[Cross-posted at The Aerodrome]
One of the advantages of being a researcher is the little gems of information that crop up from time to time in the course of examining new files. Having recently completed my MPhil I was pleased to come across to extra pieces of information in the course of my PhD research that supported the general conclusion I had reached with regards to the performance of the RAF over Dieppe. My general argument had been that the RAF had performed well in the course of the operation because Combined Operations doctrine had argued that the key role for air power was to fight and maintain air superiority over the attack force. This was its primary role before role such as aerial interdiction and direct air support could be affected in the battle area. Therefore, the key lessons learnt at the Dieppe for the RAF was the reinforcement of this idea and it is obvious that in subsequent Combined Operations the desire to attain air superiority was of paramount importance to the planners involved. This is not to say that Dieppe holds a central place in this source of information but that given the plurality of experience in 1942 this was the general conclusion reached.
The first source I came across was of even more use because it is a German source and was found in the papers of Marshal of the Royal Air Force Sir John Slessor. The file in question is entitled ‘The Effect of Air Power’ and was compiled by the Air Historical Branch based upon captured documents. The following extract from an 8th Abteilung Staff Study written in 1944 states that:
…The large-scale coastal landing operations which have taken place in the present war would not have been practicable without the co-operation of the air force…During the landings at Dieppe on August 19th 1942, support by the Air Force and consequent air supremacy, was necessary to equalise the position in view of the numerical inferiority of the ground troops landed and the weakness of the naval forces. Air power was also essential to protect the very vulnerable Allied transport shipping…
…As a result of the experience gained during the Dieppe operations as to the necessity of air supremacy, the Allies made certain of such supremacy in all subsequent landing operations…
It is interesting that the Germans use the term air supremacy for the air actions over Dieppe. I would characterise the RAF as gaining a degree of air parity i.e. enough to stop the Germans seriously interfering with the operations on the ground. At most we might consider the RAF having a degree of local air superiority though the loss of HMS Berkeley might bring this into question. Also it is interesting that the Germans also draw a more direct line from Dieppe to subsequent operations than I do. I find hard to ignore the lessons learnt in late 1942 and 1943 in the Mediterranean. However, this study, written in 1944, does not mention this.
I’ll post the other source later…
 Slessor’s paper are to be found in AIR 75 at the National Archives, Kew
 TNA, AIR 75/147, The Effect of Air Power
 TNA, AIR 75/147, The Effect of Air Power, p. 9