He was awarded the Military Cross (MC)[7] and Croix de Guerre avec Etoile en Bronze.

Working with a team of approximately fifty men he assembled enemy aircraft for (mostly static) display in Canada.

It included machine-shops, schools, garages, offices, quarters and messes, a central heating plant, paved roads, a swimming pool, golf course, and tennis courts.

These were, Johnson reported, 'lifted from the cars by means of a differential chain tackle, lowered onto a sleigh and drawn into a hangar by horses.

The spring thaw slowed unpacking until the men, who had to open up quarters and kitchens between shipments, rigged a wheeled, team-drawn trailer to replace the sleighs.

All had been damaged in transit and needed careful attention before they could be flown, but Johnson had the first, an Avro 504, fitted with Curtiss snow skids and test-flew it himself early in March.

Johnson tested each of the other machines as it was assembled, including four Airco DH.9As which were then shipped west for the first trans-Canada flight later that year.

By obtaining the sympathetic ear of the Chief of General Staff, consideration was given to the early provision of a mechanical peeler.

[24] He said of his interwar service it "was attempting to make bricks without straw", referring to the meager government appropriations and constant lack of equipment.

[26] During this period he was an early and enthusiastic supporter of the creation of the Royal Canadian Air Force Women's Division, although the idea did not become operational until July 1940.

In 1941, he was instrumental in framing and negotiating the agreement with the RAF that led to the creation of Canadian Air Groups (as opposed to just squadrons), allowing RCAF officers overseas staff command experience.

Stark, Chief of (US) Naval Operations in Washington, wrote to the Canadian Chief of Air Staff inviting him "to place such air forces as are assigned to perform ocean escort duty under the command, for this purpose only, of the Commander-in-Chief, U.S. Atlantic Fleet, this action to be taken under the authority and subject to the limitations contained in ABC-22...".

The Canadian Cabinet War Committee felt that since the navy was obliged to accept American command for oceanic convoy work the RCAF ought to do so as well.

Johnson, therefore argued that since the RCAF now operated very successfully in co-operation with, rather than under the control of, the RN and RCN there was no need to adopt different relationships with the USN.”[31] He was promoted to Acting Air Marshal while deputized for the Chief of the Air Staff during the Ottawa Conference held in May and June 1942 where he was in charge of the arrangements and the planning of material for discussion.

After taking command from AVM Cuffe, Johnson restructured relationships with the RCN and American forces, integrated new technology into the command (VLR Liberators, acoustic sonobuoys, homing torpedoes, enigma intercepts, radio direction finding sets, improved radars) to decisive effect.

Writing shortly after the war ended, Admiral Karl Dônitz noted that it was the "enemy air force" that was "the greatest problem for the U-boat command.

"[52]He was awarded the Companion of the Bath (Military),[53] the US Legion of Merit (Commander) and the French Légion d'honneur (Commandeur) as a result of his World War II service.

[55] His CB citation read in part:[56][57] Hugh Halliday, the noted RCAF historian, quoted Johnson as saying “It should be clearly understood that Commanding Officers who recommend recognition of the work of their subordinates are much more highly thought of by superior formations than those who do not.”[58] Johnson married Jean Eleanor McKay (1894–1968) in 1924, and they had two children, Jean Margaret (1930–1995) and Doreen Eleanor (1933-2008).

He was always in attendance at the annual Remembrance Day Dawn Patrol breakfast held by the Air Force Officers' Association of Vancouver.