Armstrong was born in Toronto, Ontario, the youngest son of Fred and Emily Armstrong, and was educated at Upper Canada College between 1909 and 1912. He joined the Royal Naval Air Service, being commissioned as a probationary flight sub-lieutenant, for temporary service, on 1 December 1915. After completing his basic flight training, he was granted the Royal Aero Club Aviator's Certificate No. 2675 on a Maurice Farman biplane at the Royal Naval Air Station, Chingford, on 3 April 1916. In June 1916 his probationary period came to an end.
Aerial service
Armstrong was first posted to No. 3 Wing RNAS, part of a joint Franco–British force formed to fly bombing raids on German industry. The British contingent was based at Luxeuil-les-Bains and flew a variety of aircraft, but principally the Sopwith 1½ Strutter, and flew its first mission on 30 July 1916. In January 1917 nine pilots from No. 3 Wing, of whom Armstrong was one, were selected to become the nucleus of the newly formed No. 3 Squadron. Armstrong joined No. 3, based at Dunkirk, in February 1917, to fly the Sopwith Pup single-seat fighter. He scored his first victory on 6 April 1917, in Sopwith Pup serial no. N6178. Using this same aircraft, on 12 April, he shared his second victory with fellow ace Edmund Pierce. In late April he was awarded the Croix de Guerre by France. His third win was shared with Pierce and Arthur Whealy on 2 May, when they set an Albatrosreconnaissance aircraft ablaze. A fourth victory, four days later, an Albatros D.III sent down out of control over Bourlon Wood, was shared with Kerby. Armstrong was promoted to flight lieutenant on 30 June, and on 7 July, a splashed German seaplane six miles north of Ostend was worth a win apiece for Armstrong, Joseph Stewart Temple Fall, James Alpheus Glen, and Leonard Henry Rochford, and Armstrong became an ace. He then switched to the Sopwith Camel. Thus mounted, he scored two single-handed wins on 16 September 1917. Armstrong was subsequently awarded the Distinguished Service Cross, which was gazetted on 27 November 1917. His citation read: On 31 December 1917 he was promoted to flight commander. He resumed his victories on 24 January 1918. He went on to score five times in March 1918; the last win, on 24 March, seems to have been a squadron affair, with Armstrong, Pierce, Whealy, Edwin Hayne, Frederick Britnell, and three other pilots all being credited with a victory for driving an Albatros D.V down out of control.
List of aerial victories
Death in action
Armstrong was shot down in flames south of Ervillers on 25 March 1918 while he was on Special Patrol, and was listed as "Missing believed killed". As one of the Commonwealth airmen killed the Western Front who have no known grave he is commemorated at the Arras Flying Services Memorial, and there is also a memorial plaque to him in the Church of the Redeemer, Toronto. He also appears on the Hawksdown Aerodrome Memorial in Walmer, Kent. He is also listed on the Commemorative Stand located on the site of Walmer Aerodrome which was unveiled by the Lord Warden of the Cinque Ports in August 2017.
