This was a British unrealised plan by the Combined Operations Headquarters to recapture the island of Alderney in the German-occupied Channel Islands (March/May 1942).
Schemed on the basis of an assault force of 2,150 men (standard infantry and commandos) supported by armour, the plan was dropped after a more realistic assessment decided that the retention of the islands so close to German-occupied France would be almost impossible. By this time many of the units involved had been assembled and some training had also been undertaken on the Isle of Wight.
The initial plan was to re-take and hold the island indefinitely, but a more realistic appreciation reduced this to one day, and the considerable reservations of RAF Bomber Command and RAF Fighter Command were among the reasons why the plan was later cancelled as unrealistic.
In the initial proposal of 16 April 1942, the object of taking Alderney by attack and then holding it were to provide a small craft base for cutting the German convoy route along the coast of France, the establishment of a radar station to extend Fighter Command coverage, the establishment of emergency landing strip, the creation of a diversion which might have led the Germans to withdraw air forces from other fronts (including bombers from Norway), the creation of a diversion which might have led the Germans to withdraw ground forces from other fronts, the creation of an opportunity to bring German air strength to battle under reasonably favourable circumstances, and the provision of a springboard for further combined operations.
The naval force required for this operation were listed as six escort destroyers, five infantry assault ships (with four support landing craft and 36 assault landing craft), eight motor gun boats, four shore-based assault landing craft, 18 tank landing craft, 30 personnel landing craft and four other craft. The military force was to comprise four infantry battalions, one parachute battalion, one commando reinforced by two troops of another commando, one squadron of tanks reinforced by one or two troops of another squadron, 13 Bren Gun Carriers, four bulldozers, one battery of light artillery, three batteries of light anti-aircraft artillery, one field company of engineers, one machine gun company, and a number of signals, medical and service corps detachments. The air force was to comprise bombers for 330 sorties, 40 transport aircraft to drop paratroopers, eight smoke-laying aircraft, one fighter wing for the protection to returning aircraft, fighter wings to cover shipping in the harbour, fighter wings to cover the withdrawal of the shipping on D+1, aircraft to make four intruder sorties against German airfields on the night of the assault , one AA suppression squadron, one close support fighter squadron with another on call, a fighter sweep to anticipate the first German reaction, offensive sweeps to met the air situation as it developed, and an RAF servicing commando.
After further deliberation on 5 May 1942 the air commander reduced the operation to a large scale raid, to take and hold the island for 24 hours, or may be longer if the situation and German reactions allowed. The parachute drop was abandoned. This scaling down of the undertaking would have called for a naval element comprising six escort destroyers, five infantry assault ships (with five support landing craft, 33 assault landing craft and two medium landing craft), eight motor gun boats, 17 tank landing craft, 30 vehicle landing craft and one hospital carrier); a ground force element comprising six troops (550 men) of the Special Service Brigade, 14 Churchill infantry tanks, 13 Bren Gun Carriers, four 3.7-in (94-mm) howitzers, one field company of engineers, one troop of four 40-mm Bofors anti-aircraft guns, one field ambulance, and support elements for a total of 3,00 men; and an air element comprising 200 to 250 medium and heavy bombers, 24 Bristol Blenheim light bombers with 500-lb (227-kg) HE and 250-lb (113-kg) smoke bombs, 14 Blenheim aircraft to lay smoke screens, 18 long-range coastal fighters, 24 squadrons of Supermarine Spitfire fighters, 12 intruder aircraft and 24 night fighters.
The 1st Guards Brigade was put on notice to move to the Isle of Wight for training, but in the end the 'Blazing' was abandoned in favour of 'Jubilee' against Dieppe.