The estimate has appeared in many sources that this raid set back the V-2 experimental programme by at least two months and reduced the scale of the eventual rocket attack. The V-2 team had to hastily move their testing facilities elsewhere. The Master Bomber became a common feature of large-scale raids from this time onwards. The United States Army Air Forces operated a similar force within the Eighth Air Force for "blind-bombing" through overcast on daylight missions using H2X radar-equipped bombers, for which it also used the terms "Pathfinder", "PFF", and "master bomber". Rivalry in Bomber Command Although the AOCs of the Groups had been mixed in their enthusiasm for the Pathfinder Force, they generally supported it. AVM Roderic Carr (4 Group) was opposed to its creation but had identified Bennett (10 Squadron was in his group) as the sort of person suitable for the job and passed over a squadron of Halifax heavy bombers. AVM Coryton had been a greater opponent but supplied a squadron of the new Avro Lancasters. There was rivalry between 8 Group and 5 Group, driven by the rivalry between Bennett and the commander of 5 Group, Sir Ralph Cochrane. Through the CO of 617 Squadron Leonard Cheshire, Cochrane was an advocate of precision low-level marking and lobbied to be allowed to prove the theory and for 5 Group to attempt targets and techniques that 8 Group would not. Cheshire marked targets using the fast Mosquito bomber, then later a Mustang fighter bomber. 617 Squadron achieved high levels of accuracy using the Stabilizing Automatic Bomb Sight; with the necessary accuracy of only at the V weapon launch site at Abbeville. 5 Group also invented various techniques, such as the "5 Group corkscrew" to evade enemy fighters, and the "quick landing system". Light Night Striking Force The Light Night Striking Force (LNSF) was a development of the Pathfinder Force's use of the fast and long-ranged Mosquito bomber, which could carry a sizeable bomb load. Under 8 Group, the number of Mosquito squadrons was built up and used for harassing raids on Germany. To the two (Oboe-equipped) Mosquito squadrons already in the Pathfinder Force, 139 Squadron was added in June 1943, which Bennett intended to use for diversionary raids to draw the German night fighters away from the main force. In February 1944 a raid made entirely by Mosquitos was mounted against Düsseldorf. It was formed of