After the war Hubbard flew transport aircraft in the Middle East, where he was personal pilot to the Commander-in-Chief. Then, in January 1948, he started the one-year course at the ETPS. This was followed by three years at Farnborough testing and evaluating the RAF’s fighters, including the various marks of Meteor and Vampire jets.
In August 1950 Hubbard was walking across the airfield when he heard a humming, hissing sound. He reported: “I turned round and saw a strange object approaching. It looked like an edge-on view of a sports discus.” A month later he was with five other officers when they had a similar sighting, and the MoD’s chief scientific officer, Sir Henry Tizard, established a Flying Saucer Working Party to investigate.
Despite the calibre of the RAF witnesses, the working party summarily dismissed Hubbard’s sighting as an “optical illusion”. It also concluded that the five additional witnesses “saw some quite normal aircraft at extreme range and were led by the previous report to believe it to be something abnormal”. The report was classified as secret and did not come to light until 2001. When advised of the working party’s conclusion, Hubbard responded: “Absolute rubbish. My engineering experience convinced me it was not of this earth.”
Hubbard’s next appointment, in 1952, was flying Meteor day fighters with No 92 Squadron, based in Yorkshire, initially as the flight commander and then as squadron commander. He then progressed to the Day Fighter Development Squadron at West Raynham, where he and his fellow pilots developed tactics and assessed the new generation of fighters, including the Hunter and the Swift.
After his tour at Aero Flight, Hubbard attended the Indian Air Force Staff College before spending two years on an exchange appointment with the USAF. He served as Deputy Director of Fighter Operations at HQ Tactical Air Command, where his two years culminated in planning operations during the Cuban missile crisis.
In November 1962 he returned to ETPS as the chief test pilot instructor, an appointment that gave him the opportunity to fly many different British, American and European aircraft. In 1965 he decided to take early retirement. He was awarded an AFC in 1948 and a Bar in 1952.
In September 1965 he and his family left for California, where he worked for McDonnell Douglas Aircraft as director of special projects. In 1973 he moved to Virginia, where he established his own defence technology company .