When the British learnt from the Norwegian Resistance that the Nazi appointed leader Quisling was holding a rally in Oslo it was decided to disrupt events with a low level raid. The new Mosquito aircraft was already demonstrating its capabilities as a low level precision bomber and was the obvious choice for the raid. It was to be the longest distance raid yet undertaken by the aircraft.
Squadron Leader George Parry of No.105 Squadron led the raid for the 1,100 mile round trip from RAF Leuchars in Scotland out across the North Sea:
We refuelled and bombed-up with four eleven-second delayed-action 500-lb bombs and set off at low-level, fifty feet all the way, to Norway. It was like flying down a long, straight road and we were using dead reckoning throughout. We went through the Skaggerak, made landfall at the southern end of Oslo Fjord and flew up the eastern side.
We flew up to a police radio station perched on a hill and I was told later I hit the flexible forty-five feet radio antenna, although it didn’t do any damage to my Mosquito.
We had been briefed that there would be 10/10th cloud at 2,000 feet over Oslo, but it was a lovely day with blue sky. We had also been told there were no fighters to worry about, but the Germans had brought a squadron of Fw190s south from Stavanger for a flypast during the parade. They had landed at Fornebu and had only been on the ground a short time when we arrived at 3 p.m. over the centre of Oslo.
A lookout at the southern end of Oslo Fjord reported us and they were scrambled. Two Fw190s got into the action. Fortunately, the rest did not get off in time.
Red tracer was going past me. Some of the Fw190’s shells hit the Royal Palace, although we were blamed for it at the time. I thought it was ground fire during our bomb run and didn’t realize he was after me until my No. 2 and No. 3 overtook me. I was concentrating on ‘buzzing’ the parade and taking a line south-west over the centre of Oslo for the bomb run.
We were travelling at 280-300 mph when I dropped my bombs. The speed the bombs were going meant they more or less followed us. They didn’t drop but a few feet. Then they slowed down and hit. It was only after I had dropped my bombs that my navigator noticed a fighter was behind us. I opened up rapidly and shook him off by flying up the valleys at low-level.
Parry got away but one other Mosquito was shot down. See Martin Bowman: The Men Who Flew the Mosquito
Photographic evidence is now confirmed by reliable ground sources. The main damage to the Gestapo Headquarters was in the rear of the building; the delayed-action bombs, which must necessarily be used in such low-flying attacks, passed clean through the Gestapo building and exploded next door.
An observer regretfully remarks that if the bomb had been only three metres lower it would have hit the centre of the front facade. He adds : ” German airmen and flak officers are impressed by the precision bombing, which was fantastically cleverly carried out; there are not so many German flags on the houses any longer.”.
From the report on Bomber Command Operations as submitted to the War Cabinet see TNA CAB 66/30/44. What the report does not mention is the number of Norwegian civilians killed, that the Norwegian Government in Exile, which had not been consulted about the raid, made representations about.
The exploits of the Mosquito crews of 105 Squadron were to become the basis, rather loosely, of the fictional 633 Squadron.