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OV-1 Mohawk ejection seat

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I have seen that ejection seats have been drawing some interest so I thought I would exhibit one of two MkJ5B ejection seats that I own, although this one has a prospective buyer I am just waiting to hear from about delivery. This seat has been sitting in storage for six or seven years as I have not gotten around to breaking it down, cleaning it up and putting all the 100% correct parts on it. As is it's just thrown together to keep the parts in one place. The other seat is 100% finished and I'll see about photos of it later.

 

IH

Front view

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Awesome seat. I finally got the pubs on this and the parachute system used with it as well as the training handout from 1968. Never got the RJEs for it huh. Interesting how the Army modified it with the Koch's like it was a intermediate between the B and D seats. I have seen early RJE fitting harnesses for the A and B seats modified with the Koch fittings in the past.


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Some serious hardware! :w00t:


"We shall defend our island, whatever the cost may be. We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender!"

 

Winston Churchill

" Life is what happens to you when you're busy making other plans."

John Winston Lennon

 

 

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That is one good looking seat that would look great in a war room. What would something like this cost and where could Someone find one?


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That is one good looking seat that would look great in a war room. What would something like this cost and where could Someone find one?

 

This one is for sale, $900.00. I have a buyer who I am waiting on for delivery details. The second one I have would be significantly more because it is 100% correct restored. Finding these became extremely difficult after the DOD halted sales of them as "scrap". Now it appears they are having the rails cut leaving only bucket intact. There are other places like Ebay that have old released seats that people got before the demil order. They range from $400.00 to $4,000.00. There is even a very rare low serial number seat being sold in the UK that he is asking $244,000.00 for. He claims it's a historic, collector seat. Could be, I don't collect seats.

 

IH

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Awesome seat. I finally got the pubs on this and the parachute system used with it as well as the training handout from 1968. Never got the RJEs for it huh. Interesting how the Army modified it with the Koch's like it was a intermediate between the B and D seats. I have seen early RJE fitting harnesses for the A and B seats modified with the Koch fittings in the past.

 

The parachute pack is the same as the F-8 Crusader early seat. Somewhere in the history documents of the 131st and 225th Mohawk Companies I came across note that the Navy ALSE at DaNang helped these units because of shortages. By using a harness with Koch fittings the parachutes in the inventory at the Navy facility could be used in the Mohawk. There was also some use of Navy harness's because of shortages. I have what appears to be one of these "mis-matched" harness's that I acquired with this seat. It has RJE fitting for the seat kit, the same as the early F-8 seat. I believe it was referred to as the MkF5. The F5 had the RJE fitting swapped for Koch fittings because of user friendliness and lack of support for the fittings that would break. The F5 was replaced with an upgrade called the F7. This seat used the exact same parachute set up as the F-4 which eased inventory constraints.

 

IH

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This is my fully restored MkJ5B seat. The parachute is packed and the drogue chute is packed. The seat raise mechanism works. The leg restraints have the white and blue garters attached. It has the number 883 painted on the back plate under the parachute which comes back to an OV-1C, 66-18883. This airframe was scrapped in 1972. Considering the seat was rough when I got it and it came from Arizona it seems likely it came from that airframe. Only way to prove it for sure would be to find maintenance records that show that serial numbered seat being installed in that airframe. I'm not that keen to go that far.

 

IH

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Nice OV-1 seats! The seat-survival kit/cushion assy. looks similar to the A-6A Intruder GRU-5 ejection seat that I had at one time. It is interesting to learn that some

of the OV-1 pilots were using the USN/USMC torso parachute harnesses. Were they the standard MA-2 or the MA-2P? I will let you know if I find a list of service

assignments for your OV-1 seat. Did the early OV-1 seats use a rigid upper ejection handle that came to a point in the front instead of the later flexible one? The

following sources may help with restoration:

 

flighthelmet.com

bellsaviation.com

magnum-aero.com

paragear.com

ebay.com

barnstormers.com

parapub.com The Parachute Manual book by Dan Poynter.

ejectionsite.com

seatejectcolor.com

ejection-history.org.uk

United States Combat Aircrew Survival Equipment book by Michael S. Breuninger.

