NDTV Explainer: How Pilots Eject From An Unrecoverable MiG-29 Jet

A MiG-29 fighter jet crashed in Rajasthan's Barmer yesterday during a routine night training sortie. The pilot ejected safely. 

The Indian Air Force said the MiG-29 fighter jet faced a "technical snag" during the night sortie, and a court of inquiry has been ordered. There was no loss of life and property. The pilot crashed the jet away from a residential area around 10 pm last night.

MiG-29, NATO name 'Fulcrum' and Indian name 'Baaz', is an air superiority fighter jet originating in Soviet Russia. It was formally inducted into the Indian Air Force in 1987, initially with two squadrons - No. 28 and No. 47 Squadrons. The MiG-29K fighter jets deployed on the Navy's aircraft carriers are currently the mainstay of the Navy's fighter operations. They will be replaced by the Tejas fighter jet.

How do pilots eject from a fighter jet?

The Zvezda K-36D zero-zero ejection seat is onboard the MiG-29 fighter jet. It is considered one of the most advanced ejection seats in the world and is also deployed on Air Force Su-30MKI fighter jets. 

The seats are designed to eject pilots from zero position, i.e. stationary position to a considerable height to deploy parachutes. Zero position refers to zero altitude or zero speed. The development of Martin-Baker zero-zero ejection seats by the British (the West) eventually led to the development of zero-zero seats by the Soviets. The Tejas fighter jet has the Matin-Baker zero-zero ejection seat deployed. 

The zero-zero capability was developed to help pilots escape unrecoverable situations during low-altitude or low-speed flights and ground mishaps during takeoff or landing. 

The ejection seat is part of the overall 'Egress' system, which means the "way to exit". The system includes explosives under the seat, the canopy, and parachutes. 

When the pilot pulls the ejection handles (in the case of K-36D, they are located in the front of the ejection seat), the canopy of the aircraft is jettisoned. The explosive cartridge catapults the seat along the guide rails, and a leg-restrain system is activated. It protects the pilot's legs from getting caught during the ejection. The rocket propels the pilot to a considerable height, at least 300-400 feet so that ejecting pilot avoids the tail of the plane, which is rapidly descending. When the seat and the pilot are separated, the harness and the pilot are released from the seat and the parachute deployment signal is activated which automatically opens the chute.

The angle of ejection is crucial. The fighter jet moves forward and the line of ejection is perpendicular to it to move the pilot away from the aircraft. 

The entire exit process occurs in less than 10-15 seconds - From the pulling of ejection handles to the deployment of parachutes. The pilot in yesterday's crash would have experienced high-G forces during ejection. 

When K-36D Caught The World's Attention

The US Air Force Materiel Command at the Wright-Patterson Air Force Base in Ohio conducted a comparative testing study to understand the components of the K-36D ejection seat with its US counterpart. The interim report published in 1993 and 1994  gave an in-depth analysis of the K-36D seat. 

The K-36D ejection seat gained wide attention at the 1989 Paris Air Show when the pilot successfully ejected from a MiG-29 from an extremely low-altitude engine failure.

The system has been a standard of Russian high-performance aircraft, and the seats have an impeccable record of survivable ejection from speeds of 0 to 755 Knots of Equivalent Air Speed (KEAS). 

In 1989, the pilot ejected from the jet after an engine failure at an altitude of 300 feet, with an 80-degree pitch-down altitude, the speed of the aircraft was 100 knots (185 km/hr). The pilot ejected, and the parachutes were deployed just 15 ft above the ground. He survived and suffered minor injuries. The incident caught the US' attention and it later analysed the K-36D ejection system in detail. 

Understanding The Ejection Seat System 

The K-36D ejection seat is designed by the Zvezda Design Bureau in Russia. It is said to be strong with the integration of ejection seat subsystems such as windblast protection, leg and arm restraints, leg lifters, and a vented helmet, which is designed to interface with the seat headrest. 

The K-36D and the flight equipment, such as the pressure suit and helmet, were designed together as a single system, the report said.

The seat is incorporated with telescoping stabilization booms, which ensure aerodynamic stability. The other subsystems that have been integrated into the total design seat include the windblast deflector, rocket propulsion system, crew recovery parachutes, restraint devices and sequencing systems. 

The K-36D ejection system is advertised by the Russians as an advanced ejection seat, providing survival of the pilot up to Mach 3 speed and 80,000 feet altitude. 

The stabilization booms in K-36D play an essential role in providing safety for the pilot. In yesterday's ejection, the telescoping stabilization booms, installed at an angle of 15 degrees from the seat flight, extended pressure to assist in keeping the seat stable from the time it separated from the aircraft until parachute deployment.

The other key components are leg lifters, leg restraints, and windblast deflectors - Additional protection against the aerodynamic forces experienced during ejection, restraint systems, helmet and headrest and arm paddles.

The K-36D receives its parachute deployment signal from the aircraft airspeed and two onboard altitude pressure/timing devices. The parachute inflates automatically after seat and crewmember separation. The survival kit remains attached to the crewmember during descent.

The test results conducted by the US concurred that the K-36 ejection system provides superior-high-quality stability, adding that the team that has developed the K-36D has a solid understanding of the scientific principles behind the system's operation.