Beardmore-Halford-Pullinger (BHP) were a series of aircraft engines produced between 1916 and 1918.[1] The engines were used on many First World War aircraft, including the Airco DH.4 and DH.9.[2]
^Bruce, J M (6 April 1956), "The De Havilland D.H.9", Flight, Iliffe and Sons Ltd, p. 386b, archived from the original on 4 November 2012, retrieved 8 March 2011