At the outbreak of World War I, Whitehouse came to England and enlisted as a Private with the Northamptonshire Yeomanry # 1784. He then transferred to the Royal Flying Corps # 78563. He was with the Northamptonshire Yeomanry again # 145871, then transferred to the Royal Air Force # 401090 

Service

He was a 1st Class Air mechanic and Observer with the No. 22 Squadron RAF. On 13 April 1917 Whitehouse and his pilot Bush were brought down by anti-aircraft fire; Whitehouse believed afterward that the Red Baron mistakenly listed Whitehouse/Bush among the Barons's "credits"-although this was not so. For taking part in shooting down German aircraft and airplane raiding missions, he was awarded the Military Medal with the RFC in November 1917. During the last part of World War I he was undergoing training in England as a pilot in Sopwith Camels. As of 28 September 1919 he was a 2nd lieutenant transferred to the Unemployed List. A notation on his Medal card noted he was awarded the British War Medal and British Victory Medal.

Contrary to reports that he brought down 16 enemy aircraft and 6 balloons, Whitehouse was never an ace, although he took part in the shooting down of four enemy aircraft:

12 August 1917 – an Albatross DV (burned), with pilot James Bush (RFC officer) M.C. {1/3 credit share in shootdown with two other pilots/observers}

12 August 1917 – an Albatross DV (out of control), with pilot James Bush (RFC officer) M.C. {1/2 credit in shootdown with another pilot/observer}

2 October 1917 – a "Two seater" (destroyed), with pilot James Bush (RFC officer) M.C.

10 October 1917 – a Albatross DV (destroyed over Moorslede, Belgium), with pilot William Meggitt, M.C.