ArmitageShanks
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Logic Behind Ejection?

Tue Nov 20, 2007 7:51 am

That V-22 thread made me interseted in how ejection seates are chosen on certain aircraft.

Does the military have a policy that ejection seats will only be installed when all crew will be able to escape?
 
KELPkid
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 7:57 am

Is there really any logic to strapping a seat onto what is normally an artillery shell? Big grin (The rocket motor is usually the propellant section from an artillery shell...).
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Starlionblue
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 8:16 am



Quoting ArmitageShanks (Thread starter):
Does the military have a policy that ejection seats will only be installed when all crew will be able to escape?

Unlike the notorious Vulcan then.  Wink
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oldtimer
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 1:41 pm

Quoting Starlionblue
Unlike the notorious Vulcan then

Other military types like the Victor and Valiant and others had limited number of ejection seats fitted. It was impossible to fit all crew members with them in the confined enviroment of these designs. The hope was there would always be time for the crew to evacuate before the pilots "banged out" In fact if you look at the accident rate of these aircraft, the Vulcan had more all out survivors than the others.
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Jetlagged
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 2:48 pm

Many military aircraft do not have ejection seats (tankers, transports, etc). Ejection seats are primarily designed for escape from fast jets, where traditional methods are virtually impossible. It's much harder to arrange in helicopters, and ejection from the V-22 while the rotors were tilted would be equally problematic. So it's not just a matter of the pilot's not getting the seats because the passengers don't have them.

The Vulcan crews with no ejection seats had an assisted escape mechanism, but from what I've read this was more lethal than simply jumping out of the hatch.
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CosmicCruiser
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 3:38 pm

checkout the escape hatch in the floor of the Concorde that is at Duxford. It was ser. 2 I believe and used for certification tests and therefore had a means of escape if it all went wrong. Even the docent in the cabin said you'd probably be smashed.

 
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 3:38 pm



Quoting Starlionblue (Reply 2):
Unlike the notorious Vulcan then.

How about he B-52? Did the tail gunner have an ejection seat? I know that that position has been recently decommissioned...

Quoting Jetlagged (Reply 4):
It's much harder to arrange in helicopters, and ejection from the V-22 while the rotors were tilted would be equally problematic.

IIRC, most helicopters with ejection systems eject the flight crew downwards (Apache comes to mind...). Obviously, if the Osprey is being used as a troop transport, even if the flight crew punches out, that still leaves quite a few on their own to find a way out...wouldn't want to be the loadmaster on a doomed Osprey after the flight crew has bailed out  Sad
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CosmicCruiser
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 3:50 pm

I'll try it one more time, I don't know what happened.

 
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Moose135
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 6:07 pm



Quoting KELPkid (Reply 6):
How about he B-52? Did the tail gunner have an ejection seat? I know that that position has been recently decommissioned...

In the D-model, when the gunner sat in the tail, he would jettison the gun turret and bail out the opening. In the G- and H-models, the gunner sat up front with the rest of the crew (guns were controlled remotely) and had a normal ejection seat. The gunner position was eliminated in 1991. In the B-52, the Navigator and Radar Nav (bombardier) ejected out the bottom, the rest out the top. Anyone who did not have an ejection seat (they could carry several additional crewmembers) went out the opening after the Nav ejected.

I've flown ejection-seat aircraft, and while I never needed to use one (although I did consider it a time or two) I do know other pilots who did, and were glad to have one when they needed it. I also flew the KC-135, without ejection seats. We had parachutes in the back of the airplane (at least on the alert birds, maybe all the time, it's been a while) but unless it was a controlled situation, no one expected to successfully bail out of a tanker.
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FredT
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 6:12 pm



Quoting KELPkid (Reply 6):
IIRC, most helicopters with ejection systems eject the flight crew downwards (Apache comes to mind...)

Ehm... ejection seat in the Apache? Now, that's news...
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Jetlagged
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 7:26 pm

Downward ejection in a low flying helicopter sounds like an attractive prospect.  Wink I suppose it would end your troubles just a bit quicker.

I vaguely recall a prototype helicopter escape system which involved jettisoning the main rotor blades first, followed by upward ejection. Might be unpleasant for another helo in close formation....
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Viscount724
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 9:18 pm



Quoting CosmicCruiser (Reply 5):
checkout the escape hatch in the floor of the Concorde that is at Duxford. It was ser. 2 I believe and used for certification tests and therefore had a means of escape if it all went wrong.

The first A380 also has an emergency crew escape hatch behind the cockpit that exits out a hatch in the forward cargo door. It's shown in a video on A380 development. It shows the crew (wearing parachutes) boarding the aircraft for it's maiden flight and one of them points out the escape hatch in the floor. You can see where it exits in the photo below (red outline).


View Large View Medium
Click here for bigger photo!

Photo © French Frogs Aviation Pictures



Relevant excerpt from another forum:

As others have said, here is an escape hatch fitted into the R1 cargo hatch on MSN001 that is activated by that panel in the cockpit. The retaining lock is removed prior to flight and put back into place when the aircraft is made safe, because the escape hatch is permanently armed. In the event of an inflight emergency, the pilots would blow this hatch and the flight test crew would evacuate through this hatch via a slide positioned just behind the flight deck. This is standard procedure on all flights in the first stages of a flight test programme, and Boeing did indeed do it on the 777 - in the documentary 'Building a 21st century jet' where they cover the first flight, you can see the crew all wearing parachutes.
 
EMBQA
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 9:25 pm



Quoting KELPkid (Reply 6):
How about he B-52? Did the tail gunner have an ejection seat? I know that that position has been recently decommissioned...

