Eject, Eject, Eject!

Date 13.9.2021

 

The in-flight rescue of pilots became a topic from the very start of war aircraft deployment. Dogfights, often resulting in a shot-down of one plane, usually called for the pilot’s bailout out of the cockpit. And while with the early biplanes the task was easy – open the canopy, unstrap from the seat and jump out – the first jets introduced to the service presented a challenge. The flight speed called for an automatic solution with the ability to overcome the airflow-generated pressure, which prevents pilots from a manual bailout. The solution is called an ejection seat, and it saved the lives of more than 13,000 pilots worldwide to date.

 

 

 

Since the Germans introduced the very first spring-powered ejection seats during WWII, the technology took a giant leap forward. The number of companies involved in seat development and testing has dropped over the subsequent years and, instead, airplane OEMs specialized seat companies captured the market. Currently, there are ejection seat manufacturers in the USA (Collins Aerospace), UK (Martin Baker), Russia (NPP Zvedza), China (Aerospace Life-support Industries) and the Czech Republic (Aero Vodochody Aerospace and Zlin Aircaft). As far as the market structure goes, the most dominant provider is the UK-based company Martin Baker, occupying just over fifty percent of the market. The remaining positions are held by Collins Aerospace and NPP Zvezda, with the Chinese manufacturer mostly responsible for the domestic market and the Czech companies playing a very local role with seats connected with out-of-production planes only (although some rebuilds were equipped with newly built seats). For the variety of ejection seat-equipped planes, the seat selection is very limited.

The UK OEM provides a wide variety of seats, a range called Mk.10 to Mk.18 (earlier models are not in use anymore) usually heavily customized for a particular aircraft and may be considered an industry benchmark. One can find those in the latest fighters such as F-35, European fighters such as JAS-39 Gripen and Eurofighter Typhoon, or training aircraft like L-39NG or Italian M-346. The company is rightfully considered ejection systems industry leader, with 7,650 lives saved since its first seats were introduced. Indeed, such primacy can be hardly overcome by any rival. The US Collins seat called ACES can be found in F-15, F-16, F-22 or B-2 airplanes. Due to the popularity of F-15 and F-16, the ACES seats also became very successful. Russian seats such as K-36 from Zvezda company became popular after unintentional ejections during spectacular air show crashes in the early 1990s and still present the only option for all Russian planes, regardless of their OEM. The Chinese HTY-5 seats, heavily influenced by Martin Baker types originally delivered to China in 1980s and 1990s, are equipping domestic fighters and were also used in some F-7 fighters (unlicensed copy of MiG-21). The Czech seat VS-2 is now used only in L-159 type, as the subsonic character of the seat and its unique logistics footprint make it less interesting for other plane makers.

Technical aspects

The seat itself is just the core of the rescue system. For a pilot to be ejected, several steps have to occur. At first, the ejection path has to be cleared, either in the form of a canopy jettison or its transparency scattering. The jettison is usually used with many types such as F-16 or F-18, where the transparency is so tough that the detonating cord might not be able to cut through it. So, the whole canopy with frame and glass in it is jettisoning by means of pyrotechnic cartridges. Should the glass be less thick, the canopy fragmentation used is one known from many training planes, including the latest L-39NG or BAE Hawk. The canopy transparency is scattered by an explosive cord cutting into small pieces. Should the ejection path be clear, the telescopic cartridge seat gun is activated, and the seat is elevated above the cockpit. The elevation is preceded by a proper automatic strapping of pilots via many mechanically, pyrotechnically or electrically powered reels (shoulder and lap harnesses are tightened, the legs are restrained by special ropes or hands are restrained, etc). Once the seat is above the cabin, the rocket engine is initiated. It boosts the seat and lifts it away from the plane with up to 22g force applied on the pilot’s body. The ejection is also very noisy, with over 120 dB in peak. Once the seat is in a safe distance from the plane after the rocket boost, the automatic sequence deploys the small parachute to help stabilise the seat and subsequently deploy the main one. The parachutes stabilise the seat with the pilot in “legs down” position and the sequencer dispatches the ejection seat from the pilot. The pilot then lands with his parachute. The whole ejection process is automatic, should the pilot not be able to perform any task (for example with a tandem crew, the ejection of both pilots may be activated by either member in many planes).

The seat itself is not very comfortable, as the pressure on the spin has to be minimized during the ejection, so the seat cushion is not very soft. Should the plane be equipped with an ejection path clearing mechanism as described above, the seat may usually work in zero-zero conditions, i.e. with zero altitude and zero speed. The upper limits of the ejection easily exceed 1,100km/h and 15,000m, but for such extreme conditions, the overpressure suit and breathing support are essential. The pilot has to wear a special flight suit, which is inflammable and provides protection against burns. Also, the flight helmet must support the ejection as, for example, some items like NVG goggles are exceeding the neck forces and have to be removed prior to ejection. With women entering the military aviation world on a large scale, the seats have to be able to absorb a large span of the pilot´s weight and anthropometric limits. For example, the US requirements now expect the pilots to weigh anywhere between 55 to 120 kg with a height ranging from 1,55m to 1,95m. With such a wide range, the newer seats have adjustable thrust coping with the actual weight. Also, the increasing weight of the pilot helmets (equipped with more and more sensors) means the most recent seats, such as the US ACES 5 type, are equipped with a new passive head and neck system, allowing to cope with the new gear.

 

Text by: Jakub Fojtík, Ph.D., LL.M.
Photos by: Martin Baker, UTC, NPP Zvezda, author

Stay up to date

with the latest news from Aerospace!

