In 1957 he changed over to the air force and was trained as a pilot at Landsberg am Lech and Fürstenfeldbruck on the T-6 Texan, the F-84 Thunderjet and the Lockheed T-33.

[1] His brother Bernd also served in the air force and was one of four Lockheed F-104 Starfighter pilots killed on 16 June 1962.

In 1972–74 he served as a department director at the Luftflottenkommando in Cologne and in 1977 he became the German Military attaché in Madrid and in 1979, by then a Brigadegeneral, in London.

1989–91 Kuebart served as the Deputy Commander and Chief of Staff of Allied Air Forces Central Europe.

[1] After his retirement, from 29 September 2000 to 6 October 2006, he served as president of the Gemeinschaft der Jagdflieger, a German veterans organization.