September 15, 1948 – The F-86A Sabre Breaks the World Speed Record

On this day in engineering history, an F-86A Sabre jet set a new world speed record of 670.97 mph. Built by North American Aviation, this Sabre was a high-altitude day fighter with a range of 1200 miles and combat ceiling of 49,000 ft.

The first Sabre prototype flew on October 1, 1947, just weeks before test pilot Chuck Yeager broke the sound barrier in his Bell X-1. Six months later, on April 26, 1948, this same prototype Sabre, the XP-86, broke Yeager's record. Subsequent F86 Sabres, each bearing a lettered designation, would set and break world speed records during the 1950s.

Yeager vs. Welch

According to military historian Joe Baugher, a prototype Sabre may have broken the sound barrier before Chuck Yeager's historic test flight in the fall of 1947. During early test flights, XP-86 pilot George "Wheaties" Welch reported "unusual fluctuations in his airspeed and altitude indicators during high speed dives." Whether these "fluctuations" prove that the XP-86 broke the speed of sound remains in dispute. At the time, North American Aviation "had no way of calibrating airspeed indicators into the transonic range," Baugher explains.

Unambiguous

The F-86A that re-wrote the record books on September 15, 1948 was less ambiguous in its accomplishments. As the U.S. Air Force's first swept-wing fighter, the Sabre featured a 4.78-aspect-ratio wing of 35-degree sweepback. This design was derived from captured German data about the advanced Messerschmitt fighter and complemented by a powerful J47-27 engine. Built by General Electric, this powerplant produced 6,000 pounds of thrust for the F-86F Sabre, a later version that followed Sabre redesigns as an all-weather interceptor (F-86D) and a fighter bomber (F-86H).

10:1

During the Korean War, three day-fighter versions (F-86A, F-86E, and F-86F) of the Sabre jet battled the Russian-built MiG-15. According to the National Museum of the U.S. Air Force, the Sabre shot down 792 MiGs while losing only 76 planes – a victory ratio of 10 to 1. More than 5,500 Sabre day fighters were built in the United States and Canada until 1956, when the F-100 Super Sabre made the F-86 Sabres obsolete.

Resources:

http://sectionf8.com/history.html

https://en.wikipedia.org/wiki/F-86_Sabre

https://www.globalsecurity.org/military/systems/aircraft/f-86.htm