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Jettison able Canopy

Rhino889

Well Known Member
Jettison able Canopy:

No one ever wants to ditch a canopy… but it might be useful to do so in certain situations.

My mission profile is 1000ft down the beach enjoying the view, aerobatics and occasional flights with the wife down in the Bahamas’ island chain.

I’ve read at great lengths regarding the 8’s canopy and getting out in flight while tumbling around. This is a possible concern, however for me ditching in water situations is also a possibility. The thought of a ditch at sea while your passenger is sitting back there, most likely still cocooned under the canopy... not good.

From what I’ve read, most guys put quick-disconnect pins where bolts normally go for connecting the rollers and canopy bow. Some have suggested both pulling the pins in emergency situations and also flying with the pins completely out (downward and forward air pressure on the canopy).

I’m not comfortable flying with the pins out. I’m sure it’s fine and I don’t question others for doing it. It’s just not for me.

Pins engaged causes a problem in my mind for VERY rapid jettison and exit. Too many steps:

1. Rotate canopy handle for disengage of latching mechanism.
2. reach left, find pin
3. pull pin
4. reach right, find pin
5. pull pin
6. PUSH UP and BACK with everything YOU GOT!

* I separated the find and pull steps to illustrate the time and effort of performing this task under tumbling situations.

My solution cuts down the steps to:

1. rotate canopy handle for disengage of latching mechanism
2. pull back while giving UPWARD pressure. (upward should be natural in this situation)


I’ve spent some time trying to figure out a simple (USMC style) solution to this problem. My desire was to have something quick and natural, something you do every time you exit the aircraft.

RV-8/8A factor: The “cool” things about the RV8 canopy system. I want to be able to open the canopy 3-4 inches in flight (Florida heat) and taxi with the “Cool-guy arm on the rail”. I won’t make excuses, I want to look cool! With that in mind I made sure these two factors were retained.

I plan on cutting out 3 inches (3x roller diameter) of the roller track’s upper cap. Approximately 15 inches and extending to 18 inches behind the front canopy bow. This was determined for me personally using seat back rest and leading edge of my shoulders. I place the cut-out before the shoulder because of “cool-guy arm” position would dictate canopy locked into position behind shoulder. This cut-out position also gives a 10+ inch buffer behind my inflight open canopy position. Should the canopy somehow become unlocked from the inflight position, the downward and forward air pressure on the canopy would have a margin for ????. :confused:

The only other player would be on the ground while loading people. I think we can all agree that gravity will retain the roller for 3 inches while traveling forward-rear-forward.

Scenario 1: Tumbling from doing a maneuver reserved for MX2/ Extra aircraft. Wing left about 20 seconds ago! Time to try and catch it leaving fuselage behind! Dang, guess those engineers know what they are talking about!?


1 rotate canopy handle for disengage of latching mechanism
2 pull back while giving UPWARD pressure.

Once rollers get to cut out: Canopy gone…
Time to go skydiving:eek:

Scenario 2: Flying with wife over open water. Engine quits/ Fire onboard/ etc.

1. Within couple 100 feet of water and slowed (possible canopy impact with HS, slow speed reduces blunt force trauma on HS)
2. rotate canopy handle for disengage of latching mechanism
3. pull back while giving UPWARD pressure.

Once rollers get to cut out: Canopy gone…(hopefully)
Time to go swimming:(

I present this to the group for input and ideas. It’s always better to get as many different opinions on a safety subject like this. I’ve left some thoughts out to allow for free exchange of ideas. Instead of just countering mine, I’d like the clean slate approach. I figure someone has thought of this or done this by now? I haven't been able to find anything with the searches?

Hopefully nobody ever needs this modification, but hey $h1% happens!

Disclaimer: I do not recommend this and I have not tested it. I am just a pilot, not an engineer.

These are some rough cut up scrap. Final product would have nice rounded edges and look better.

7f06f36a.jpg



1753d2e7.jpg

Maintaining the structural form

036b937d.jpg

Blue tape is position of my cuts (determined by pilots shoulder+seatback)

8711f70b.jpg
 
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Sure seems like it would work, but then I only want an 8, dont really have one bit of experience with them.

