Monday, 15 July 2013

Kulbit and Pugachev's Cobra

Kulbit

File:Su-37 Kulbit.png


The "Kulbit" (also known as "Frolov chakra", named after Yevgeni Frolov, Russian test pilot) is an aerial maneuver developed by Russian pilots, in which the aircraft performs an extremely tight loop, often not much wider than the length of the aircraft itself. It is an example of post-stall maneuvering, a type of supermaneuverability. Like most post-stall maneuvers, it demonstrates pitch control outside of the normal flight envelope wherein pitch control is made possible by having aerodynamic flow over the aircraft's elevators or stabilators.
The Kulbit drastically decreases the aircraft's speed and could theoretically be used to cause a pursuing aircraft to overshoot its target. The maneuver is closely related to the famous "Pugachev's Cobra" maneuver, but the Kulbit completes the loop that the Cobra almost immediately cuts off.

Aircraft known to be able to execute the "Kulbit"

The following aircraft are currently known to be able to execute the "Kulbit"

  • MiG-29OVT
  • Sukhoi Su-35
  • Sukhoi Su-37
  • Sukhoi Su-30
  • F22 Raptor
  • Su-47 Berkut
  • PAK-FA

Pugachev's Cobra


File:Su-27 Cobra 2b.pngIn aerobaticsPugachev's Cobra (or Pugachev Cobra) is a dramatic and demanding manoeuvre in which an airplane flying at a moderate speed suddenly raises the nose momentarily to the vertical position and slightly beyond, before dropping it back to normal flight. It uses potent engine thrust to maintain approximately constant altitude through the entire move. The manoeuvre supposedly has some use in close range combat, and is an impressive trick to demonstrate aircraft's pitch control authority, high angle of attack (AOA) stability and engine-versus-inlet compatibility, as well as the pilot's skill. The manoeuvre is named after the Soviet test pilot Viktor Pugachev, who first performed the manoeuvre publicly in 1989 at the Paris Le Bourget air show.Initially the Cobra was performed by Sukhoi's test pilot Igor Volk while testing the new Sukhoi Su-27fighter.

While Pugachev's Cobra can be executed using only standard aerodynamic controls, it could be achieved more easily with modern thrust vectoring. In the latter case it would be an example of supermaneuverability, specifically poststall maneuvering. The Herbst maneuvering and the helicopter manoeuvre are other examples of the recent growing use of vectored thrust in 4.5 and 5th generation aircraft, manned as well as unmanned

This maneuver could theoretically be useful when a combatant is being pursued closely by an opponent at a somewhat higher altitude. By executing the cobra, a pursued aircraft may suddenly slow itself to the point that the pursuer may overshoot it, allowing the previously pursued aircraft to complete the Cobra behind the other. This may give the now-pursuing aircraft an opportunity for firing its weapons, particularly if a proper pointing aspect (facing toward the former pursuer) can be maintained. Maintenance of the proper aspect can be facilitated when the aircraft employs thrust vectoring and/or canard control surfaces. The disadvantage of performing this maneuver is that it leaves the airplane in a low speed/low energy state, which can leave it vulnerable to attack from opposing aircraft.


Examples of aircraft capable of the maneuver

  • Sukhoi Su-27 and variants (Su-30/Su-30MKI/Su-30MKM, Su-33, Su-35, Su-37and Shenyang J-11)
  • Mikoyan MiG-29 and Mikoyan MiG-35
  • Lockheed Martin F-22 Raptor
  • F-15 STOL/MTD
  • PAK-FA
  • Su-47 Berkut


No comments:

Post a Comment