| H.P.54 Harrow | |
|---|---|
 Harrow of No. 115 Squadron | |
| General information | |
| Type | Heavy bomber |
| Manufacturer | Handley Page |
| Designer | |
| Primary users | Royal Air Force |
| Number built | 100 |
| History | |
| Manufactured | 1936–1937 |
| Introduction date | 1937 |
| First flight | 10 October 1936 |
| Retired | 1945 |
The Handley Page H.P.54 Harrow was a heavy bomber designed and produced by the British aircraft manufacturer Handley Page. It was operated by the Royal Air Force (RAF) and used during the Second World War, although not as a bomber.
The Harrow was developed during the 1930s as a derivative of the Handley Page H.P.51, an unsuccessful monoplane bomber-transport hybrid. It was a twin-engine, high-wing monoplane with a fixed undercarriage. In 1935, the Air Ministry wrote Specification B.29/35 around the Harrow proposal, seeking a 'stop-gap' heavy bomber to facilitate the expansion of the RAF's bomber squadrons. Handley Page updated the design with new features and along with structural changes to enable more rapid construction. Despite incorporating several modern features, including hydraulically-powered turrets, steam-based cabin heating, and variable-pitch propellers, the performance of the Harrow did not match that of contemporary bombers such as the Armstrong Whitworth Whitley.
On 14 August 1936, the Air Ministry ordered one hundred Harrows for the RAF. While the Fleet Air Arm also placed a separate order for one hundred Harrows, Handley Page did not have the capacity to produce these aircraft. On 13 January 1937, the first Harrow was delivered to No. 214 Squadron; by the end of that same year, all one hundred of the RAF-bound units had been delivered. By the end of 1939, the Harrow had been rapidly displaced as a frontline bomber, it was flown as a transport aircraft instead, which included its use as an air ambulance. It participated in several major actions, including an unorthodox defensive role for The Blitz in the winter of 1940–1941 and Operation Market Garden in September 1944. Limited numbers served through to the conclusion of the conflict, the RAF withdrew the Harrow in May 1945.