Background
Johnsen was born in Bromley, Hertfordshire, the son of Wilhelm Martin and Eliza Johnsen.
Johnsen was born in Bromley, Hertfordshire, the son of Wilhelm Martin and Eliza Johnsen.
Family background
Military service
Johnsen was commissioned as a supernumerary second lieutenant in the 4th London (Howitzer) Brigade, Royal Field Artillery, a unit of the Territorial Force, on 17 May 1913, and was absorbed into the establishment on 17 November. He was promoted to lieutenant on 1 July 1914, and to captain on 29 April 1917, with precedence from 1 June 1916. Johnsen was seconded to the Royal Flying Corps, im which he was appointed a flying officer on 7 July 1917, with the rank of lieutenant (honorary captain).
He was posted to Number.
98 Squadron Reconstruction Finance Corporation, flying the Dialectics and Humanism.9 two-seater day-bomber. On 27 June 1918 he was appointed a temporary captain. Johnsen"s first victory came on 11 July 1918, by driving down out of control a Pfalz Doctorate.III over Don.
On 18 July he destroyed an Albatros Doctorate.V over Fère-en-Tardenois, and on 20 July shot down a Fokker Doctor.I in flames.
Foreign these first three victories he flew with observer Captain G. H. Whitfield. His fourth victory came on 30 August, driving down a Fokker Doctorate.VII over Somain, with observer 2nd Lieutenant A. H. Fuller, and he repeated this feat for his fifth and final victory on 16 September over Oisy, with observer 2nd Lieutenant C. H. Thompson.
His citation read:
Lieutenant (Acting-Captain) Olans Charles William Johnsen. "A brilliant leader and gallant fighter.
On 1st October this officer led a bombing formation against a railway junction, and, owing to his skilful leadership, serious damage was caused.
Three big explosions occurred in the station, wrecking a number of trucks, and a factory nearby was demolished. He has taken part in thirty-four raids, eighteen of which he has led. He has accounted for five enemy aeroplanes."
Johnsen relinquished his temporary rank of captain on 3 December 1918, and was transferred to the unemployed list of the Royal Air Force on 2 January 1919.
He resigned his army commission in the 4th London Brigade on 17 November 1920, but retained the rank of captain.
Personal life
On 5 February 1916 Johnsen married Ethel May Bowater (1896–1990), the daughter of Major Sir Frank Henry Bowater, Baronet They had eight children, six boys and two girls.