[krisoft]

What do you mean by “flight ejections”? Are we talking about ejection seat activations in military aircraft?

This factoid sounds very suspect. Doesn’t most people who need to activate an ejection seat survive spleen or no spleen? Deaths may occur of course, an ejection is not without risks, but if everyone or nearly everyone with a spleen dies then my understanding of the risk associated with an ejection is seriously miscalibrated.

Also the group of “active military pilots who had their spleen removed” must be a small group, likewise “military pilot who needed to activate an ejection seat” is a small group (but probably a bigger one than the spleenless group). So one would expect that there is almost nobody in the intersection of these two rarefied sets.

Obviously this is all very handwavy reasoning, so who knows. But if you have a source that would be highly appreciated.

[kayodelycaon]

Ejection seats are likely to cause spinal fractures (20~30% by one study) and broken legs (no numbers). Tests on the F-35 showed lighter pilots could have their necks broken by the heavier helmet, so they had to add a switch that will slow down the ejection sequence.

https://www.popsci.com/what-aircraft-ejection-is-like/

[sokoloff]

The risk of injury in ejection is quite a bit higher than most people expect (typically over 25% towards 50% for older tech ejection seats). It’s still a way better scenario than riding it in.

It is not uncommon for an ejection to end a pilot’s tactical jet flying days for medical reasons.

[dbcurtis]

> It is not uncommon for an ejection to end a pilot’s tactical jet flying days for medical reasons.

This exact thing happened to a friend of mine. Combat-rated Harrier pilot in the RAF. Had to punch out after a bird strike. Came out of the infirmary 4 months later, 1/2 inch shorter, flying career over.

[krisoft]

> The risk of injury in ejection is quite a bit higher than most people expect

I agree with you on that. But the question here is risk of death, not risk of injury.

I don’t have reliable statistics but found this[1] article which says about ejections: “If you look at statistics around the world, the survival rate is greater than 92 per cent.”

1: https://amp.smh.com.au/education/how-dangerous-is-it-to-ejec...

[Hallucinaut]

Obviously if you're ejecting at or near supersonic speeds there are other stresses, but if the trauma is mainly from the ejection booster itself why is it still done with such force?

It seems like a majority of ejections shouldn't be benefited by half a second less time to achieve clearance (or the jet itself could detect altitude and adjust the speed to increase survivability).

I'm guessing this is also a function of trying to achieve lateral separation from the ensuing fireball in a crash but it surprises me rates are so high for injury.

[TylerE]

Because you have to get up and over the tail of the airplane without it slicing you like a cleaver.

[londons_explore]

A cleverer ejection seat could track the tail and body of the craft, and adjust the rocket force based on the trajectories in each case.

Then you don't have to use enough force to avoid the tail in every case, but merely enough force to avoid the tail in this case, which will normally be far less.

[sokoloff]

The aircraft being exited is often not in a factory nominal condition.

[TylerE]

Solid fuel rocket, so no throttle.

[krisoft]

Yes. And if someone is curious why are we using solid fueled rockets in this application:

The big benefit of solid fueled rockets is that they are very reliable, and require no maintenance. They are basically a big “candle” composed of a mix of fuel and oxidizer. You can lit it a day after it was made or twenty years later it will work the same.

The liquid fueled options have valves and other moving parts which can jam, corrode and degrade with time. So it would require frequent maintenance and would still be likely less reliable than the solid fueled variety.

[HPsquared]

You could use an array of motors, and only activate however many are needed.

[samatman]

While I'm unaware of an ejection seat which blows the tail off the aircraft backward with another shaped charge, there's nothing preventing this.

[alanbernstein]

Of course there is: whatever event warranted the ejection. The seat/canopy mechanism is relatively localized within the aircraft, adding one more system to fail is perhaps frowned upon in this absolute last-chance survival system.

[AvocadoPanic]

Doesn't everyone remember what happened to Goose?

[inglor_cz]

An ejection seat is basically a rather powerful small rocket with huge acceleration - much more forceful than what astronauts nowadays experience. Human bodies aren't built for riding such rockets. Injuries from ejections are pretty common and some of the ejectees are never fit to be combat pilots again.

[krisoft]

Yes, ejections are violent. Can cause injury, can cause death. No question about that.

Spinal injuries are likely and ejections frequently end the flying career of pilots for medical reasons.

What does this have to do with the claim in question?

They claimed “people who survive flight ejections and hitting water at high speed tend to have had their spleens removed”

This implies that if you look at the group of people who survived a flight ejection (over water and hit the water at high speed) you would find that most have no spleen. Do you find this plausible?

[inglor_cz]

A trauma surgeon would be a better fit to answer that question, but crushed spleens seem to be common in high speed impacts (car crashes, falls from ladders etc.), at least as far as I can judge it from my limited circle of friends who have had such experience.