Ejector seats

[Spikey]

Pardon my ignorance, but in privately-owned vintage jets such as the Hunter that went in at Shoreham, is the bang seat normally in working order?

[Dave Hopkin]

No they are normally deactivated - Ejector seats utilise exposives and rockets to function and few civilian operators have the required licencing to handle explosives

[Spikey]

Cheers Dave. It was the explosives aspect I couldn't see being feasible.

[Tony F]

http://www.ejectorseats.co.uk/seat-regs.html

Can't link that on my phone so copy and paste it on your pc. This is something I always wondered ? If they get serviced by Martin baker then surely they are usable?

Tony

[Dave Hopkin]

Posted by Tony F on 24/08/2015 07:31:30:
http://www.ejectorseats.co.uk/seat-regs.html

Can't link that on my phone so copy and paste it on your pc. This is something I always wondered ? If they get serviced by Martin baker then surely they are usable?

Tony

There is no CAA regulation about Ejector Seats, it seems to be dealt with on a case by case basis, the reason why most do get deactivated is that the cartridges that initiate the sequence have to be regularly replaced, which means the roiutine maintenace organisation is required to have a firearms/explosives licence, these are available BUT the hoops they have to jump through means many organisations deem it too much trouble and simply have the seats deactivated

I am not sure where the author of that sire gets his data from but his comment about being unlikely to get a airworthyness cert without them does not seem to be bourne out by the number of ex-military jets flying round without them

[Mowerman]

The companies that operate these ex-military jets are professional and I am sure hold the required explosive permits. Not only the ejection seats use cartridges, canopy jettison, emergency undercarriage and fire extinguisher systems are often cartridge operated.

[Tony F]

Hi Dave CAA have a pdf file here = **LINK**

And Chapter 5 makes interesting reading.

5.8 Where ejection seats are an integral part of the aircrew escape system, as specified in the relevant Pilots Notes, Flight or Aircrew Manuals, it is recommended that they be fully serviceable for all flights. Approval should be sought from the CAA (Application and Approvals) at the earliest opportunity if it is intended to operate with inert ejection seats (or other escape systems). It is unlikely that the CAA will allow swept-wing aircraft fitted with ejection seats to be flown unless the equipment is fully operational.

5.9 Ejection seat cartridge lives are typically 2 years installed, within a 6 year shelf life. To be fully serviceable the cartridges installed must be within their appropriate lives.

Tony

[Jon H]

given the fact that the pilot could see the point of impact and the bystanders who would be hurt i would imagine he tried to recover the aircraft to prevent the accident. Had he been over the sea or over trees he may have ejected. Without all the facts its hard to made a judgement

[Dave Hopkin]

Posted by Jon Harper on 24/08/2015 09:13:43:

given the fact that the pilot could see the point of impact and the bystanders who would be hurt i would imagine he tried to recover the aircraft to prevent the accident. Had he been over the sea or over trees he may have ejected. Without all the facts its hard to made a judgement

I have no doubt that the Shoreham Hunter Pilot stayed with the aircraft rather in an attempt to minimise the disaster - with or without a bang seat - a brave man

[Tony F]

Posted by Dave Hopkin on 24/08/2015 09:22:42:

Posted by Jon Harper on 24/08/2015 09:13:43:

given the fact that the pilot could see the point of impact and the bystanders who would be hurt i would imagine he tried to recover the aircraft to prevent the accident. Had he been over the sea or over trees he may have ejected. Without all the facts its hard to made a judgement

I have no doubt that the Shoreham Hunter Pilot stayed with the aircraft rather in an attempt to minimise the disaster - with or without a bang seat - a brave man

Wholeheartedly Agree Dave.

[Dane Crosby]

The bang seats fitted to the Hunter are an old type similar to the seats I sat in on the JP5. They are not of the "zero/zero" type. They would only work correctly when used above 90kt, and, at a height of over 90 feet or greater than 10% of your RoD. A lot to think about when things start to go wrong.