Pretty sure one of the 8 flying guys will chime in sooner or later.

Good use of out of the box thinking.
 
Rhino,

I like your idea. The only risk I can see is maybe normal ops on the ground in heavy winds. If a gust caught the canopy as it was transitioning the 'gap' in the tracks it might make an unplanned departure - probably a remote possibility.

I have the pins in mine, and they are definitely not a perfect solution. I don't mind flying with them out, but I fear I'll forget them and damage my canopy (same wind gust or prop blast scenario) on the ground with it open or partially open.
 
I have thought about this as a safety issue on RV's for years. I, have no engeneering data to confirm the safety of the modification so I never did it. Van did not recommend it as there is a rear canopy pressure that complicates the issue. I don't know about other complications that he may have understood. I am a skydiver and have considerations of actually exiting the cockpit. There was an RV pilot that did exit his RV from the air due to a likely cockpit flame out when the canopy was unsecured. Good safety issue to consider. Hopefully this issue will make some progress with other's input.

The partially open option for in flight, (2-12 inches,) has been discussed by many RV pilots and builders over the years. Van does not approve it though. Needs more research. I have heard a few others say that it is really hard to slide a slider to the rear while in flight. Pressures on rear of canopy while in flight. Never tried it myself. It would be a nice option for some of us.

The jettison issue is a question of if the canopy could be moved to the rear and then pushed up into the airstream for the jettison. It seems that if a person could lift the canopy up an inch or so the slipstream would take over with removing the canopy.

I am not an engineer and I have no practical experience with this issue. All my comments are opinions only. I look forward to what other's input will contribute.
 
Like Strega.

The unlimited P-51, Strega, doesn't have a lip that the canopy slides under. It merely butts up against the windshield, so there's no restriction to the canopy simply leaving upward, not being retained by the lip.

I looked at it at Reno and it's a really nice, close fit...might consider that as well. Have no clue as to how noisy that might be tho',

Best,
 
I would think that you would be better off with the opening at the front of the rail. That way, you will have help holding it down with the windscreen fairing (canopy slides under) and being at the first part of travel you will have your hands on it to open so won't have to worry about any gusts while on the ground. Also less time to open in emergency, just clear the windscreen fairing, which is just shy of 1/2" on mine.

Whatever you choose it would be good idea to mark the area in red, visible to thhe pilot from inside to know where it is.
 
Its a good idea, but, in the heat of the moment, pulling back and up 'just right' to get the rollers up and out of the track may be easier said than done. (Imagine being a little too aggressive on the aft vs the up and overshooting the slot)

I have no idea on how to do this, but how about a 2 action system.

1: Unlatch canopy lock.
2: Pull Canopy jettison handle(s)... the action of this handle(s) is to pull back on canopy and raise a ramp inside the rail that guides the rollers up and away through your cut out. I dont think the mechanics of this would be too tough, and the big red jettison handle(s) would look cool as well.
Imagine aft sliding handles on both sides that pushes up on a triangle wedge mounted below the rail that push up through a slot. The wedge is a ramp to guide your rollers up. The overall travel of the handles would only have to be about 4 inches.

Chris
 
Where Did You Get the Extrusion that You're Using?

Scott:
I could be wrong, but it appears that the aluminum that you're using is the hardware store variety. If that's the case, you should be aware that there's a big difference in strength between aircraft alloys and what might be used to frame a screen door. Most wrought aircraft product goes thru some sort of secondary heat treat process and also is typically formed with fillets and radii.
If it isn't aircraft grade, DON'T USE IT. Certainly not to help hold on your canopy.
Terry, CFI
RV9A N323TP
 
Great Thread Rhino

Gotta love this forum for exploring experimental ideas with real world experiences.

Seriously considering your idea as I don't see a downside. I have the little cam over mid position stop and would cut my track to make sure there is still both up & down restraint while taxiing.