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Nice OV-1 seats! The seat-survival kit/cushion assy. looks similar to the A-6A Intruder GRU-5 ejection seat that I had at one time. It is interesting to learn that some

of the OV-1 pilots were using the USN/USMC torso parachute harnesses. Were they the standard MA-2 or the MA-2P? I will let you know if I find a list of service

assignments for your OV-1 seat. Did the early OV-1 seats use a rigid upper ejection handle that came to a point in the front instead of the later flexible one?

 

I don't know the nomenclature of the harness they were using. The one I have does not have any tags on it and the blue ink markings are faded to the point of being unreadable. The MkJ5B seat all used the flexible U shaped handle. The rigid handle you mention was made to be used on the MkJ5D seats that were installed into the OV-1D. These seats were modified by contractors for the US Army as Martin Baker refuted the Army claims of instability and near collisions with the tailfins due to the trajectory of the seat. The Army modifications included a better seat kit with thigh pads, a different rigid parachute container, new positive grip firing handles and an under seat tip-off compensator rocket. This helped boost the seat in a stable arc well over the tailfins eliminating the concern of a strike.

The owner of flighthelmet.com is the prospective buyer of the first, unrestored seat I have pictured.

 

IH

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It is interesting to learn that some
of the OV-1 pilots were using the USN/USMC torso parachute harnesses. Were they the standard MA-2 or the MA-2P?



My early AO-1A, B and C operators manual (pre OV-1 designation) shows that either the very early Navy MA-2s could be used or the Air Force style quick fit harnesses. When I say the early MA-2, these were the full body type, had the long zippered REDAR hose cover, upper and lower RJE fittings and also had vertical restraint straps that attached to the old style lap belts as this seat has. I will try and take a pic of the page from the -10 that shows the MA-2 and post it later.

Here is a pic of the my OV-1 quick fit harness as setup in the fully restored seat with the RJE fittings on the risers:
post-5589-0-48927700-1406839533.jpg

The brown straps are the vertical restraint straps. The metal tabs on them fit around the female side of the seats lap belt, and a small survival kit retention lanyard on the lap belt also clips to the left hand metal tab. The early MA-2 harness had these straps from what the pic in the -10 shows.

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Took some quick pics:

 

This is from the 1962 dated AO-1 (OV-1) operators manual.

1.jpg

2.jpg

 

Then some seat pubs:

 

5.jpg

 

3.jpg

 

4.jpg


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The harness you show could be used with the restored seat but it doesn't look like it has the lower RJE fitting, it would require the chest straps to help retain the seat kit. The quick fit harness shown in the -10 or one like it with fittings arrangement would work with it. Your book shows two harness's, the MA-2 torso would not work as it does not appear to have the lower RJE fittings or chest straps. You can see one of the lower RJE fittings on the left thigh support of the restored seat. They are attached directly to the seat kit with a nylon strap. The Quick Fit harness has RJE fittings both at the shoulder and at the waist, and no chest straps. Both of the seats have the RJE fittings at the waist/leg position. A "mish/mish" harness like the one I have would allow for a "borrowed" Navy parachute to be used with a MkJ5B seat. Altogether, these things evolved through different variations which would normally be accounted for by appending the appropriate manuals with T.O. changes. Through use, certain features always turn out to be cumbersome, like the brown chest straps that helped link the seat kit to the harness. Using the lower fittings like the RJE fitting could seem to be more streamlined and the need for the chest straps ( fumbly things) could be eliminated. Evolutions are not always well documented, especially in times of war. The US Army created a quick approval system for needed changes through ACTIV and AMMC offices in the theatre. The documentation could be introduced locally very quickly and could have taken time to be implemented in other areas.

The harness you show seems to predate the seat kit version that are on the seats I have, it doesn't appear to have the RJE fittings at the waist/leg. It doesn't match either of the two harness's shown in the book. This is an illustration of evolution that doesn't get documented, at least in the book you possess. The harness I have doesn't match the book either. ALSE shops have proven to be quite adept at producing interim hardware when needed.

