Side by side ejection seat question
Stilton, it's down to what JTO said.
Regardless of whether you are single seat, side by side or tandem seated an ejection is a really violent event (it has to be, it's too gentle or "soft "you are possibly not going to escape in time) and passenger comfort is not really an issue, survival is all that counts, so a lot of what happens in and around an ejection is designed to be quite close to human tolerances and certainly on older seats you can expect at the very least to get smacked around, bruised, cut or worse, though I believe some newer seats (ACES) claim to be more user friendly.
As far as rocket packs and dual seating is concerned from memory on seats I sat on the gun (sometimes called a catapult) started things moving, the rocket pack fired when the seat is about 6 feet up the rails and it burnt for a very short time (AFAIK well under a second). Even if the two seats end up in close formation, with one in the rocket plume of the other, as in the F4 ejection I keep going on about, your protective equipment (fire resistant suit and under that in theory at least a roll neck shirt/and or a natty scarf, plus helmet, visor, gloves etc) should make the short exposure to the plume survivable in the vast majority of cases...you are not sat there wearing a t-shirt, shorts and a light weight headset.
Regardless of whether you are single seat, side by side or tandem seated an ejection is a really violent event (it has to be, it's too gentle or "soft "you are possibly not going to escape in time) and passenger comfort is not really an issue, survival is all that counts, so a lot of what happens in and around an ejection is designed to be quite close to human tolerances and certainly on older seats you can expect at the very least to get smacked around, bruised, cut or worse, though I believe some newer seats (ACES) claim to be more user friendly.
As far as rocket packs and dual seating is concerned from memory on seats I sat on the gun (sometimes called a catapult) started things moving, the rocket pack fired when the seat is about 6 feet up the rails and it burnt for a very short time (AFAIK well under a second). Even if the two seats end up in close formation, with one in the rocket plume of the other, as in the F4 ejection I keep going on about, your protective equipment (fire resistant suit and under that in theory at least a roll neck shirt/and or a natty scarf, plus helmet, visor, gloves etc) should make the short exposure to the plume survivable in the vast majority of cases...you are not sat there wearing a t-shirt, shorts and a light weight headset.
Last edited by wiggy; 13th Feb 2017 at 09:31.
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More info than anyone needs to know about 2 x side by side ejection seats in an S-3 Viking:
IE-1 escapac: escapac
FREE S-3B Viking NATOPS PDF (43.3Mb) http://air.felisnox.com/view.php?name=s3b.pdf
IE-1 escapac: escapac
FREE S-3B Viking NATOPS PDF (43.3Mb) http://air.felisnox.com/view.php?name=s3b.pdf
Last edited by SpazSinbad; 13th Feb 2017 at 09:49. Reason: add NATOPS info
From the training days; later seats MB Type 3 or 4 et al accelerate to 88fps (60Mph) in 0.2 sec. Bearing in mind human reactions etc, simultaneous ejection would be difficult to achieve unless thro' a Command Ejection system. Rocket packs achieve the divergence (sideways) by means of "handed" rocket pack venturis.......and remember, the occupant's chute should be opening after approx 2.25 secs (or less) after seat initiation.
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Some NANOsecondary from the S-3B NATOPS....
"...2.25.7.1 Command Ejection. When the command ejection (all crew) option is exercised, the two aft crew seats will eject 0.52 second(s) before the two forward crew seats. This time delay coupled with seat thrust trajectory assures separation between the four crew-members...."
&
"...2.25.3 Lateral Separation System. A system to maintain lateral separation during multicrew command ejection (crew eject) is provided by thrust from a small rocket thruster and the aerodynamic vane. As the seat separates from the aircraft, the aerodynamic vane [see below] is mechanically deployed into the airstream. The vane works in conjunction with the yaw thruster to rotate the seat into a trajectory that ensures lateral separation from the other seat trajectories. The lateral separation system provides a 60-foot distance between the seats during command ejection...."
&
"...2.25.3 Lateral Separation System. A system to maintain lateral separation during multicrew command ejection (crew eject) is provided by thrust from a small rocket thruster and the aerodynamic vane. As the seat separates from the aircraft, the aerodynamic vane [see below] is mechanically deployed into the airstream. The vane works in conjunction with the yaw thruster to rotate the seat into a trajectory that ensures lateral separation from the other seat trajectories. The lateral separation system provides a 60-foot distance between the seats during command ejection...."
Last edited by SpazSinbad; 13th Feb 2017 at 11:58.
