He was credited with having shot down at least twelve aircraft Born in New York City to Canadian parents, Keefer joined the RCAF in late 1940.

He spent several months with the squadron and achieved a number of aerial victories before being assigned to instructing duties.

He returned to the United Kingdom in early 1943 and after a few months resumed operational flying with a posting to the RCAF's No.

His parents, Canadian citizens, subsequently relocated to Charlottetown on Prince Edward Island in Canada.

Once Keefer finished his schooling, he returned to the United States in 1939 to study engineering at Yale University.

He broke off his tertiary education after a year, enlisting in the Royal Canadian Air Force (RCAF) in October 1940.

[1] Keefer underwent flight training in Canada, gaining his wings in April 1941 and receiving a commission as a pilot officer.

Two months later, he was sent to the United Kingdom to join in the war effort there, serving with the Royal Air Force.

It was based in Egypt at Mariut and operated Hawker Hurricane fighters, providing aerial protection for Royal Navy shipping and bomber escorts.

[2][3] On 7 December, Keefer achieved his first aerial victories, destroying a Macchi C.200 fighter of the Regia Aeronautica (Italian Air Force), and damaging a second, to the south west of El Adem.

On 4 June, he was involved in the rescue of a South African pilot who had been shot down near Bir Hakeim, landing nearby to collect and fly him back to his airfield, both men squeezed into the cockpit of Keefer's Hurricane.

[6] On 12 June, while the squadron was on a shipping reconnaissance, Keefer damaged a Focke-Wulf Fw 190 fighter to the north east of Île de Batz.

126 Fighter Wing began operating from airstrips within the beachhead, using these as re-fuelling posts in between patrols before returning to their base in the United Kingdom at the end of the day.

The published citation read: This officer has completed many sorties since being awarded a Bar to the Distinguished Flying Cross and his record is outstanding.

The successes obtained reflect the greatest credit on the skill, gallantry and resolution of Wing Commander Keefer.

On 20 April he destroyed a Bf 109 at Wittstock and then, close to Pritzwalk, he shot down a Fw 190, his final aerial victory of the war.

[17] He was also recognised by the governments of France and Netherlands for his war service, being awarded the Croix de Guerre with a Star and Airman's Cross respectively.