“The original Learjet could outclimb a fighter jet.”
Verdict: A true-in-1964 boast that became a myth by repetition. The Learjet 23 climbed at nearly 7,000 ft/min and could reach 40,000 ft in about seven minutes — genuinely quicker than several 1950s fighters, including the F-86 Sabre that Bill Lear's publicity liked to mention. Against a contemporary F-4 Phantom it was hopeless, and against anything since it isn't a contest. The story survives because the Learjet was built from a fighter design and behaved like one.
The Learjet 23 first flew in October 1963: two GE CJ610 turbojets, a thin high-speed wing borrowed from a Swiss fighter project, and almost no concessions to comfort. It was fast (Mach 0.82), unforgiving, and climbed like nothing the civil market had seen. Time-to-climb records were set in it, and pilots enjoyed telling air-traffic controllers they could take any altitude.
The fighter comparison is usually the North American F-86 Sabre, a 1949 design with an initial climb rate of about 9,000 ft/min at sea level but far poorer performance up high. Depending on altitude, load and which variant you pick, the Learjet could plausibly beat it to 40,000 ft. Sinatra's aircraft, in particular, was said to have out-climbed one in a friendly race — a claim that exists only in memoir.
Against the F-4 Phantom that entered service the same era (initial climb over 40,000 ft/min), the Learjet was a spectator. So the legend is best understood as 'outclimbed some fighters of the previous decade', which was still a remarkable thing for an executive aircraft to do — and a sign of how much the early Learjet asked of its pilots. Its accident record in the first decade was not good.
Sources: geaerospace.com · en.wikipedia.org
Aircraft in this story