 

IH

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Those aren't RJE fittings on the waists of the quick fit harnesses. Those are just "accessory rings" as used on all USAF harnesses. They are for those green colored push button release fittings used on AF survival kits. If you have seen the later adjustable J5D seat harnesses, the Army used the accessory rings to pass the free floating lap belt through.

 

The diagrams shown in the 1962 -10 only show the harnesses in general, doesn't show the vertical straps, but you can see the adjustment fittings are there, as well as the lower RJE fittings aren't shown on the MA-2 to simplify the drawing. If you ever see the full body suit MA-2s, the lower fittings hide inside the suit at times. They apparently wanted De-cluttered basic diagrams of the harnesses. All MA-2s have that lower lap-belt.

 

Here are some pics I took of both the accessory rings, and RJEs and how the RJE cannot function with the accessory ring:

 

Accessory ring with the appropriate connector buckle:

AR2.jpg

AR3.jpg

 

Accessory ring compared the RJE:

ARRJ.jpg

 

RJE male and felmales:

RJ1.jpg

RJ2.jpg

RJ3.jpg

 

 

My harness is August 1967 dated, Made by Pioneer and is also stamped with a Grumman part number for the OV-1 starting with 134. This one never had the rings on the hips as I couldn't find a place where they might have been removed. Id say these harnesses were specifically made like this at first and then Pioneer just installed the accessory rings on them afterwards to streamline their production as its a similar harness to the PCU's the Air Force used and still uses. I have seen pics of OV-1 crews from the early 70s in Nam with harnesses that has the rings at the bottom but they served no purpose. Most of the earlier pics Ive seen from 1968 and earlier I didn't see the rings.

 

Much like you said Da Nang had Navy life support influence, Id say that's why your belts have the lower RJEs for using MA-2 harnesses with the seat. Could be earlier lap belts had the RJEs for using the MA-2. MA-2 wasn't even mentioned in the later OV-1 manuals. Ive seen these lap belts that don't have the RJEs install on them, and a friend of mine that flew OV-1s from 1964 to 1970 said they never had them on any of their seats. He said the only RJEs they had were the riser fittings and used the standard lap belt with the 2 vertical straps.

 

He was stationed at Marble Mtn. 1968-1969 which also had Navy influence with the Marines being there. He sent me a pic of their ALSE shop and they had both a Air Force mesh net SRU-21/P survival vest and a Navy/Marine SV-2 survival vest on display. Thats probably where the idea to combine the 2 and create the OV-1 specific survival vest came from after those years of experiences. Early OV-1 flight gear is a big mix bag of Navy and Air Force stuff, its too bad there's no real solid documentation to all the differences and local changes made during the Vietnam era.


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Well, I have to stop working from short memory and be specific about this as I am not interested in this paraphernalia on the whole. When it was some specific need, I looked and learned, otherwise it's stuff I don't need to know. I went out into the storage where the seat and harness are and pulled out the harness. Since there are already pictures of the seat and straps, I don't need to revisit that. This entry and the next entry show the harness in whole. What service originated it I have no idea. The remains of a tag say PIONEER on it and little else. The upper riser connection are Koch fittings which are set the way the Navy attached them, male on the harness, female on the risers. The USAF did this opposite so this harness seems to indicate Navy use. My seat has the female connections on the pack risers so this seems to indicate a Navy use parachute pack. I have no clue as to what the style of criss cross on the back or the chest strap connection are common to.

 

IH

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I believe that is known as the MA-2P harness. They were originally designed for use by the Navy wearing high altitude pressure suits I believe? Navy guys chime in if see this. The MA-2 if cut out of its suit would looks very similar to this. About the only difference is the use of a V-ring and ejector snap for the chest strap vs a friction buckle like on a standard MA-2 You can see they sort of kept the idea of the vertical retention straps that attaches to the lap belt area tacked in place. If you also look at the later J5D seat "fitted" harnesses, they have the same overall strap setup as a MA-2 much like this one but a few differences here and there.

