The A- and B-flights departed Iceland for RAF Oban in Scotland on 23 January 1943. This involved a switch to the Short Sunderland flying boat. These were expensive aircraft which the Norwegian government-in-exile could not afford. The RAF therefore agreed to lend the aircraft to the squadron, while operating costs were still paid for by the Norwegians. The squadron was set up with six Mk II and six Mk III, the latter having somewhat longer range. There were technical challenges with the Bristol Pegasus engines, which were underpowered and often stopped mid-air. The situation was often aggravated when the feathering malfunctioned.