to be made and material ordered, factory tooled up and production to commence. Time for production planes to enter service in numbers.
Politics start to come into it in the numbers desired. Large expansions in numbers of squadrons call for
some sort of aircraft in the immediate future even if not what was really wanted. Theories/doctrine may have changed but putting off purchases delays the expansion (or leaves you with really obsolete planes should war start early). Changing doctrine too fast and canceling large programs in mid-stream can wind up with the politicians trying to micro-manage the purchasing programs because obviously the services involved couldn't be trusted with the tax payers money or they wouldn't be wasting it by shifting back and forth on doctrine. Nobody wanted to admit that program XXX was turkey or that program YYY wasn't what was wanted anymore. They just wanted to order program ZZZ while quietly letting Program XXX or YYY run out to the end (or at least the initial contracts).
What is puzzling is that so much experience from WW I seems to have been forgotten. Or deliberately ignored. Tactical bombing raids in WW I often had escorting fighters yet in France such escorts were almost totally lacking. In some cases they were assigned but failed to meetup for one reason or another (lack of training/co-ordination), In too many cases they may never have been assigned in the first place. Night fighting needed some re-learning even without radar. Night bombing had progressed almost zero in 20 years, air borne anti-sub warfare had gone backwards.
In some cases the British were buying
intermediate or interim aircraft to build up numbers and got caught before the desired replacements came into service.
I have very mixed feelings or thoughts about the Fairey Battle. Designed as a strategic bomber to get around a possible treaty clause it went into service in large numbers, in part because it was cheap, to build up the numbers of bombing squadrons. These new squadrons would, in time, be equipped with
real bombers. Unfortunately the Battle had to go into combat in role it was not designed for and without fighter escort. The Battle did fulfill a secondary roll as trainer for aircrew, ground crew and even a trainer for factory workers/factory planning. Many Arm Chair Air Marshals want to plan to cancel the Battle and get XXX number of better combat planes instead. While the exact number is subject to discussion very few of these ACAMs ( Arm Chair Air Marshals) want to talk about what would be needed to replace the Battle in the training role or the effect of poorer trained crews going into combat.
The Battle also seems to illustrate the divide between the
real role of the RAF and what was actually needed. Army support would be provided by whatever semi-obsolete aircraft the RAF could scrounge up to supplement the state of the art Lysander, while the RAF went on with it's true mission of bombing the enemy homeland into submission.