A Question About Ejection Seats

[V2-OMG!]

I've just finished John McCain's memoir, Faith of the Fathers,
which deals with his Vietnam/POW experience.

After a SAM blasted off the wing of his F-4, he was able to eject, but fractured his arm and leg in several places in the process. This was also a common plight of his fellow POW pilots (if the force of the ejection didn't kill them first).

My question is this: Have ejection seats become more "user friendly" if I can call it that? In thinking back to McCain's experience, even though he had been trained to survive hostile territory and/or severe terrain, what good would it be to him or others when crippled by serious injury due to the ejection seat which ironically, was designed to reduce pilot casualties?

Thanking you in advance for your answers!

[LuckyBreak]

When you said 'if the force of ejection didn't kill them first', Martin Baker, who make all the RAF seats, claim that no-one has ever been killed by one of their seats if used within parameters. As for more modern seats being more user-friendly, I believe that they are - example being the Typhoon's Mk16 seat which has a much more progressive acceleration than previous seats.

[Timelord]

Seats of the Vietnam era (wasn't McCain's an A4?) were powered by a cartridge. One bang had to be enough to get you clear of the fin and high enough for the seat to function. Therefore it had to be a pretty BIG bang. If,say, your thigh was an inch or two above the seat pan because, for example you are countering a violent roll, then the impact of the seat as it goes up is likely to break a bone. Modern seats are initiated by a smaller charge and then a smoother rocket fires to get you the height so it is slightly less violent (not that it feels that way).

However, if battle damage causes an aircraft to go violently out of control and you eject into a high speed airflow it is that blast that causes arms and legs to flail and get damaged. I think all seats have leg restraints now and some aircraft (Tornado for example) have arm restraints that hold your arms in until the airflow is reduced.

Of course arriving on the ground is another, equally painful, story.

The bottom line is that any ejection injuries are probably preferable to the alternative.

[Always a Sapper]

V2-OMG! This place (http://www.ejection-history.org.uk/) may also be worth checking out...

[V2-OMG!]

When you said 'if the force of ejection didn't kill them first', Martin Baker, who make all the RAF seats, claim that no-one has ever been killed by one of their seats if used within parameters. As for more modern seats being more user-friendly, I believe that they are - example being the Typhoon's Mk16 seat which has a much more progressive acceleration than previous seats.

LuckyBreak, ironic handle, considering the question, huh? Okay. I tend to get a bit over-dramatic, re: "the force of the ejection didn't kill them first." I am happy to hear that no ES has actually killed a pilot. "Progressive acceleration" - now, I like that term. Thanks for your reply.

Timelord, I enjoyed your informative professional reply; thank-you so much. And yes, McCain flew the A4 Skyhawk, not the F4. Loved your reasoning about the "alternative."

Always a Sapper, that is an invaluable link - thanks!

[L J R]

And I hear that even the B2 has them nowerdays....

[RJ Kanary]

There's a smoking hole somewhere that's missing two seats.:(

And it's a good thing there were there in the first place . :)

[seekayess]

. . . . and the special raised-arms 'ejection' seat for Navigators flying with a fighter pilot . . . .





http://www.assistivedevicesinc.com/images/raised%20toilet%20seat.jpg

[NRU74]

Seek
That's clearly not the bog standard seat

[cazatou]

V2-OMG

In the mid 60's (when I started Flying Training) the Martin Baker seat in the Jet Provost was fired by a cartridridge giving a 60ft/sec/sec acceleration. In the early 70's this changed to an 80ft/sec/sec acceleration (bigger cartridge).

This change gave rise to an increase in back injuries partly caused by the fact that the pilot sat on a "soft" canvas survival pack. The pack was redesigned and enclosed in a rigid fibre glass container which reduced the chance of back injury. This, of course, had to sit in the same space in the ejection seat and being rigid offered slightly less internal space for survival aids.

The result was that the "Poncho Cape" - a waterproof cape that was "Dayglo orange" on one side and black on the other (use depending on whether you were evading capture or trying to capture the attention of rescuers) - was removed and replaced with the "North European Mosquito Net" as that was the only item readily available that fitted the space. Exactly what was needed on the north York Moors!!

[V2-OMG!]

Caz, I gather your reference to the necessity of a mosquito net in the North York moors was tongue-in-cheek, and would be akin to finding a pair of snowshoes and a fur-lined parka in the "survival pack" after being shot down over Iraq.....right in the middle of a 45C. summer.

The fiberglass shell would certainly offer more support. If I can use the analogy of those hurly-whirly amusement park rides which accelerate at tremendous speed - you will notice that the riders sit in a fiberglass "seat"....much like you described.

Thanks for adding to some of these great replies!

[V2-OMG!]

http://www.assistivedevicesinc.com/images/raised%20toilet%20seat.jpg
http://www.pprune.org/forums/images/statusicon/user_offline.gif http://www.pprune.org/forums/images/buttons/report.gif (http://www.pprune.org/forums/report.php?p=3941116)

seekayess, whew! At first blush, I was wondering if your imagery was a reflection upon the character of the question submitted. But....it obviously didn't "crap out" completely, as I have gleaned some invaluable insight.

BTW, I suppose the "progressive acceleration" forces of that "seat" would
be exponential to the "bang quality" of the ejectee's flatulence?

[cazatou]

V2-OMG

I am afraid that this is yet another case of truth being stranger than fiction!!

It's a bit like the Labour MP demanding to know why the RAF put condoms in the survival packs for aircraft operating in the Far East. He flatly refused to believe that you can (with care) get a couple of pints of water in a condom - very useful if you forgot to take a water bottle with you on ejection. They also help to prevent leeches from getting to those parts you would rather they didn't reach.

[V2-OMG!]

It's a bit like the Labour MP demanding to know why the RAF put condoms in the survival packs for aircraft operating in the Far East. He flatly refused to believe that you can (with care) get a couple of pints of water in a condom - very useful if you forgot to take a water bottle with you on ejection. They also help to prevent leeches from getting to those parts you would rather they didn't reach.


Perhaps the Conservatives should keep a few water-filled condoms handy in the House of Commons so the next time a Labour MP wishes to make a similarly idiotic stand.....he will quickly and most effectively have one of those two-pint rubbers rammed right down his throat.

Politicans. Now....they are another kind of "leech," and wouldn't it be nice if they could not get to those parts you would rather they didn't reach?



Life's a short runway - use it all.

[jimgriff]

And of course don't forget the wonderful

www.ejectorseats.co.uk (http://www.ejectorseats.co.uk)

for all things related to this wonderful subject:}

I'm still looking for stories, contributions, suggestions etc to add to the site.

As far as comfort is concerned you have to remember that compared to days gone by, aircrew are expected to sit on the seats for much much longer. What with AAR and the like it is not uncommon to be on the seat for huge amount of time and what with advances in foams and other materials the comfort is much better. Advances in explosives and rocket thrust dynamics are also more advanced with progressive burn compounds and the like being used providing better tollerated and predictable thrust curves.
The latest Mk 16 seats have one rocket which can "alter" thrust to compensate for all weights of user and give consistent thrust across that user spectrum.:8

Parachute design has also allowed for better results at both low and high speed deployment which also makes for a more comfortable letdown.

[cornish-stormrider]

Us humble lineys could always tell pilots that had ejected as opposed to those who hadn't.......yet.

The former were meticulous in their seat checks and strapped in a hell of a lot tighter than the latter, they demonstrated a somewhat laisasise faire (sp) attitude.

I know when I had a backseat ride, i could not get the straps to go any tighter. It felt like being in a fetish club :ok::E. awesome ride though (and no I'm not going to tell about the other one)