Nick,

Are you getting a sense of deja vu? Give it up, no one in their right mind reads this interminable drivel, you're only fanning the flames.

To: John Eacott

You obviously read it. If you think that what I post is drivel then if you never read anything else that I post please read and remember this:

“Let’s face the truth. The engineering and test departments at all of the aerospace companies never get it 100% right and the operational pilots are really test pilots until all of the bugs are removed and or corrected and in the process some of them get killed along with their passengers”.

LZ,

Nothing "obvious" about it. I can tell from the first two lines of your postings whether to scan on to the next, and that's generally what I find myself doing.

Your interminable bickering and meandering from the thread gives me the irrits. I'm sure that you could contribute much from your years in the industry, if only it could be put in a less agressive and, quite frankly, boring manner.

Heartily agree. How did we get here from a thread about ejection seats, anyway? . . <img src="confused.gif" border="0"> <img src="confused.gif" border="0">

[ 24 February 2002: Message edited by: heli ]</p>

Helicopter Ejection Seat Video
 

Can anyone point me at the old video showing an ejection seat trial, where the blades get blown off at their roots, and then the seat departs the aircraft?? Might have been Sikorsky, but not sure.

Thanks:ok:

I think it was a James Bond movie about 15 years ago.

Man, I'm not flying any helicopter that has something on board that can "blow the blades off at their roots".

Yeh, it upsets the passengers.

I think it was actually a Russian trial, not a U.S. Sikorsky one. They also had the idea of a sideways firing bang seat.

I don't know what to put in this space.
 

One of the first Cheyenne (AH-46) test birds had a downward firing ejection seat. it was located in the gunners position. The pilot would fly in the gunners position on certain flights in the event of a major failure. I believe the mechanism was taken from a B-47.

:E :E

I saw that trial on the Discovery Channel a while back, the programme was called Ultimate Machines, which was all bout choppers. I don't think it got past testing stage as it was too unreliable. :ooh:
DynamicallyUnstable is right, I wouldn't want to fly anything with those bolts either. I prefer my blades firmly attached to my rotor head!:ok: :ok:

Re: downward firing seats. Don't you have to be fairly high (helicopter terms) like 2k in order to succesfully use those? seems like the downwards one would be pretty useless. Not sure i would trust the side fire either. Guess thats why we dont see em in use then eh?

Thanks fellas, I realise that its a topic which is the source of much amusement, but I just recall seeing a video from on board the aircraft as it blew the blades and fired the seat, back in the 80's at the Royal Navy's Air Engineering School. It was just for interest value, you wouldn't get me in a contraption with exploding blade roots either.. I do have a few brain cells left;)

It has been on Discovery channel, and also I think it was on a 1-hour special called The Chopper. I used to show it to my students at night school to put them off helos.

The blades were fired off in sequence, then little rockets that spun like pinwheels pulled each crewmember out of the seat on a long cord and opened the parachute. Only demo'd with dummies borrowed from a Volvo commercial.

The Russians are still flying one. I first saw it at the Paris Airshow in 93 where they managed to initiate the first part of the ejection sequence during the pre-flight. All the blades came off but after some "words" with the aircrew and a durry, the mechs had them back on in about half an hour in time for the flying display.:ooh:

_________________________________--

The Ka-50 is the world's first operational helicopter with a rescue ejection system, which allows pilot to escape at all altitudes and speeds. The K-37-800 Rocket Assisted Ejection System is manufactured by the Zvezda Research and Production Enterprise Joint Stock Company in the Moscow Region. The seat operates by pulling the pilot from the helicopter cabin using a solid-propellant rocket motor. The system comprises the seat, a control unit and a pullout rocket motor. The seat is fitted with a survival pack containing an NAZ-7M survival kit, a life raft and a PS-37A parachute system. The seat provides safe forced emergency escape from helicopters in the speed range 0 to 350 km/hour and at altitude 0 to 6,000 metres. The seat also provides safe ejection during inverted flight (at speeds 0 to 330 km/h with zero vertical velocity) at a minimum altitude of 90 metres.

Helicopter ejector seats
 

This is actually a serious question, so no jokes:D .
I was watching discovery last night, it was a doco on ejector seats. THey were covering different systems, when all of a sudden they start talking about helicopter systems.
I know the russian Ka-50 has a zero-zero style seat, which as far as I know is the only operational one in a helo.
But hte one they were showing on this program looked like a S-62 fuse, on a track complete with rotating blades. The blades were all fired off, one at a time, the the crew were ejected out.
Heres the strangest bit though, instead of rockets under the seats, they were pulled out of the cabin via 4 or 5 rockets spinning, connected to the crew by a cable.
Maybe they though helo pilots would only accept rotating propulsion?
If any one knows about this program, I would appreciate any info.