Someone mentioned flying with the pins always out. Other than remembering to reinstall when on the ground, has this system worked acceptably?
 
....
I?ve spent some time trying to figure out a simple (USMC style) solution to this problem. My desire was to have something quick and natural, something you do every time you exit the aircraft.
....

I'm not sure if this is the logic you want.

If it's something you do as a normal exit then you risk have a loose canopy on the ground every time you get out.

It's a bit like glider pilots not wanting to get out of the cockpit with their chutes on - so they instinctively un-buckle both the seat belt and chute harness on every normal cockpit exit.

It has been known for pilots (but maybe an OWT) to undo both harnesses and then jump in an emergency.

Your emergency action should be easy, but different....:)
 
Scott:
I could be wrong, but it appears that the aluminum that you're using is the hardware store variety. If that's the case, you should be aware that there's a big difference in strength between aircraft alloys and what might be used to frame a screen door. Most wrought aircraft product goes thru some sort of secondary heat treat process and also is typically formed with fillets and radii.
If it isn't aircraft grade, DON'T USE IT. Certainly not to help hold on your canopy.
Terry, CFI
RV9A N323TP

It's actual canopy rail ordered from Vans. You seem to get some scrap when the first attempt is not satisfactory with alignment and you order new and start over.

To be clear: This is RV8 canopy rail, not a sliding screen door.
 
2: Pull Canopy jettison handle(s)... the action of this handle(s) is to pull back on canopy and raise a ramp inside the rail that guides the rollers up and away through your cut out. I dont think the mechanics of this would be too tough, and the big red jettison handle(s) would look cool as well.
Imagine aft sliding handles on both sides that pushes up on a triangle wedge mounted below the rail that push up through a slot. The wedge is a ramp to guide your rollers up. The overall travel of the handles would only have to be about 4 inches.

Chris

Chris,

I really like this idea! Going to look into it. Red and white striped handle and when the wedges pop up, wedges are striped as well.:D

Very cool idea, thanks for sharing the recommendation.

Scott
 
adding to the idea:

Removable bridge that spans the opening.

In normal operation everything stays the same. If an operation that might require whats being discussed is planned, then the bridge can be removed and the system is "Hot".
 
I'm gonna watch this thread!

I lke ths idea! After flying Pitts and Extras for almost twenty years, having a jettisonable canopy is a must for me on my -7. I plan on wearing my chute at all times, as I did in the acro planes. I have researched it on this site but am not at the point of designing mine yet. I really like your idea, I do remember from talking to someone years ago, maybe at Aviat, that on a certified acro plane, the canopy, or door as it may be, had to be jettisonable in no more than three separate actions. Obviously not required on an Experimantal, but still would be a good idea.

I was thinking along the lines 1. open latch, 2. pull removeable pins in the rollers, and then 3. a mechanism that forced the canopy up into the slipstream. Maybe pulling a handle that rotated some steel pins up into the track and against the bottom of the canopy. That way you would not have to force it up with your hand, running the risk of smashing your hand through the plastic. The idea of a handle to both pull it back and force it up when necessary would be even better. Apparently getting it back against the slipstream is the hard part.

Please post more pictures as you go! I promise to do the same when I get to that point!

Damon
 
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How about an emergency actuator to do two functions.

1) To remove bridges to expose the open rail areas, as others identified.

2) To raise ramps, (wedges) to force the rollers up and out of the rails through the removed bridges.
 
Gotta love this forum for exploring experimental ideas with real world experiences.

Seriously considering your idea as I don't see a downside. I have the little cam over mid position stop and would cut my track to make sure there is still both up & down restraint while taxiing.

Someone mentioned flying with the pins always out. Other than remembering to reinstall when on the ground, has this system worked acceptably?

Hi dbuds2, I've flown my airplane during acro with the pins out. No problems. HOWEVER----I was talking some 2 months ago, with the guy I bought the plane from, and he says he wouldn't do acro with the pins out. So probably I won't do anymore. Mixed answer--huh?:mad:
 
Pins on a 6A-word to the wise

I have had the small pins on my 6A canopy since I built it. I have pulled them and removed the canopy many times for mx. It has been several years since I removed them until earlier this week. It had been at least 2 years and they had light rust on both pins and the canopy bow-to-rollers.

