The first Harrow was delivered to No. 214 Squadron RAF on 13 January 1937, with all 100 delivered by the end of the year, with five bomber squadrons of the RAF being equipped with the Harrow. The Fleet Air Arm ordered 100 Harrows but Handley Page lacked the production capacity to supply them. Despite being fitted with cabin heating by steam boilers using exhaust heat, the Harrow gained a reputation of being a cold and draughty aircraft, owing to the turret design. As the delivery of more modern bombers increased, the Harrow was phased out as a frontline bomber by the end of 1939 but continued to be used as a transport. 271 Squadron was formed on 1 May 1940 with a mixture of Harrows, Bristol Bombays and impressed civil aircraft. While the other aircraft equipping 271 Squadron were replaced by Douglas Dakotas, it retained a flight of Harrows (sometimes nicknamed "Sparrows" due to their new nose fairings to give a more streamlined fuselage) as transports and ambulance aircraft until the end of the Second World War in Europe.