 

Its very possible they could have used these harnesses at one point somewhere locally in the early 70s. Like I said, I once saw one of the regular quick fit harnesses like mine, the old version with the vertical retention straps, but they were cut off and the RJEs were cut off and replaced with the upper later koch fittings and used the free float belt for the D model. There was surely an intermediate period between the use of the J5A and B seats to the D. Koch fittings are much easier to operate and seem more secure than RJEs so they Army may have been fooling around in the early 70s before going into the D model seats. OV-1 ALSE is very sketchy for details and actual documented history between its introduction in service til around 1974.

 

Too bad you didn't still have that whole OV-1D cockpit around, you should post the pics of it if you still got em on here.


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Here is the lower end. The leg loops are non adjustable. Added to the harness are the chest support straps for the seat kit and a belt lap type strap has the RJE fittings on it. You can see by the wear on the belt material that it was added to the harness to accommodate the need for the RJE fittings. This could have been Koch fittings just as well if being used in a Navy use ejection seat like the F7. The evidence here points to a Navy harness that could conceivably have been used on both a Navy F5 seat and an Army J5 seat. The Navy later upgraded the F5 seat to an F7 seat with the use of a parachute pack as used in the H7 seat and it upgraded the seat kit and switched to using Koch fittings for it. If I put this on and sit in the seat everything clicks into place without any difficulty. If I were able to find a correctly restored Navy MkF5 seat the harness would probably work.

Interchangeability is obvious. Not all pictures tell the whole possibilities of truth. Just because one guy swears to something doesn't mean he's right or wrong. It means he knows a part. Other parts of the story can exist without his knowledge. It's just like the fact that one guy remembers there being a metal firing handle in the lower position and that's all he remembers. That doesn't negate the fact that the handles were changed to a slightly larger flexible handle for user ease. You can see it in the restored seat I have. I didn't put it there, it is installed in a metal shroud and takes tools I don't have to take off or install. It's a seat shop instal.

This has anecdotal history, nothing in concrete. Basis in truth is demonstrated. Is it one of kind? I hardly think so. It's just one that survived.

 

IH

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I agree with what your saying, that's why I say the OV-1 history is very sketchy especially. Theres no one way to it at all. Things changed often, especially during war time. There was def no one way to equipment back then, flight gear or field gear related. Look at how our field gear has transformer from 2001 til now, its crazy.

 

Both of those handles were used, the small gold colored metal one was just the old style and hard to grasp. The seat you have for sale has the older small handle if I recall right from one of our conversations a while ago? Cant see in these pics you posted here. The bigger flex one seems to have worked well and carried it over to the J5D. Ive seen some J5D seats that had the old rounded upper firing handle too. Everything's mix match, and as you've said before those changes don't always make it into a publication. Any idea why they replaced the rounded upper handles to the later triangle shape?

 

Interesting little note, that pilot I know never had to eject, but said if he ever did he would have fired the lower handle and went through the canopy vs jettisoning it (time permitting) prior to pulling the firing handle. I guess from other crews experiences that ejected, they said that all sand and other debris that was in the cockpit would fly all over the place when the canopy was jettisoned and get in your eyes etc.


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Yes, the for sale seat has the metal gold/black handle. As for J5D seats having rounded handles up top, I would say it's a definite possibility. The rigid pointy looking one came after crews observed that it was easier to grasp with two hands and hence a more positive force in pulling.

Both handles on the seat would initiate jettison of the canopy. The canopy could also be jettisoned by itself, say in a water landing scenario where you would want to get out quickly. Trying to egress out the side hatches would be precarious as they only swung open 50%. Tough to get out of there. Why your friend did not know that both handles would jettison the canopy is beyond me. The seat system has electric and charged initiators as well as cocked initiators. In the eject sequence ( either handle) one electric initiator caused the canopy blow off system to activate. This was a 200psi compressed air canister located behind the cockpit wall that rotated the unlock device and allowed the canopy to be released into the airstream and be blown away. There was delay built into the system to allow this to happen to prevent any crewman from colliding with the canopy frame, which is heavy and solid. While there was delay, wind stream could blow any dirt and debris there was in the cockpit all over the place. Since the canopy did not jettison with a charge of any kind, there would not be any blow back into the cockpit. I don't know if this was the sequence in the first series of aircraft but it definitely was in OV-1B and later models. If I was having to eject from an aircraft out of control it would be difficult to have to preform two actions to eject as opposed to a single action, pulling a seat handle. Having blown off the canopy at say 200kts the wind stream into the cockpit would probably make it very difficult to make timely movements to eject. It makes far more sense to have the whole sequence be initiated by one action, pulling a seat handle.