Therefore, if you are counting on removing pins for a bailout, you'd better lube them often. No way mine would have come out by hand!
 
If canopy come lose in flight, do you think it can damage de VS/HS seriosly?


If you loose the canopy in flight at speed it could sure damage the VS and/or the HS. Unknown if it will for sure.

That situation is what the parachute is for. You are going to bail-out anyway.

Be prepared - be safe.
 
idea

Maybe the bridge could be the ramp. What I mean is the top of the track could be cut out and hinged in the back. When the handle is pulled the bridge drops down and acts as the ramp to guide the rollers up and out of the track. Just an idea.
 
I started a thread like this about 2 years ago. I had pins in my canopy which I took out before takeoff. Since the seat backrest is unmovable, I noticed that putting my parachute on moved me forward a good 2 inches putting my knees about 2 inches under that nice sharp bottom edge of the instrument panel. Y'all get the picture.:eek:

For that reason, I used to practice (in the hangar) as best as I could, getting my knees up and heels on the edge of the seat before falling out after rolling upside down. As I said, I could only try to think about it and practice since I couldn't do the real thing. Something to think about.:rolleyes:
 
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My Solution for my 8

I am planning on wearing a chute for testing and aeros. So I thought about how to get the canopy off quickly if need arises. So I decided to put removable pins in the sliding canopy frame where the rollers attach. Plus add a handle to the right side because the left side already has the locking handle. So if I need to get out pronto I pull the pins grab the handles pull the canopy back about 2 inches and push it up so the slipstream carries it away. If the force is too great then I can stand up and push with my body.

See the photo below.

http://i1086.photobucket.com/albums/j448/jimboscr/IMG_5186.jpg


Jim
 
I Will Follow this one!!

Very interesting thread. !!!

Having thousands of hours in "normal" airplanes, I never flew with a chute, nor ever made a jump...

Now, as part of my future experimental plane, at this stage I'm considering the possibility of a jettisonable canopy and chutes...

Having the equipment and option to bail out in what would be a last chance at survival (airframe failure/uncontrollable fire...) is a good thing to have.

However, I never jumped, don't have any experience in jumping and would like to avoid it if possible.

What would be the probability of someone that never jumped expect a good to very good chance of getting away with it??

What about an occasionnal passenger that never jumped???
Imagine saying: "Hi there, here, wear this even though you never jumped, it's in case of an emergency but we won't need it right...:eek:"

Any thoughts or experience on this ???

Many thanks !!!
 


I'm very interested in your picture, as I plan very much on having a jettisonable canopy in my plane and wearing a parachute at all times, but as I haven't gotten to the canopy yet, I don't really understand what I am seeing here. Could you elaborate a bit on how yours works?

Thanks, Damon
 
I'm very interested in your picture, as I plan very much on having a jettisonable canopy in my plane and wearing a parachute at all times, but as I haven't gotten to the canopy yet, I don't really understand what I am seeing here. Could you elaborate a bit on how yours works?

Thanks, Damon

Looks like the system that a lot of guys have talked about: the bolts attaching the canopy frame are replaced with pins. In this particular case, they have a nice big bright red collar to pull on when you need to get them out.

That's what it looks like to me, but stand by for the official response. I just bent my rudder last night, so I shouldn't be considered a reliable source on canopy construction.

:D
 
Looks like the system that a lot of guys have talked about: the bolts attaching the canopy frame are replaced with pins. In this particular case, they have a nice big bright red collar to pull on when you need to get them out.

That's what it looks like to me, but stand by for the official response. I just bent my rudder last night, so I shouldn't be considered a reliable source on canopy construction.

:D

Ahhh..I see what confused me...the red collared pin at first looks like what the latch went over when the canopy is latched shut, when in fact that pin must be out of the picture to the right. Makes sense now. Thanks!
 
