Cobra maneuver

In aerobatics, the cobra maneuver (or just the cobra), also called dynamic deceleration,[1] among other names (see § Etymology), is a dramatic and demanding maneuver in which an airplane flying at a moderate speed abruptly raises its nose momentarily to a vertical and slightly past vertical attitude, causing an extremely high angle of attack and making the plane into a full-body air brake, momentarily stalling the plane, before dropping back to normal position, during which the aircraft does not change effective altitude.

The maneuver relies on the ability of the plane to be able to quickly change angle of attack (alpha) without overloading the airframe,[2] and sufficient engine thrust to maintain nearly constant altitude through the entire move,[3] but also post-stall stability and aerodynamics that allows for the recovery to level flight.

The maneuver demands accurate pitch control, alpha stability and engine-versus-inlet compatibility for the aircraft, as well as a high skill level on the part of the pilot.

In the case of the Su-27, to execute the maneuver the pilot initially disengages the angle of attack limiter of the plane, normally set at 26°.

When the elevator is centered, the drag at the rear of the plane causes a torque that makes the aircraft pitch forward.

This may allow the now-pursuing aircraft an opportunity for firing its weapons, particularly if a proper pointing aspect (facing toward the former pursuer) can be maintained.

Due to the speed loss when performing a cobra, maintaining weapons on target may require the use of thrust vectoring or canard control surfaces.

While the cobra maneuver may appear to be useful to force a pursuer to overshoot, the tactic would almost never be employed in any active threat scenario for a variety of reasons.

If the closure rate is too high, the defender can change direction rapidly, which denies the attacker a shot opportunity, and thereby decreases the probability of kill.

Super stall plagued the early years of Saab 35 service, causing several deaths, which led the Swedish air staff to implement extra training on how to counteract and recover from them.

[14] The Swedish pilots soon considered how to use this move in combat to get a pursuing aircraft to overshoot, putting it in a perfect position for a riposte, and it was not long until it was proven viable during mock dogfights.

[2] Sweden effectively shared borders with the Soviet Union over the Baltic Sea, so both sides regularly flew into the international space between the two.

Due to the secrecy of the Cold War era and other factors, the Swedish cobra was largely unknown to the world until some former Saab 35 and 37 pilots wrote about it years later in books[2][12] and articles,[8][15] long after the Soviets had been credited with its discovery.

All of the unit commanders had been selected based on their political associations and loyalty to superiors, instead of knowledge of air combat.

The new commanders were over-reliant on advice from about 30 Soviet advisors assigned to the Syrian Air Force to help with training on the MiGs, but were generally ineffective.

Those connections enabled him to challenge Soviet advisors and demand greater operational flexibility for himself and other pilots of his unit.

His initial solution based on Soviet manuals consisted of rapid descending turns followed by a sudden activation of the afterburner and a climb.

However, during a test flight in early 1967, Mohammad inadvertently pitched the nose of his MiG-21 too hard, so that the forward movement of his aircraft nearly stopped.

In reaction, he engaged the afterburner of his MiG, and ended with the plane standing vertically on the verge of stalling out of control.

Intrigued, he decided to try to replicate the maneuver in a controlled manner, this time by engaging the afterburner beforehand, as the Tumansky R-11 engine of the MiG-21 had to spool for full effect.

[17] The Syrians named the cobra the "zero-speed maneuver" (Arabic: مناورة السرعة صفر "munawarat alsureat sifr").

However, unlike a regular climb, this still achieves the effect of the cobra and the aircraft will still stall momentarily which lowers speed and momentum.

[20] It is a variation on the cobra maneuver where the aircraft performs the pull-up, but instead of returning to level flight applies rudder or thrust vectoring and turns downward.

The aircraft achieves a negative angle of attack, ending the maneuver in a dive, therefore regaining airspeed sooner than the common cobra.

[21] Unlike VIFFing, however, the fully developed cobra maneuver leaves the aircraft in a precarious and non-offensive attitude, with no energy, with weapons pointing toward empty sky and with the pilot having lost sight of the enemy.

While entering the cobra is effective as a "speed brake" maneuver, usefulness in combat is limited at best, and then only if exited while sufficient energy remains to bring the weapons to bear before the opponent can break into an evasive maneuver—or, worse, loop back and attack.