I wish to add my condolences to families and friends of the deceased from this accident.

The CAA are revisiting the rules for display organisation and I hope they find a way for displays to continue showing our great aviation heritage. If manoeuvres, min heights, display lines and safety zones need to be tamed then so be it but I would like to see all airworthy vintage aircraft keep flying where safe and possible.

[Spikey]

Posted by Dane Crosby on 24/08/2015 10:13:07:

The bang seats fitted to the Hunter are an old type similar to the seats I sat in on the JP5

Oooooh ... JP5, eh? I never even got to the JP4

Just for the record, my question was a general one, only prompted by Shoreham in so far as my wife asked why he didn't eject, and my explanation got me wondering about moving furniture in civilian-owned aircraft generally.

Posted by Tony F on 24/08/2015 09:10:33:

5.9 Ejection seat cartridge lives are typically 2 years installed, within a 6 year shelf life. To be fully serviceable the cartridges installed must be within their appropriate lives.

Thanks for posting that link, Tony.  Very interesting.  So if the fireworks are good for two years installed, how often does the 'chute need taking out and re-packing?

Edited By Spikey on 24/08/2015 13:02:32

[John Privett]

The Mk5 JP I had a.flight in some years ago had deactivated seats and my understanding at that time was that that was the norm - maybe only for JPs though? Certainly current CAA documentation as above makes it clear that for swept wing aircraft originally fitted with bang seats it is expected that they would be.retained and a strong case would need to be made for their deactivation to be approved.

[Nigel Dell]

XH568 the ex Bedford Canberra had to have working ejector seats and I think you will find that the starting systems was also explosive based as were many of the Royal Navy Hunters IIRC the maintenance company holds the necessary licences or at least the engineers we used did.

They also have to be stored correctly for obvious reasons which is why we used a recognised maintence company as they had the facilities.

Edited By Nigel Dell on 24/08/2015 14:06:08

[Peter Jenkins]

The other pyrotecnic that is on the aircraft is the ERU or explosive release unit. That's used to blow off the drop tanks. There were also EMRUs - electromagnetic release units but I can't remember what the fit on the T7 was. All the Mk 6A and Mk 9 Hunters I had under my charge had ERUs on the inboard pylons as they had 230 gallon drop tanks whereas the Mk6 and T7 had 100 gallon drops and may have had EMRUs. An armourer would know.

[Area 51]

It'll probably be tied to the maintenance scheduled agreed for the type on its permit to fly with the CAA; and for the issue of the CofA, thereafter the pilot rating.

[Vecchio Austriaco]

Pyrotechnic articles are not only in planes - look at your cars - if you are not driving a real historic vehicle you will have 1 or more airbags, and probably seat belt pre-tensioners. The latter are there since years - and not only in supercars. How do I know? - well I crashed my 6-year old Vectra in 2001 and it had already seat belt pre-tensioners....They are all activated by pyrotechnics. Of course the load will be higher to get a seat out of a crashing plane, but the technology and safety will be quite similar I suppose. And I think the number of erratic exploded air-bags or pre-tensioned belts is pretty limited.
VA

[fly-navy]

Navy Hunters had ERU's for the drop tanks, the ejection seats had three seat cartridges, main one which started the lifting sequence then two intermediate cartridges which where fired individually at the progression of the telescopic seat guides, this system was to facilitate a steady smooth journey out of the a/c, these int. cartridges were fired by the hot gasses of the main cartridge which was detonated by sprung loaded firing pin which was activated by pulling the face/seat handle which in turn removed the sear holding the pin spring in compression, as was said earlier though, it did not have the zero/zero capability, I suppose in a different situation to the Shoreham one though I would chance it.

Other cartridge on those seats is the drogue gun cartridge which fire a small stabalizing parachute to steady the seat .

nasty buggers these, the projectile which comes out of the gun would go through a railway sleeper from 10'. One of these went though a guys head at Lossiemouth and he lived.