Innovate!

I'm very interested in your picture, as I plan very much on having a jettisonable canopy in my plane and wearing a parachute at all times, but as I haven't gotten to the canopy yet, I don't really understand what I am seeing here. Could you elaborate a bit on how yours works?

Thanks, Damon

Damon,

The AN3 bolt that holds the roller to the canopy frame is replaced by a 3/16 inch diameter pip-pin. A large concave washer (these were used to hold the rubber bushing on a 1965 Chevy Bel Air convertible shock absorber) is under the head of the pip-pin and a short length of soft rubber hose (mine found attached to a rubber bag I found in my grandmother's bathroom, under the sink) is beneath the washer to hold it away from the frame enough to allow your fingers to fit behind the washer. You need to buy pip-pins long enough to allow the washer to stand clear of the canopy frame, but not so long that they interfere with the cockpit brace that the pilot seat rests on.

Chevy Bel Airs are a bit hard to find, but keep looking. My grandma was real upset that I shortened the hose on that little bag, so you're on you own to find a suitable replacement.:D
 
Damon,

A large concave washer (these were used to hold the rubber bushing on a 1965 Chevy Bel Air convertible shock absorber) is under the head of the pip-pin

I thought that washer looked familiar!:D

Thanks for the elaboration, I like your system, it looks nice and simple, just right!
 
Canopy options

Two ideas that work.

The early Siai Marchetti SF-260's had bungee cords that you stretched to close the canopy. They were attached to the front and anchored at the rear. All you did was open the canopy and the bungee's did the rest. They overcame the reverse air pressure trying to close it. It was so simple I did this to my -4 with a slider when I wore a chute.

Latter 260's had 3 or 4 pins on the bottom of each canopy rail. each pin had a hole through it facing FWD & AFT.
Below each rail there was a rod that had a short U shaped rod laying on top and on its side welded to the top of the long rod. The U shaped rod went through the canopy pins. It ran through some support blocks and allowed about 2" of FWD & AFT movement. Moving it FWD allowed the U shaped rod to pull out of the pins and the canopy and rails departed the A/C in flight.

At the front of the long rod that ran below the canopy with the horizontal U's, it had another rod that was pinned to the front end of the long rod, and it hung down 8 to 10" below. That rod had a pin through it about 2" below where it was attached to the horizontal rod. The rod that extended below the pivot was the pull handle. The U shaped anchors that went through the canopy rail pins only had to move about 1/2" to disengage the rails. Both canopy pin actuators were tied together R to L. There was A handle on each side of the A/C, either would pull the pins.
The right handle had a small copper indicator wire twisted over to an small tab from the end of the handle. If you pulled the handle, it broke the wire.

All you did was unlatch the canopy, pull the handle and get out!

You looked to see if safety wire was intact prior to flight. The canopy and rails for the SF-260 was a little over $30K. I was told if you pulled and the canopy came off it would take the top 1/3rd of the tail off. I know someone who lost one in the winter after some work and the U shaped pins were not engaged properly. I don't think it had the indicator wire in it. I was told it got very cold and windy. It didn't take the top of the tail off either.

There were also little 2" round inspection plates you were to remove at each U shaped pin area to ensure all were in properly. I did this anytime I had my canopy off.

The SF-260 as well as my -4 is open about 4" prior to landing when it is hot out. The 260 was allowed below 125K, I do my-4 below 110K. You can make something to hold it open in flight while landing.
 
Nitrogen bottle or Explosive Microcharges

I hope it's not too late or has been mentioned before but a good friend of mine who happens to be a very skilled and trained pilot suggested adding a bottle of compressed Nitrogen as a probable ways to jettison the canopy altogether with the rails themselves.

He's gonna help me design this system so as to not interfere with normal movements inside the cockpit, accidental activation, normal entry/egress of pilot and passenger and even FAA certification.

He also told me there are small screws that contain self-destructing (explosive) micro charges in them and are specifically designed for this sort of purposes (like for fighter jets, but not as expensive or complicated).
They can also be used in the rail system and probably be activated with a safety switch conveniently located for emergency purposes.