 

IH

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Here is a photo of the canopy jettison switch located behind the seat. It was mounted on the bar that ran transverse across the back of the ejection gun. This bar is where all the manual trips were fastened, each of these would pull as the seat ran up the ejection gun. Fastened on the seat was an arm that would contact the switch and hold it closed. This switch was tripped by motion of the seat, either handle that was pulled started that motion. You could not pull the lower handle and expect that the canopy would stay in place. The seat would travel an initial short distance allowing the switch to be released and starting the blow off mechanism of the canopy. I don't specifically know the delay time but it must have been measured in seconds or fractions of seconds. This sequence and it's timing is designed to allow the slipstream over the aircraft to blow the canopy up and rearward creating the clearing for the seats to exit the aircraft. No pyrotechnics was used in this part. The canister charged with 200psi of compressed air just rotated the internal locking arms that held the canopy in place and raised the rear edge of the canopy upward and rearward away from the cockpit. The actual movement of the seat was achieved by explosive charges located along the ejection gun which created gas in the tube and propelling the seat up the ejection gun rails. Also set in motion was the drogue gun mechanism which delayed a couple of seconds then detonated a charge which shot the drogue bullet up and away from the seat and allowing the drogue parachute to start it's deployment. The time release mechanism was also running and when appropriate it released the fasteners that held the parachute pack and seat kit. As the drogue fully opened it would allow the crewman to separate from the seat and begin deployment of the parachute.

As I said, all of this was present on OV-1B and subsequent aircraft. Maybe it was different on the A model and if it was more complicated you can see why the process was streamlined.

 

IH

post-12336-1326664790.jpg

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Ok now I'm thoroughly confused. Out of all the pubs I have for the OV-1 ranging from 1962 til the early 1990s, none of those mention an automatic canopy jettison upon starting the ejection sequence after pulling the firing handle. Ive looked through -10s, CLs, maintenance manuals for both the J5A/B and the J5D seats as well as both the J5A/B training circular from 1968 and FM-55-43 for the J5D seat and found nothing to state that at all.

 

Do you have a OV-1B -10 or a seat manual or a source that states what your saying?

 

Both the Early J5A/J5B TC and the J5D FM say time permitting the canopy may be jettisoned.

 

It states "Primary means of escape is to eject through the escape hatch cover (canopy)" "Time permitting, the aircraft is placed in a shallow climb and the overhead canopy is jettisoned by rotating the jettison handle 90 degrees clockwise"

 

Also, can you take a pic of the above piece farther back? I couldn't seem to find that switch shown in any of the maintenance manuals. That yellow bar looks like the Drogue Gun Trip Rod. Is the bottom of the rod attached the rear cross beam? I know we both agree manual diagrams leave stuff out but I couldn't find it on an actual picture either in the manual where the Trip Rod is shown.


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You know, since you have all the books that say what the procedure is let's just declare that is way it is. The rod you see is the bottom of the drogue trip rod. And as you say, the books don't always say or show what is really there. At least the book you may be looking in.

 

IH

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You know, since you have all the books that say what the procedure is let's just declare that is way it is. The rod you see is the bottom of the drogue trip rod. And as you say, the books don't always say or show what is really there. At least the book you may be looking in.

 

IH

 

 

I'm not trying tell you your wrong or argue with you if that's how your taking it, just having a discussion. I think its actually nice for a change to discuss the OV-1 since its not a well known aircraft. I'm not trying to to declare I'm an expert either or trying to sharp shoot you etc, just trying to take what I gather here and learn more. Id like to learn more about what your saying since I hadn't heard that previously til now. Only asking for you to elaborate on that and curious to know what source that's from.


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