[tcolvin]

"Operational Research Section Report Number 28, The Use of Mobile Control Posts for Air Support of the Army" included a Part II that was issued also as a Joint Report by ORS 21 Army Group and ORS 2nd TAF entitled "Note on the Accuracy of the MRCP".

Background; From Feb 8 to March 5, No 1 MRCP controlled 409 planes, medium and fighter bombers, in 9 raids which dropped 1,478 bombs (348 tons) on targets requested by the army. In the latter part of the period, the MRCP was at Materborn near Main HQ 2 Canadian Corps, close to Kleve and 37kms from the Wesel bridges. (By the way, Churchill, Brooke and Montgomery visited this HQ on the morning of March 4. Churchill was provided whisky in a tin mug of 'tea' by order of Simonds who got him volubly merry. Montgomery fumed).
All missions were flown in conditions when without radar they would have not been attempted.
Aircraft flew at 10,000 ft above light Flak, usually in 10/10th cloud.
On March 5;
a) 42 Mitchells loaded with 500 lb MC bombs (Medium Capacity, streamlined bombs with a charge to weight ratio of 40-50%) were targeted at the Wesel rail bridge and achieved a displacement of Mean Point of Impact (MPI) of 460 yards and 480 yards, checked from photographs and not ground checked.
b) 36 Mitchells with same bombs as above targeted the Wesel road bridge with a displacement MPI of 400 yards and 480 yards, also calculated from photographs.
Report conclusions;
- average MPI displacement of all nine raids was 300 yards
- this accuracy is comparable with those achieved by visual methods in level bombing
- this accuracy means that such targets can safely be engaged closer to our own troops than by any other existing radar means.
Source: 'Montgomery's Scientists', edited by Terry Copp

Tony