Just thought about posting it here so that you wise builders can have another option to think about and keep your minds busy with.
 
:eek:

That sounds like its more likely to cause an emergency than cure one. Explosives in my cockpit? No sir, not this marine. Neither electrically triggered nor gas discharge. I would rather twist a handle and push upwards....nothing accidental about my intentions in that case.
 
It's a safety issue

:eek:

That sounds like its more likely to cause an emergency than cure one. Explosives in my cockpit? No sir, not this marine. Neither electrically triggered nor gas discharge. I would rather twist a handle and push upwards....nothing accidental about my intentions in that case.

If you drive a car, you most likely ride with more than a couple explosive devices right in front of your nose. They are called airbags. In the unfortunate event of a collision they explode and then inflate.

First link is a little bit of theory: http://en.wikipedia.org/wiki/Pyrotechnic_fastener

Second link is a provider of the fasteners, or separation bolts themselves.
http://www.hstc.com/Products/OrdnanceProducts/SepBolts/

Like I said, it is something to open a discussion, which in fact has started. I value your opinion and your point of view, but I believe there's more involved to it than just the words "explosive" and "charges".

"They" said it was a crazy thing to put emergency parachutes in a Cirrus because of accidental deployement. They have saved many lives and yet no accidental deployment has been registered to date.
 
I understand and I too appreciate a good theoretical discussion. Please take no offense as this is mostly just a mental exercise and reminiscence of the old days.

It's nice that air bags have come up, as following the Marines (Hawk Missiles electronics) I was on the design, life test and implementation team at Chrysler when we first brought air bags to the states. There were a lot of lessons learned in those early years and quite a few accidental deployments, injuring people in their new cars. Engineering lessons learned, changes made and now the systems are very good...but it should be noted that they were not always so and it took quite a bit of engineering to get them where they are today. We weren't designing something from scratch...we were copying the Germa...uh, never mind that for now. Besides things like static electricity and voltage spikes causing things to pop, one early lesson on air bags was that an explosive going off in a sealed environment had the same effect as a flash bang grenade used by police and military. The occupant was stunned, often times causing accidents. That led to 2 stage deployments etc trying to reduce that stun as well as many many changes trying to eliminate accidental deployments. Those accidental deployments still take place though.

Video
Link
2012 recall for accidental deployments

After discovering that the sun in Orlando shines more than Detroit I moved to Martin Marietta (now Lockheed Martin) where we worked with quite a few electrically triggered things that went boom and still more lessons were learned.

I say all of that to say this. The difficulty in designing a system of explosive bolts in an RV is if you do not consider even one of the mistakes that we as professional 'blow it up' engineers made...the experimental pilot/engineer may not get to learn that lesson and apply it to version 2.0....because the departing canopy can take his empennage apart and there may not be enough of the wreckage left to determine exactly what caused the accidental deployment. The explosive bolts work very well in a military jet where the seat is going to remove that pilot from the plane regardless of his mental capacity or the aircraft's ability to remain stable when the canopy departs. Even after spending millions on engineering and a ridiculous amount of life testing...military ejection seats/canopy releases are still accidentally deployed, either electrical malfunction or some odd operations mishap that hadn't been planned for. A google search will bring up many stories, but here are a few.

Link 1,
Link 2,
Link 3
Link 4

In the case of an accidental deployment in our beloved RV's, the pilot will have to unbuckle, depart without hitting his head on the HS (something I also have experience with and it's not easy to do in a short aircraft like an RV) and deploy a parachute...all after being stunned by a flash bang with 200mph wind in his face and an aircraft likely going through some unusual attitudes. Anything electrical can accidentally fire and anything with a switch or a handle can accidentally be thrown or pulled.

Again, please dont take this as a dismissal of an interesting idea. As it happens, I have a bit of experience in this area so I'm just sharing. Of course, there are ways around every engineering problem given enough money, time and weight and I really would enjoy going through such an attempt...as long as someone other than me is flying it and he tells me in a very clear and untroubled voice that he doesn't mind the consequences of an engineering oops moment.

