- Published on Monday, 26 November 2012 09:00
As fighter aircraft developed from propeller-driven to jets, it was evident that the traditional way for pilots to escape aircraft was no longer quick enough. Releasing the cockpit canopy, opening the safety harness and then leaving the aircraft took too long in relation to the flight speed. That’s why the ejection seat was developed.
I am sometimes asked about the possibility of ejection seats in commercial aircraft, and I thought I’d write a blog on this subject, as it which appears to be of interest to our readers.
Safety first. With present technology only a pyrotechnic solution is sufficiently powerful for propelling an ejection seat. A couple of kilos of explosive on an aircraft is a considerable risk, however. A misfiring caused by a human error or technical fault could be fatal – whether it happened on the ground in connection with maintenance or during a flight. I recently read an article on the subject, which described how a reporter travelling as a passenger in a jet fighter during a demonstration flight in South Africa ejected himself out of the aircraft by accident during the show.
Explosives loaded onto an aircraft also increase risk in emergency landings, aborted take-offs, small inflight fires and in other situations that generally do not result in fatalities. I dare not think, moreover, what terrorists could achieve if they were able to get their hands on such explosives during a flight.
Even if we were to devise a safety way of propelling the ejection seat, many problems would still remain. The ejection of passenger seats would have to proceed systematically from the rear to the front of the aircraft (lasting 15-20 seconds), so that the seats would not interfere with each other during the ejection process. Even if this, too, could be achieved, the result would still be hundreds of out-of-control passengers falling through the air, many of whom would still be trying to get out of – their already ejected, of course – seats.
Due to g-forces, oxygen deficiency and non-existent control, survival would be challenging, and passengers would also have to be able to use their parachutes and descend correctly onto land or water. Although ejection seats, nowadays, are fairly automatic, the fighter pilots that use them receive very thorough theoretical and practical jump training.
Aircraft, too, would have to be redesigned and recertified: floors would have to be strengthened, overhead lockers removed, and ejection openings added to ceilings. One fighter jet ejection seat costs around 100,000 euros. A new passenger seat –which would, of course, require, an entertainment system – wouldn’t cost any less. The already huge prices of aircraft would rise further. The size of the seats would also mean a lower number of passengers on each flight. The ejection seat, weighing more than 100 kilos, would increase the weight of the aircraft and therefore fuel costs. As a result of all these factors, ticket prices would have to be many times higher than now.
Taking the present safety statistics into account, I don’t believe that passengers would want to pay such sums for their tickets only to find themselves wearing shoulder-straps, feet and hands restraints, helmets, oxygen masks and life vests just in case of a possible ejection – with no baggage or cabin service, either. And don’t even think about visiting the toilet.
Accidents in which ejection seats would have saved human lives are extremely rare. On the other hand, a controlled emergency landing or a skid off a runway will in all probability not result in fatalities. There are many examples of this: in recent times, for example, there have been the AF358 in Toronto and the BA038 in London in 2008 as well as the landing of the US1459 on the Hudson River in New York last year. The cabin seats of a commercial aircraft are designed to withstand the stress of an emergency landing, and the emergency exit systems enable an aircraft to be evacuated in 90 seconds. Crew receive annual evacuation training.
Expanding the idea still further, one could imagine that traffic fatalities would increase if ejection seats were fitted to passenger aircraft. Higher ticket prices would drive some passengers to less safe ground transport.
Finnair monitors the development of flight safety and is ready to accept new ideas to improve safety. The future will tell whether it may be possible to design an ejection seat that would be usable in passenger traffic. Then Finnair will surely once again be among the first to adopt the new technology – as it has been many times before.