I didn't see the program, so I can't say what was shown, but the part about ejecting the blades one at a time sounds fishy. As soon as one blade is gone, the imbalance is so bad that the entire transmission generally exits, within a fraction of a second. To work, all the blades need to exit at the same time.

There has been some sporadic work on helicopter ejection seats over the years, but AFAIK no functional system has been fielded. The problem of the blades is not trivial, and the only alternative is to fire the seats out the bottom, which is also not optimal.

Personally, I would prefer to ride down inside the helicopter than an exploding seat and parachute that might or might not work, and I say that as a former paratrooper and current helicopter pilot.

I asked the same question a few weeks back, glad I'm not actually losing my marbles!!

When I was at the Navy's Air Engineering school I saw probably the same clip you refer to. The blades were all blown off (Don't remember them going sequentially, but wouldn't argue) and the crew exited vertically, and successfully. The other one I saw was a sideways firing seat.. now that looked iffy!!!

As far as I am aware, no assisted escape system actually exists in service in the west. I don't subscribe to the the "autorotation or doom" philosophy. I think any poler in a situation of extreme peril (Deep sh!t as we commoners say!!) would welcome a last ditch method of potential escape, if he was being honest.;)

That footage dates back to pre-87, and the blades were fired off two at a time, from opposite sides of the mast, but in a fraction of a second.

The pilots were pulled out through the overhead window (also blown out) by their harness using a rotating rocket system.

never put into production.

Can you imagine some dopey passenger saying "What does this button BOOM! BOOM! Phhhhiizzzzzz!......... ooops.."

Helo seats have to be different from aeroplane seats as they need to absorb vertical accelerations - plank seats take mostly forward forces. So there is no room under a helo seat for an ejection system, and they are heavy and require huge amounts of maintenance. Specialist cracker people. Parachute people, plus pulling the rotten things out at regular intervals and testing and repacking them. Big costs.

And as far as i know, civil aircraft aren't permitted to have active ejection seats. When the old warbirds fly, the pilot knows he has to ride it in. Many have done so.

And anyway, how do you also eject 12 or 14 pax down the back? And an S76 doesn't even have an overhead window!

AC, in the U.K there are alot of warbirds with "live" seats. Brings all sorts of issues about servicability and time expired parts especially with eastern bloc machines.

Reminds me of possibly the only funny thing that the "commedian" Jim Davidson said. He was having a flight in a military helicopter and he asked why it wasn't fitted with an ejector seat. The "other rank" pointed at the rotors and said "If they tried that they would get Officer burgers, they are like beef burgers only thicker!"
Oh and some ex military jets do fly with armed ejector seats.
Rgds Dr.I.

How to avoid officer burgers.
 

One of the Cheyenne test birds had a downward firing ejector seat in the gunners position. During some tests the pilot operated the helicopter from the front seat. The seat I believe was taken from an Air Force B-47

:E :E

Why couldn't there be a system that ejected the blades and then deployed a small parachute from the top of the helicopter? This smaller chute would assure that the craft remained upright and that the vertical speed at ground contact was within the limitations of the seats.

AC

Here's the gen on civvy ejection seats:

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

or

http://www.ejectorseats.co.uk/rules.html

Hope this helps?

JG

Dave, I was thinking the same thing as you. I just looked at the oh-58 and thought why not replace the bulky observation equipment with a smaller parachute?

I've been wondering about this also - the Cirrus has a parachute that can bring the a/c safely to earth in a catastrophic failure situation, why not for helicopters?

I know I'd love something like that if for whatever reason I found myself in "stone" configuration. Seems like a no-brainer for the manufacturers to come up with.

Imagine what it would do to insurance premiums! Surely this is a Good Thing (TM)?

--
Michael.

The concept of parachutes for helicopters was previously discussed here (click link). Personally, I put my hat in the "don't want a parachute on my helicopter" camp. I think you create too many single points of failure with such a complicated system, and it may create more problems than it is worth. Also, there would be an enormous expense in terms of development, testing, certification, and implementation (not to mention weight and performance penalties). Autorotations, autorotations, autorotations, autorotations, autorotations... the more your practice, the better your chances are. In my opinion, it is an unreasonable expectation to eliminate every risk factor by dumping more systems that require more maintenance with smaller margins for error.

Alternatives
 

OK. Forget the parachute. :)

How about producing stronger blades and rotor hubs etc. from some of the weight savings that result from the new lightweight materials?

And/Or, a rotor governor that would only start lowering blade pitch if sensors detected any extreme loading on the rotor, which was causing a component to approch its ultimate strength.

When I said "stone" configuration, I meant exactly that - catastrophic failure of the rotor system in some way that makes autorotation an impossibility. I believe a parachute would cause far more damage on landing than a well-executed autorotation, but if it slows the machine down enough for the occupants to survive the landing, then it sounds good to me.

--
Michael.