"It was odd Bill, I was in the pattern and deployed the flaps, turned on the fuel pump while pressing the push to talk...and the canopy departed"

Hmm...that shouldn't happen. Ok, we will look into that. :D
 
I stand corrected

I understand and I too appreciate a good theoretical discussion. Please take no offense as this is mostly just a mental exercise and reminiscence of the old days.

....

Dear Bill, given your through explanation, plus your definitive expertise on the subject, I stad corrected and informed.
Thanks for your valuable input. This of course, was a crazy idea someone with no airplane building experience presented to me. He will also be given this feedback as well.
It is a very interesting subject, but the fact of riding with my wife/kids/friends/mother-in-law and suddenly looking at the canopy go bananas into the wind because of a possible misfire scares the guts out of me (I'd love to see my mother-in-law's face however)... :p

When I went to bed last night, I kept thinking about all thise little details that could go wrong. I also considered the possibility of having the remaining bolt fragments and shrapnel flying at the occupants ar supersonic speeds, probably even creating more damage than benefits. That gave me even more chills than the fact mentioned above.

I don't think I will be carrying on with this theory or experiment when the time comes to work on the canopy and cockpit, but I will keep thinking about it and making updates on new findings, if any, about new emergency egress procedures.


Thanks again
 
I am planning on wearing a chute for testing and aeros. So I thought about how to get the canopy off quickly if need arises. So I decided to put removable pins in the sliding canopy frame where the rollers attach. Plus add a handle to the right side because the left side already has the locking handle. So if I need to get out pronto I pull the pins grab the handles pull the canopy back about 2 inches and push it up so the slipstream carries it away. If the force is too great then I can stand up and push with my body.

See the photo below.

IMG_5186.jpg



Jim

Jim,

Is the B-type spring pin what you are using in lieu of an AN bolt? (I'm not sure what the gray thing is aft of the spring pin that looks like a car door lock.) Yours seems to be oriented fore and aft, where Smokey's pin is oriented side to side.

I wonder if you could use a short removable lanyard to your pin that would be anchored to something forward of the canopy when it's in the closed position. For normal operations, you would unhook the lanyards before opening the canopy and the pin would remain in place. But in an emergency, you just open the canopy a few inches, the lanyard retracts the pins and then you push the canopy up into the slipstream.
 
Jim,

Is the B-type spring pin what you are using in lieu of an AN bolt? (I'm not sure what the gray thing is aft of the spring pin that looks like a car door lock.) Yours seems to be oriented fore and aft, where Smokey's pin is oriented side to side.

I wonder if you could use a short removable lanyard to your pin that would be anchored to something forward of the canopy when it's in the closed position. For normal operations, you would unhook the lanyards before opening the canopy and the pin would remain in place. But in an emergency, you just open the canopy a few inches, the lanyard retracts the pins and then you push the canopy up into the slipstream.

This is exactly what I ended up doing. Removable lanyard to "arm" the canopy.
 
I seem to recall an -8 owner (maybe it was Smokey?) saying that his pre-flight check included *removing* the pins once the canopy was latched. That way you don't have to fight the shear force on the pins that results from the aerodynamic lifting force on the canopy. I strongly suspect you won't need to push up after releasing the pins... The canopy will lift on its own due to its curved top surface.

Doesn't the forward bow of the sliding portion sit up against the bow of the windshield? I'm trying to visualize where that ring will hit when you close the canopy...
 
I seem to recall an -8 owner (maybe it was Smokey?) saying that his pre-flight check included *removing* the pins once the canopy was latched. That way you don't have to fight the shear force on the pins that results from the aerodynamic lifting force on the canopy.

Nope, that wasn't me! I once had the canopy unlatch and slide halfway back when I hit zero airspeed in the middle of a hammerhead turn! I was able to quickly grab the canopy (and my hat) and close it before airspeed picked up. I don't recommend removing the canopy pins until you are ready to bail out.
 
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