Energy Attenuating Seats

[and Tompkins]

Can a Bell 412EP, Sikorsky S-76C+, or Eurocopter EC155B1 be purchased (or equipped with little/no modification) with energy attenuating seats? A quick search of the internet left me to believe that the only options currently available are for crew seats only.

If not in current models, what about in future models like the S-76C++, S-76D or an upgraded EC155?

Thanks!

[PANews]

I am not sure about all of your list, but the answer is yes as far as the 155 is concerned. Although the basic airframe can call on Grandfather rights to avoid the issue I am sure that all the passenger examples I have studied have 'stroking' seats fitted.

That does not necessarily mean that all the airframe components are crashworthy to JAR/FAR 29 standards though..

[Blackhawk9]

Yes , Attenuating seats (stroking) are available for the EP, so I assume you could retrofit back to HP,SP,Classic or you can go with aftermarket seats but big$$$

[Geoffersincornwall]

The S76 range (incl the new 'D') will continue to feature the fuel tank under the rear row of passenger seats so no hope of a full complement of attenuating seats here I'm afraid

G

:(

[Von Smallhousen]

Try Aerospace Technology Ltd, they have a range of both medical and crew seats that are adjustable and energy-Absorbing

www.tslaerospace.com/product/simula/sim001ea.htm

[Oogle]

I had to research this one once:

Look at Simula or Martin Baker energy attenuating crew seats. Very well constructed.

Around US$5000 - $6000 for each seat and then certification into your aircraft would be on top of that.

The beauty of them is that they do not require floor space. They are mounted on the walls of the aircraft and can be flipped up out of the way when not being used. A good idea for winching operations where the crewman can sit on the seat in the doorway then when it comes to conducting the winch, he can flip it out of the way. Especially good for stretcher winches where door space is at a premium. 4 point harnesses as well.

And NO - I don't work for them

[and Tompkins]

The 412EP and 155B1 would only be for retrofit only? Am I understanding correctly?

Thanks again for all the responses!

[NickLappos]

Unfortunately, scanning the seat manufacturer's sites can be disappointing, because those seats have to be designed into the primary structure of the helo. That being said, those side-mounted stroking seats are very nice, indeed. The S-92 uses them (the Martin-Baker ones). It isn't a bed of roses mounting them, however, because the loads they impose on the sidewall require pretty strong wall frames. It is unlikely that a wall not designed for these loads can have the seats fitted.

For the same reason, even regular floor mounted seats that absorb crash loads require a much stronger floor structure than was previously the norm. It is unlikely that such seats would be a bolt-in job for older helos.

Geoffersincornwall is right, the rear seats on the S-76 cannot accomodate any stroke. There are crew seats that are energy absorbant, however.

[Genghis the Engineer]

An aside, I've done quite a lot of work on energy attenuating seats for light aircraft. Sometimes budgets and practicality just don't allow you to fit such a thing.

There's a fellow here in the UK called Dr. Tony Segal who has done a great deal of research on the subject, particularly in gliders. He ended up (amongst other things) developing a rather peculiar "conformal" foam foam for glider seats - I've seen the research and appropriate use of the stuff within a seat (in place of normal foam cushions, not as-well) has a remarkable attenuating effect on energy transmission from airframe to pilot-frame in the event of a crash. To modify a seat you are looking at a few hundred US$ - the most knowledgeable supplier being "RD Aviation" which is part of "Airplan Flight Equipment" or AFE.

Clearly not as good as a proper energy attenuating seat, but a remarkably good second best. VP959, one of our occasionals here managed a couple of years ago to crash a light aircraft in which I'd mandated use of Tony Segal's "Dynafoam" - he's still fit as a fiddle, the aeroplane took about a year to rebuild including replacement of most of the fuselage structure.

Here (http://www.afeonline.com/afeshop/index.html?lang=en-uk&target=d142.html#p329) is a link to some "off the shelf" seat cushions with a description of the stuff - although clearly an off the shelf cushion is a bit of a gash solution and it's rather more sensible to design it into the seat overall. If you want TS's contact details PM me, in my experience he is always delighted to provide any amount of technical advice - basically it's his life's work and he wants everybody to know about it (and I've never seen him ask money for anything, he's a retired medical Doctor using his professional skills to excellent effect).

G