Why does ejecting out of an aircraft can cause back injuries?

Question

I've heard ejecting out of a fighter jet can cause back injuries which can be bad enough to make you not fly again.

So can it harm you and if so why does it?

Answer 1

With the ACES II ejection seats, back compression is not as severe as it was with older Martin-Baker seats.
Most aircraft built/designed since late 60s have ACES II seats in them. These seats have zero/zero capability. Meaning they can safely eject the pilot from aircraft at zero altitude and zero airspeed. They even have a gyro system to right the seat if the pilot ejects from an inverted attitude.
It is a very reliable system that any pilot would prefer to never have to use.

Answer 2

1

Answer 3

The ejection seat of any fighter jet has a sudden acceleration of around 11 g's.
That compresses the spine and internal organs. I have a friend who ejected from his fighter. His spine compressed him and he was a whole 2" shorter after leaving the hospital.
They do not train in actual ejection, only simulations.
A pilot may eject as much as twice but a third time would no doubt cripple a person.
The sudden forces cause trauma not only on the spine but it also stretches internal organs. He had a blocked intestine for two days and his sight was poor for three weeks. The poor eyesight was due to ruptured veins in the eyes.
He did gain back 1 1/2" in height in about 6 months.
Yes it is rough.

Answer 4

hi don't know about the western ejection seats, but those used in mig21 and other older russian jets are said to have a 35g load for a very short period of time. this may cuase spinal injuries, mostly commpressive fracturas vertebrae. typical warsaw pact pilot should have been sent to slow aircraft after two ejections -just because of possible injury during ejection. There is a documented story of a czechoslowak pilot who survived ejection without injury, but died after parachute landing - due to a shock and trauma he dressed off, and fell asleep, and he froze. so not only ejection itself may be dangerous

Answer 5

Newtons third law states that "To every action there is an equal & opposite reaction:. A pilot who presses the 'eject' button is at 'rest' (both plane & pilot have the same speed) when the live rockets underneath his seat propel him at such a speed that in the begining the pilot sinks in his seat because of the gravitational reaction. This force is so high that it requires mostly a very fit body and super-human strength to withstand the forces. The end of the backbone being supported by the v-section of the lower back bears all the brunt and it is the damage to this area which sometimes makes the pilot unable to regain his fitness as earlier. Other than this there have been instances when the cockpit canopy takes a little more time to open or may be floating along when the pilot head hits it during the upwards propulsion. This proves fatal in most of the cases...

Answer 6

You must be shot, ejected, out of the cabin in order to clear the air craft.

Most times, no injury occurs. The few times that injuries occur, it is the better than the alternative of going in.

While we had jets in the hangars for repairs, we had a few technicians, sitting in the pilot's seat, inadvertently activate the ejection seat hitting the hangar roof and killing them.

Now we use a safety device to prevent accidents in hangars.

Answer 7

It is less of an issue since the propellant changed from a cartridge to a rocket. Early seats (up to the early 70s) used what was effectively a large cartridge that went 'bang' and propelled the seat. The acceleration forces were large and rapid.

As the need for zero/zero seats arose (in part due to the development of the HS Harrier VTOL) the propellant was changed to a longer burning rocket. This allowed for more progressive acceleration and more importantly greater height so as to allow for parachute deployment.

Whilst back injuries are still possible, they are much less likely to be as serious with rocket propelled seats.

Answer 8

When you eject out of an aircraft, you have to accelerate out at a high rate to be able to clear the tail of the aircraft, or if at ground level, get to a height where the parachute will deploy safely. The rapid acceleration can be considered similar to increasing the gravity on your body. You spine will compress and bend, and if you are not seated proberly, your spine can be injured by contorting in unnatural ways.

Answer 9

it can cause injuries to your back because you have all that power underneath you, just like in a rear bumper wreck, you have that force you throw your head forward and maybe break your nose if you dont have airbags.
AS long as you stay flat against the seat during the ejection stage you should be fine, i've heard guys eject ten to twenty times and didnt have problems because its all about reptition getting it right otherwise you're gonna kill urself before you even crash.

Answer 10

Having worked with Life Support technicians, the force of the charges that blast the seat out of the aircraft are enough to compress the spine of the pilot. Pilots get 2 ejections before they are permanently grounded.