One of the issues that is cropping up in researching Operation CRUSADER through contemporary documents is the question of whether or not air attack was successful in causing damage on the ground. There is no doubt that the respective air forces thought it was, and claimed so in their own documents and/or post-war histories (see e.g. the entry on air power in North Africa and my comment on the RAF history on the Thoughts on Military History blog). Nevertheless, it is questionable whether these rather biased judges were right all the time.
The only way me and Michele, whom I am collaborating with on the air aspect, can see to get at this is to try to link ground attack missions to entries in war diaries or first person accounts (where the former are not available) on their effect. This is painstaking work, and I am not sure we’ll get it done. Based on an initial review of the issue, and some early looks into the data, it appears that the research hypothesis would be ‘ground attack missions on mobile targets were rarely successful during Operation CRUSADER’, with success being defined as the mission causing significant damage levels or disorganisation in proportion to the air effort expended. So you would normally expect an attack by 35 Ju 87 Stukas to lead to more damage than a strafing raid by two Fiat CR.42.
It’ll be interesting for us to see what we can come with in terms of data, and I am sure there’ll be some animated debate around it too, since it will challenge some widely held preconceptions.
Empire Notes from the receiving end
The information below is from Intel Summary No. 1 distributed to 15 Light Anti-Aircraft (LAA) Regiment R.A. in January 1942. It was based on the experience of 1st LAA Rgt. R.A. gained in support of 7 Support Group of 7 Armoured Division during Operation CRUSADER.
- Dive bombing (Stukas) on an average does practically no damage. Every effort should be made to educate gun detachments to this fact. They soon realize it after experience in action, but are apt to overestimate the potential of dive bombing before they have gained experience. Bombing of any sort can, in no way, be compared with shell fire from Field Guns and Tanks. Even concentrated fire of this nature causes remarkably small amount of damage, and this fact too should be given to gun detachments. Gun detachments which have experienced this nature of fire are completely derisive of bombing attacks.
The text below is from the same intelligence summary, but based on the experience of 57 LAA Rgt. R.A., which served under 4 Indian Division during CRUSADER.
During the whole of this period  the Regt. was actively engaged in its more natural pursuit of aerial targets and had duels with no less than 780 aircraft in 187 engagements.
The heaviest raids were during the eight days 7 to 14 December when successive Stuka attacks were delivered on all divisional areas. The attacks were delivered mainly on MT concentrations and Divisional HQ was a particular objective of the Ju 87.
One of the most notable features of these duels was the extreme respect with which the bomber treated “flak”, his approach being at greater heights and his dive shallower on each successive occasion. There can be no doubt that the Lt.AA completely spoilt his aim and helped to maintain the morale of the ground troops. The majority of this fire was outside normal Bofors range but it served its purpose.
Eighteen enemy aircraft were destroyed by the Regt. during the period but unfortunately no Me 109F was placed in the bag as these fleet “birds” gave little opportunity for practice.
British troops inspect a Junkers Ju 87 Stuka which made an emergency landing in the desert, December 1941. Courtesy of the IWM Photo Collection. 
 The report was very kindly looked up and made available by Drew, who also provides this service to others interested in National Archives files, for what I think is a very reasonable fee. You can find out more about this and contact Drew at this link.
 While somewhat confusingly written, it appears clear to me that on the hierarchy of threats the dive bomber ranks last, while the others (field artillery and tanks) are also to be discounted. The loss figures, when looking into particular engagements also contained in the report, seem to bear that out.
 4 to 27 December 1941
 During this period the Axis air forces still occupied airfields at Tmimi, Martuba, and Gazala, just 50 or so miles or less from the frontline, enabling them to send rapid raids multiple times a day to keep the advancing Commonwealth forces in check, to help cover the retreat of the Axis ground forces from the siege of Tobruk. For example, on 8 December Fliegerfuehrer Afrika managed to get 144 missions into the air, not counting Italian missions.
 Motor Transport
 A ratio of 2.3% of planes ‘duelled’, or roughly one plane shot down in 10 engagements.
 This appears to be T6+AN of 5./StG2. You can see a colour drawing of the plane at this link.