The pilot's last patron saint - ejection life-saving system

The movie "Lord of the Skies" depicts the romantic and risky life of a test pilot. Every exploratory test flight is extremely dangerous, so the aircraft life-saving system is undoubtedly the last guardian of the test pilot's safety.

When an unexpected situation occurs during high-speed flight and the pilot has to leave the aircraft, the life-saving system must allow the pilot to leave the aircraft as quickly as possible under the impact of the high-speed airflow and strive for a sufficient height to open the parachute. Therefore, when the pilot escapes from the aircraft, the canopy needs to be thrown away, the pilot ejected from the cockpit, and pushed to a height high enough to safely open the parachute.

Pictured: The ejection seat of a fighter jet in an experiment (Source: Sohu)

Pictured: The ejection seat of a Chinese fighter jet at the air show (Source: Sohu)

The canopy of a fighter jet consists of a fixed front section and an openable rear section. The rear section of the canopy is opened and closed using an opening and closing pneumatic system and a hydraulic system. When opened normally, the rear section of the canopy first moves a few centimeters backward, disengages the locking mechanism, and then flips upward. When ejecting and parachuting, the canopy needs to be jettisoned in an emergency. There are two ways to jettison the canopy in an emergency. One is to pull the emergency jettison handle on the cockpit wall to jettison the canopy mechanically; the other is to directly pull the ejection ring on the seat and simultaneously connect the mechanical and electrical methods to jettison the canopy. By jettisoning the canopy, the ejection channel is opened, and the task of quickly leaving the aircraft is given to the ejection seat.

The ejection seat is not only the pilot's working seat, but also a life-saving device to ensure the pilot can leave the aircraft in an emergency at various altitudes, speeds and conditions. As can be seen from the movie "King of the Skies", the ejection seat consists of a seat, a headrest, a mechanism box, an integrated ejection mechanism, a life-saving system, a pilot emergency restraint system, and a pilot auxiliary protection system (as shown in Figure 3).

During ejection, the pilot pulls the ejection ring, the protective goggles on the helmet automatically drop down, and the tensioning mechanism and arm stopper of the emergency restraint system firmly fix the pilot on the seat. Among them, the shoulder and waist tensioning mechanisms constrain the pilot to the seat; the leg lifting mechanism and leg tensioning mechanism lift, retract and fix the pilot's legs; the arm stopper constrains the pilot's arms to prevent the high-speed airflow from blowing the arms away and causing injury. The integrated ejection mechanism is powered by a rocket engine and adopts a two-stage ejection. The first stage ejection pushes the seat up along the guide rail and pulls the safety pin; the second stage ejection pushes the seat up to the required height. After the seat is ejected from the cockpit, the stabilizing parachute of the seat stabilization system keeps the seat stable. After reaching the set height, the automatic parachute opener connects to the parachute gun of the parachute opening mechanism, throws away the headrest, and the shoulder strap tensioning mechanism cutter works to separate the pilot's strap system from the seat; then the parachute box opens, tows and opens the lifesaving parachute. Subsequently, the waist belt and leg strap cutters work, the pilot is separated from the seat, and lands safely on the ground with the lifesaving parachute.

Figure 3 Typical ejection seat structure of a fighter jet

The plane in distress during the test flight in the movie "The King of the Sky" was a two-seater. The ejection rescue of a two-seater aircraft can be set in two modes: single-seat ejection and linked ejection. During ejection rescue, the front and rear cabins are ejected in sequence at a certain interval, so as to avoid the front and rear cabins from colliding in the air during ejection.

Wang Mingzhi, a military expert, joined the Air Force in June 1980, received a master's degree in military science in 1991, and a doctorate in military science in 2000. He was a professor at the Air Force Command College and held the rank of professional technical colonel.

Produced by: Science Popularization China

Producer: Guangming Online Science Department

Author: Wang Mingzhi (military science writer)

Scientific review: Fei Boyu (senior military content editor)

Planning: Jin He