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The ejection seats on the F-35 Joint Strike Fighters are faulty... 1

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JohnRBaker

JohnRBaker

Mechanical
Jun 1, 2006
37,266
It appears that the Martin-Baker ejection seats installed in F-35 Joint Strike Fighters have been found to be faulty. The 'cartridges', that when ignited, propels the pilot's seat out of the cockpit, were found to not contain the material needed to set off the charge, and they've known this for three months but have just now grounded the planes:

Most US F-35s temporarily grounded as ejection seat issue threatens jets worldwide

Air Force discovered defect in April but didn’t know its full scope


John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Has there been an airplane design that's easily ejected from?
 
This is a bit more serious than that. No bang to throw them out.

Kudos to the squibber that noticed the suspect weight.
 
It's curious that there was not an inspection system that would automatically reject a failed cartridge.

In this case, not only was there multiple failures to "fill", but also multiple failures to catch the fact and do a rejection. There should have been a failsafe inspection of every cartridge.

I am also surprised at the duration of this episode. Three months to determine IF this was an isolated incident? Nope. A week. Info blast to all concerned: check these parts and report immediately! Then a preliminary investigation for another week--we visit the production facility and let them explain how this happened and how it will be fixed and how it will never happen again.


spsalso
 
There was something similar loading up tanks to go to Gulf 2 on boats.

One of the crane operators queried why some of the tanks were 15-20 tons lighter than others.

Got told to mind his business by the young tankie officer. When he spotted a sgt wandering around went and told him.

All hell lets loose because the sgt immediately recognised that the light ones were training tanks not war tanks with full amour
 
It's curious that there was not an inspection system that would automatically reject a failed cartridge.
Click to expand...

These are one-time use cartridges.

We did something similar with a leaky gas bottle that had to be weighed, in-situ, to determine if it was still usable; 50-lb object missing about 0.5 grams

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Are these sealed units? then, how would you test them? [ponder]

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Destructive test by some skip lot criteria.
Non destructive test for fill could be weight or X Ray on the production line.

Government specifications here usually have detailed requirements.
 
Thanks...

So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
If there's a weight issue, it seem rather easy to find...

I’ll see your silver lining and raise you two black clouds. - Protection Operations
 
My younger self shrugs while rolling into combat in unarmored ground vehicles.
 
Are these sealed units? then, how would you test them
Click to expand...

If the ignition charge is missing, then you could hypothetically weigh the canister and see if it's lighter than it's supposed to be. Alternately, you could possibly x-ray them

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
 
Yes.

You can do that.

Seems kind of obvious after the fact.


spsalso
 
" The military had tested 2,700 F-35 ejection seat cartridges and discovered three failures as of Wednesday,"
so a random/lot check could have missed it.

Jay Maechtlen
 
What about military hardware was designed to be safe? The fact of an ejection seat just may be safer than not having one is a thing.
 
"...why some of the tanks were 15-20 tons lighter than others....All hell lets loose because the sgt immediately recognised that the light ones were training tanks not war tanks with full amour"


This has lingered in my mind, and remains hard to believe.

That 15-20 tons isn't (mostly) bolted on. It's integral to the design of the machine. You would have to redesign the whole structure to use radically thinner material. So you'd have a huge added expense, combined with making a tank that couldn't ever be used in warfare. If it WERE bolted on, it would be obvious that something was missing during a visual examination.

I would question how useful a training tank that was lightened that much would be. Maneuverability would be radically different.

If you want a training tank, have them take out one of those clapped-up items over there.....


spsalso


 

quote:

" The military had tested 2,700 F-35 ejection seat cartridges and discovered three failures as of Wednesday,"
so a random/lot check could have missed it.

/quote

These are not items that should be randomly checked. EVERY ONE should be checked. And SHOULD HAVE BEEN. There is no excuse for letting any of these through.

Note that the first discovery was by a guy who felt the item in his hand felt light. A simple scale would have found this.

I think the president of the company should make visits to the crews who use this equipment and make a personal apology for screwing up and endangering their lives.


spsalso
 
They are different apparently and don't have the reactive armour fitted. Just dumb boxes. Also they have training NBC kit.

They can fire and have the weapons systems and coms.

I think all the ones in Canada are also training fit.

Saves a fortune in fuel.


Combat fit is 75 tons
Training about 60 tons.


 
The existence of a training tank would seem odd to me except its govt, and I saw nuttier things in the military. The hulls themselves are often aluminum with AR500 or similar bolted on, so the difference in weight armored vs non seems right to my mind having seen 2.5 tons added to older HMMWVs with homemade "boonie" armor. I also wouldn't doubt that the appearance could be similar, esp to junior officers who aren't always the brightest or most experienced.
 
Just had a thought

Reactive armour involves loads of explosives.

Explosives get stored in a secured area or magazine.

Training tanks which spend Thier time on a range would need security or a pretty large building. In real life they are parked up in a Nissan hanger with a padlock keeping people out.

Transporting them about is a major pain in the bum either by self drive or low loader.

If there is no ammunition or explosives involved life is much easier for everyone.

I suspect they can make them combat fit relatively quickly.

 
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