I would really not call over 25 years ago 'recent'

Quoting KELPkid (Reply 6):
most helicopters with ejection systems eject the flight crew downwards

I can't think of one modern helicopter that has an ejection seat. None at least in the US Military
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FredT
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 10:23 pm



Quoting EMBQA (Reply 12):
I can't think of one modern helicopter that has an ejection seat.

I think it is the Ka-50 which has an ejection system. Don't quote me on it, but I think it blows the main rotor off prior to ejection.

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Moose135
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RE: Logic Behind Ejection?

Tue Nov 20, 2007 10:53 pm



Quoting FredT (Reply 13):
I think it is the Ka-50 which has an ejection system. Don't quote me on it, but I think it blows the main rotor off prior to ejection.

You are correct - from fas.com, http://www.fas.org/man/dod-101/sys/ac/row/ka-50.htm

Quote:
"The Zvezda K-37-800 pilot ejection system functions at any altitude, and enables a successful ejection at low altitude and maximum speed."

Also read on Wiki that the rotors are blown off the rotor disk.
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dragon6172
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 12:54 am

Ks-50 is the only helo I know of that ejects. And honestly I have always thought, that flying around with charges that are capable of blowing my blades off was not something I wanted to experience. What if you lose a blade because of a stray 'tron? Or what if not all of the blades blows off when you try and eject? The way I understand, the system was set up to not let the seat go until all the blades were gone (keeps you from being chop suey). So now if one blade doesnt blow... now you are in a really uncontrollable situation... where as if you had kept all your blades and rode an auto-rotation in, you would keep some control!!

Quoting KELPkid (Reply 6):
IIRC, most helicopters with ejection systems eject the flight crew downwards (Apache comes to mind...).

Uh...???
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Starlionblue
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 1:34 am



Quoting FredT (Reply 13):

Quoting EMBQA (Reply 12):
I can't think of one modern helicopter that has an ejection seat.

I think it is the Ka-50 which has an ejection system. Don't quote me on it, but I think it blows the main rotor off prior to ejection.

Indeed.

Quoting Dragon6172 (Reply 15):
Ks-50 is the only helo I know of that ejects. And honestly I have always thought, that flying around with charges that are capable of blowing my blades off was not something I wanted to experience. What if you lose a blade because of a stray 'tron? Or what if not all of the blades blows off when you try and eject? The way I understand, the system was set up to not let the seat go until all the blades were gone (keeps you from being chop suey). So now if one blade doesnt blow... now you are in a really uncontrollable situation... where as if you had kept all your blades and rode an auto-rotation in, you would keep some control!!

Better some chance than none at all.
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57AZ
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 4:24 am



Quoting Jetlagged (Reply 4):
Ejection seats are primarily designed for escape from fast jets, where traditional methods are virtually impossible.

IIRC, the chief issue is ensuring that the pilots are able to exit the aircraft in such a manner as to avoid hitting a part of the airframe. With the early fighter jets, the immediate issue was clearing the horizontal and vertical tail fins. As pointed out in the A380 thread, even the prototype airliners are equipped with an escape mechanism. On the MD-80/90 series jetliners, the prototypes used for flight testing had a slide that led to the detachable tail cone. The idea was that if the airplane were to get into a high altitude stall or spin that could not be recovered from, there was a chance that the crew would be able to make it to the rear of the aircraft and bail out through the tail cone.
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KELPkid
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 4:44 am



Quoting FredT (Reply 9):
Ehm... ejection seat in the Apache? Now, that's news...



Quoting EMBQA (Reply 12):
I can't think of one modern helicopter that has an ejection seat. None at least in the US Military



Quoting Dragon6172 (Reply 15):
Uh...???


 white  Okay, Okay, I don't know why I thought the Apache had an ejection system  footinmouth 
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KELPkid
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 4:48 am



Quoting EMBQA (Reply 12):
I would really not call over 25 years ago 'recent'

To which I will add:

Quoting Moose135 (Reply 8):
The gunner position was eliminated in 1991.

Since you can't do math, I'll do it for you. 2007-1991=16.

And I'll have you know, when I was in AFROTC in college, one of our detachment's sargents had just come off of a tailgunner assignment...
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dragon6172
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 5:52 am



Quoting KELPkid (Reply 19):


Quoting EMBQA (Reply 12):
I would really not call over 25 years ago 'recent'

To which I will add:

Quoting Moose135 (Reply 8):
The gunner position was eliminated in 1991.

Since you can't do math, I'll do it for you. 2007-1991=16.

And I'll have you know, when I was in AFROTC in college, one of our detachment's sargents had just come off of a tailgunner assignment...

The B-52G was the first model that moved the tail gunner to the front of the plane, they were all built in the 60s. So I would say thats more than 25 years ago. I think that is what he meant. And according the Air Force Museum web site...

In October of 1991, the gunner's station was removed as an economy measure, reducing the crew complement to only five. The gunner's ejector seat was, however, retained, and can now be occupied by an instructor or flight examiner who often goes along on training missions. The M61A1 Vulcan 20-mm cannon in the tail was taken out during 1991-94 and the gun opening was covered over by a perforated plate, although the wiring and instruments associated with the gun were all retained so that the gun could in principle be reinstalled, although there are no longer any gunners available to operate it.
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redflyer
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RE: Logic Behind Ejection?

Wed Nov 21, 2007 4:38 pm



Quoting 57AZ (Reply 17):
On the MD-80/90 series jetliners, the prototypes used for flight testing had a slide that led to the detachable tail cone. The idea was that if the airplane were to get into a high altitude stall or spin that could not be recovered from, there was a chance that the crew would be able to make it to the rear of the aircraft and bail out through the tail cone.

While I'm sure the tail cone egress was an option, I find it hard to believe anyone would consider using it in a high-altitude spin. That would mean the flight crew would have to get out of their seats and crawl roughly 100 feet to the back all while struggling against the forces created by an uncontrolled airplane.
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