Your email address will only ever be used for Newsletters campaings with the legal agreement of your Privacy Policy. You can change your email preferences or unsubscribe in every email if you no longer wish to receive emails from us.


TOP Interviews

Catalyst =  20% lower consumption & 10% higher power for Eurodrone

Catalyst = 20% lower consumption & 10% higher power for Eurodrone

Date 30.3.2022

fl_en|fl_cs

Catalyst – 100% European development without any US licenses. Ecologically more effective thanks to 20% lower consumption and 10% higher power. This means three more hours of time in the air,  which can be decisive in various defense actions and even save lives.     Within a few weeks, Airbus Defense and Space will have […]

TUNGSRAM: innovation is in our bloodstream

TUNGSRAM: innovation is in our bloodstream

Date 6.4.2022

fl_en|fl_cs

Tungsram – an iconic name – returned to the global market in 2018 as an innovative, premium European brand with the acquisition of GE Lighting’s Europe, Middle East, Africa, and Turkey general lighting business along with the global automotive operation. Tungsram, originally established in 1896, is a brainchild of the 2nd industrial revolution – resulting […]

Our sea is in the (Virtual) air

Our sea is in the (Virtual) air

Date 8.9.2021

fl_en|fl_cs

The Path of a Czech Virtual Reality Headset into the Latest Western Fighter   Military pilots are no longer the movie hot shots seen in Top Gun or similar Hollywood blockbusters. Today, cadet pilots don’t just learn to fly but work as an operator within a network-like architecture of multiple aerial and ground elements including JTACs. […]

Another great accomplishment of the Grob G 120TP

Another great accomplishment of the Grob G 120TP

Date 16.3.2021

fl_en|fl_cs

The German Armed Forces have chosen the aircraft G 120TP to train its air force pilots at the Phoenix-Goodyear airport, Arizona. This adds one more air force in the world operating this modern trainer already and just another triumph to the company’s success story.   With more than 150 aircraft delivered to their customers already and […]

Show more

Stay up to date

with the latest news from Aerospace!

Your email address will only ever be used for Newsletters campaings with the legal agreement of your Privacy Policy. You can change your email preferences or unsubscribe in every email if you no longer wish to receive emails from us.

More news

Saab and FMV Sign Contract for new Gripen Launch System

Saab and FMV Sign Contract for new Gripen Launch System

Date 3.5.2022

fl_en|fl_cs

Saab has received an order from the Swedish Defence Materiel Administration (FMV) for the development and integration of a new launch system for Gripen C/D and Gripen E. The order, valued at approximately SEK 400 million, was placed during the first quarter. The order includes the development and integration of a new launch system for […]

EVEKTOR REVEALS SPORTSTAR RTC WITH ROTAX 912iSc  & NEW HIGH-TECH COCKPIT AT AERO 2022 

EVEKTOR REVEALS SPORTSTAR RTC WITH ROTAX 912iSc  & NEW HIGH-TECH COCKPIT AT AERO 2022 

Date 28.4.2022

fl_en|fl_cs

The first day of Aero Friedrichshafen 2022 was opened yesterday. During Evektor´s Grand Opening Ceremony the company CEO Mr. Martin Kárník introduced a new facelift of EASA certified SportStar RTC aircraft and further direction of innovations & Evektor aircraft development.   The exhibited SportStar RTC is newly equipped with a Rotax 912iSc Fuel Injected engine providing […]

The company Aircraft Industries – LET Kunovice passes into the hands of the Czech Group OMNIPOL

The company Aircraft Industries – LET Kunovice passes into the hands of the Czech Group OMNIPOL

Date 27.4.2022

fl_en|fl_cs

The largest manufacturer of civilian transport aircraft in the Czech Republic, Aircraft Industries, is returning to Czech ownership after 14 years. On April 21st, 2022, the Russian owner and the OMNIPOL Group agreed to sell 100% of Aircraft Industries shares to the Czech company OMPO Holding. Intensive cooperation between the OMNIPOL Group and Aircraft Industries […]

Aero will deliver twelve brand new L-39NG jet trainer aircraft to the Hungarian Defence Forces Command

Aero will deliver twelve brand new L-39NG jet trainer aircraft to the Hungarian Defence Forces Command

Date 21.4.2022

fl_en|fl_cs

AERO Vodochody AEROSPACE a.s. (Aero) has signed a contract for  the delivery of twelve L-39NG jet trainer aircraft and related support services with the  Hungarian Defence Forces Command. The first aircraft will be delivered to the  customer in 2024.  The Czech manufacturer will deliver a total of twelve aircraft, with eight aircraft delivered in  the […]

Catalyst =  20% lower consumption & 10% higher power for Eurodrone

Catalyst = 20% lower consumption & 10% higher power for Eurodrone

Date 30.3.2022

fl_en|fl_cs

Catalyst – 100% European development without any US licenses. Ecologically more effective thanks to 20% lower consumption and 10% higher power. This means three more hours of time in the air,  which can be decisive in various defense actions and even save lives.     Within a few weeks, Airbus Defense and Space will have […]

US military plane Osprey down in Norway during NATO exercise

US military plane Osprey down in Norway during NATO exercise

Date 19.3.2022

fl_en|fl_cs

A US military aircraft with four crew on board is thought to have crashed in Norway while taking part in NATO exercises, Norwegian emergency services said on Friday. The US Osprey aircraft “was reported missing at 18:26 (17:26 GMT) south of Bodo” in northern Norway in bad weather, the regional emergency services said in a […]

Show more
Subscribe to our magazineRegister now