 1653 Heavy Conversion Unit RAF with Consolidated Liberators.The original runways were approximately 1,600 yards and 1,100 yards in length.However, these were unsuitable for the operation of heavy, four-engined bombers and the field was upgraded to Class A airfield standards, including the lengthening of the runways to the required 2,000 yards for the main and 1,400 yards for each of the others, started in late 1942.