Avro Lancaster Mk II B with air cooled Hercules engines, 514-British Squadron comes to land to English airfield of Deenethorpe.
The Mk II was the only version of the Lancaster not to be powered by Rolls Royce Merlin engines. Instead, it used Bristol Hercules radial air cooled engines. The aim was to provide an alternative source of Lancasters in case the supply of Merlin engines failed. British production was seen as vulnerable to German bombing, while there were worries that American production (by Packard) would be diverted or stopped if American entered the w
