I have been reading Niall Corduroys book on the Whirlwind and was surprised to read that the RAF were genuinely concerned that if it was perceived that they were not adequately supporting the Army then, as had occurred with the RN FAA, the squadrons intended to support that service (the Army Cooperation Squadrons) would be parred off the RAF and form the nucleus of a new Army Air Corps or Army Air Service.
One of the reasons behind the small numbers in which the Whirlwind was built was that it had actually been cancelled, after the initial production orders had been placed, because the RAF and Air Ministry placed a very high priority (much higher than the Whirlwind) on producing the Westland Lysander. The reason the Lysander was so important is the RAF were obligated to provide sufficient Arm Cooperation Squadrons to equip the BEF and the apparently very real fear was if the RAF failed to adequately support the army, then forces sufficient to do so would be seconded from the RAF to form a new Army aviation service, in much the same manner as occurred with the FAA.
Dead easy whiff, this happened and the RAFs Army Cooperation Squadrons became the Army Air Corps. Reading on the Lysander it appears the type was what RAF pilots thought was needed for the job, not what the Army needed, let alone wanted. Just look at the Wirraways and Boomerangs the RAAF operated in the role to imagine AAC Henleys, Hurricanes, Tomahawks and Kittyhawks, perhaps even Taurus or Hercules powered variants of the Hawkers. The AAC serves with distinction through the war and after.