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A bit of "flame". Ark Royal, November 1964, and pictures showing "Jane" and two experimental rocket assisted ejection seats. "As the float reached the end of the catapult the seats were fired, the dummies were ejected high into the air and then drifted gently down on their parachutes into the sea where they were rapidly recovered."
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Early missions flown by space shuttle Columbia had side-by-side ejection seats for the two man crews. The crew members had widely different views regarding these ejection seats.
Here's what STS-1 pilot Bob Crippen had to say: "In truth, if you had to use them while the solids were there, I don’t believe you’d—if you popped out and then went down through the fire trail that’s behind the solids, that you would have ever survived, or if you did, you wouldn't have a parachute, because it would have been burned up in the process. But by the time the solids had burned out, you were up to too high an altitude to use it. ... So I personally didn't feel that the ejection seats were really going to help us out if we really ran into a contingency."
And here's what STS-1 commander John Young had to say: https://youtu.be/JLU4CK7UHd4
Here's what STS-1 pilot Bob Crippen had to say: "In truth, if you had to use them while the solids were there, I don’t believe you’d—if you popped out and then went down through the fire trail that’s behind the solids, that you would have ever survived, or if you did, you wouldn't have a parachute, because it would have been burned up in the process. But by the time the solids had burned out, you were up to too high an altitude to use it. ... So I personally didn't feel that the ejection seats were really going to help us out if we really ran into a contingency."
And here's what STS-1 commander John Young had to say: https://youtu.be/JLU4CK7UHd4
Seems an odd thing to say as lots of things are bad 'if still there' when you eject. The engineers thought that pickling-off the solid boosters gave the crew a viable escape system; thoughts that were revisited several years later.
The F-4 had a sort of potential nasty where if the rear seater pulled the handle just before the front seater the rear seater would be going up the rails just as the front seat canopy ejected.... the rear seater would quite possibly "collect" the canopy with probably fatal results.
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In the documentary for the making of Top Gun, it is revealed that the scenario where Goose is lost is based on an actual loss of a RIO in an F14 that was in a flat spin ejecting up into the canopy.
The interesting point is that the scene had to be convincing, as well as throw no bad light on the Navy...
The interesting point is that the scene had to be convincing, as well as throw no bad light on the Navy...
Funny thing is that in a film full of unconvincing air combat scenes, I find the ejection scene the least convincing.
I'll have to recheck out the Top Gun scene when I've got better internet or I dig out the DVD but TBH I've never seen an ejection scene on TV or film that's been particularly convincing. As I mentioned earlier an ejection can be a really brutal event, and whilst others will no doubt have different opinions I think it's probably v difficult to recreate the sheer speed, violence and noise (especially at high speed ) associated with the real thing. Most dramatised scenes seem to show an unconvincing "pop" or "bang" and somebody being lofted out of the airframes as if by a strong spring ....it is not like that, most certainly not on a rocket seat...........
Last edited by wiggy; 18th Feb 2017 at 07:50.
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Submitted by: JRJarrell: Viking Lore and Stories
“Am sure you're aware, or its been pointed out, but the list of "fallen comrades" on the website in the History section is missing several who were lost in Vikings before 1980.
Very quickly, as I recall, the first casualty was an enlisted non-aircrew (and non-seat qualed) [?] plane captain who was riding in the back on a VS-41 ferry flight from NORIS to Burbank. The jet was scheduled to go to 22 and MCPO Harry Maddox of 22 was there waiting for it. And Harry climbed into the cockpit and shut down the jet after the mishap! Jim "Marv" Roy, as MO in 22 then, knows the story better.
My recollection is acft touched down fast and pilots ejected (LCDR Wally Ables and Lt Buck Johnson as I recall) thinking they had brake failure. They weren't injured, but, as only pax in the back, the other seat burned the p/c [plane captain passenger], seat, chute, et al.
Thus the soon to follow NATOPS change prohibiting only one backseater....”
Very quickly, as I recall, the first casualty was an enlisted non-aircrew (and non-seat qualed) [?] plane captain who was riding in the back on a VS-41 ferry flight from NORIS to Burbank. The jet was scheduled to go to 22 and MCPO Harry Maddox of 22 was there waiting for it. And Harry climbed into the cockpit and shut down the jet after the mishap! Jim "Marv" Roy, as MO in 22 then, knows the story better.
