Sabre dance (aerodynamics)

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The Sabre dance is the name given to pitch-up, a particularly dangerous behaviour of swept wings, which became apparent in the USAF during the development of the F-100 Super Sabre. When a swept wing starts to stall the outermost portions tend to stall first. Since these portions are behind the center of lift, the overall lift force moves forward, pitching the nose of the aircraft upwards. This leads to a higher angle of attack and causes more of the wing to stall, making the problem worse until the pilot loses control. This problem could easily have fatal results at low altitude, where there was insufficient time for the pilot to regain control or eject before hitting the ground: a large number of aircraft were lost to this phenomenon during landing, leaving the plane tumbling onto the runway, often in flames.

One of the most notorious incidents was the loss of F-100C-20-NA Super Sabre 54-1907 during an attempted emergency landing at Edwards AFB, California on January 10, 1956. By chance, this particular incident was recorded in detail on 16 mm film by cameras set up to cover an unrelated test. The pilot fought desperately to retain control as he rode the edge of the flight envelope, but his F-100 fell off on one wing, slammed sideways into the runway and exploded, killing him.

The brand new F-100C was flown by Lt. Barty R. Brooks, a native of Martha, Oklahoma, and a Texas A&M graduate, of the 1708th Ferrying Wing, Detachment 12, Kelly AFB, Texas, and was one of three being delivered from North American's Palmdale plant to George AFB, California, but the nose gear pivot pin worked loose, allowing the wheel to swivel at random, so he diverted to Edwards which had a longer runway.[1] Nose high, the fighter exceeded its flight envelope, and, too far into stall condition, lost directional control with fatal results. These scenes were inserted in the movie The Hunters, starring Robert Mitchum and Robert Wagner,and in the movie X-15 with actor Charles Bronson playing the unlucky pilot.[2] The incident was also commemorated in the fighter pilot song "Give Me Operations" (set to the tune of the California Gold Rush song "What Was Your Name in the States?"):[3]

"Don't give me a One-Double-Oh
To fight against friendly or foe
That old Sabre Dance made me
crap in my pants
Don't give me a One-Double-Oh."[1][4][5]

References[edit]

  1. ^ a b Deadly Sabre Dance
  2. ^ The Sabre Dance
  3. ^ Ives, Burl, "Burl Ives Song Book", Ballantine Books, Inc., New York, November 1953, page 240.
  4. ^ mudcat.org lyrics: WHAT WAS YOUR NAME IN THE STATES
  5. ^ The Unhymnal - Unofficial songbook of the Clemson University bands, edit circa 1967, Clemson University, Clemson, South Carolina.