My recollection is acft touched down fast and pilots ejected (LCDR Wally Ables and Lt Buck Johnson as I recall) thinking they had brake failure. They weren't injured, but, as only pax in the back, the other seat burned the p/c [plane captain passenger], seat, chute, et al.
Thus the soon to follow NATOPS change prohibiting only one backseater....”
“The design requirement for the S-3 was to have a command escape system that would extract all four crew members from the airplane by activation of either the pilot or copilot ejection seats. The heart of this system was the four Escapac 1E-1 ejection seats. Each seat was tailored to its position, so that the trajectory of the seats would avoid colliding with other crew members or other ejection hardware. This image shows all four test dummies out of the cockpit during the sled test.” http://www.lockheedmartin.com/conten...8559510524.jpg
Last edited by SpazSinbad; 28th Feb 2017 at 22:03. Reason: add JPG
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Four-Crew, Sequenced Ejection System, Zero/Zero to 450 KIAS Ejection Capability [S-3 Viking]:
Code One: S-3 Viking Test Pilot Perspective · Lockheed Martin
"The design requirement for the S-3 was to have a command escape system that would extract all four crew members from the airplane by activation of either the pilot or copilot ejection seats.
The heart of this system was the four McDonnell Douglas Escapac 1E-1 ejection seats. Each seat was tailored to its position, so that the trajectory of the seats would avoid colliding with other crew members or other ejection hardware.
The seats were to work from zero airspeed, zero altitude up to 450 KCAS and all crewmembers were to be extracted in less than a second. The front two seats and the rear seats went out in pairs; the rear seats went out first, followed 0.5 second later by the front seats. The rear seats had a wider arc trajectory than the front seats for lateral separation purposes. All seats were designed to fire through the Plexiglas overhead canopy enclosures which is shattered by cutters on the top of the seats.
Development of the escape system took place first in the lab, but was tested with instrumented dummies on a rocket sled at NAS China Lake, California, in about twenty-four different combinations and airspeeds. All ejections at all speeds were successful the first time tested with no redesigns required.
In Service Successes and Failures: Several successful in-envelope ejections occurred from the S-3 over the years of service use. The only glitch was discovered inadvertently, when an ejection from an S-3A landing in Burbank for a factory mod resulted in a fatality.
It was discovered that all the tests had been conducted with both seats occupied, even with the extremes of weight in opposite seats, but no tests had been conducted with one seat empty next to a full seat.
The fatality was caused by a single point failure in the seat-man separation mechanism which prevented the seat to sequence. In addition, it was discovered that the deceased crew member had received severe burns from the rocket in the empty seat. From that point on, either both seats had to be occupied, or ballast was required in the unoccupied seat to avoid the possibility of rocket burns from the empty seat....”
The heart of this system was the four McDonnell Douglas Escapac 1E-1 ejection seats. Each seat was tailored to its position, so that the trajectory of the seats would avoid colliding with other crew members or other ejection hardware.
The seats were to work from zero airspeed, zero altitude up to 450 KCAS and all crewmembers were to be extracted in less than a second. The front two seats and the rear seats went out in pairs; the rear seats went out first, followed 0.5 second later by the front seats. The rear seats had a wider arc trajectory than the front seats for lateral separation purposes. All seats were designed to fire through the Plexiglas overhead canopy enclosures which is shattered by cutters on the top of the seats.
Development of the escape system took place first in the lab, but was tested with instrumented dummies on a rocket sled at NAS China Lake, California, in about twenty-four different combinations and airspeeds. All ejections at all speeds were successful the first time tested with no redesigns required.
In Service Successes and Failures: Several successful in-envelope ejections occurred from the S-3 over the years of service use. The only glitch was discovered inadvertently, when an ejection from an S-3A landing in Burbank for a factory mod resulted in a fatality.
It was discovered that all the tests had been conducted with both seats occupied, even with the extremes of weight in opposite seats, but no tests had been conducted with one seat empty next to a full seat.
The fatality was caused by a single point failure in the seat-man separation mechanism which prevented the seat to sequence. In addition, it was discovered that the deceased crew member had received severe burns from the rocket in the empty seat. From that point on, either both seats had to be occupied, or ballast was required in the unoccupied seat to avoid the possibility of rocket burns from the empty seat....”
Thread Starter
Very interesting, so the answer to my original question seems to be yes, the remaining
occupant in the cockpit after an ejection can be badly hurt or even killed if the system is not operated as planned.
occupant in the cockpit after an ejection can be badly hurt or even killed if the system is not operated as planned.