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  #11  
Old 09-03-2018, 03:14 PM
Gusmax Gusmax is offline
 
Join Date: Jun 2014
Location: Sherwood Park, Alberta
Posts: 24
Default

Is canopy loss a common thing with RV-4's?? It just happened to a friend of mine flying his newly purchased 4 from Wyoming to Alberta. He took off from Cut Bank and lost it over some farmland north of there. He tried finding it, so far no luck. It didn't do any damage to tail. He also lost his Bose headset and sunglasses and it got extremely WINDY!!

Phil
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  #12  
Old 09-03-2018, 05:01 PM
RogerH RogerH is offline
 
Join Date: Aug 2018
Location: Salt Lake City, UT
Posts: 18
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As this was just my first flight in the aircraft after the ferry flight from St. Louis to Salt Lake City I can't offer any insight.

I waswarned by the seller to make sure the canopy was properly locked and to the best of my recollection I did just that on the local flight.

Unfortunately I too lost some prescription glasses. I thought I lost the Bose headset as well but that was recovered from the passenger seat later on the ground. Doubt with the wind even if I could keep the headset on, anything I said would have been readable.

I'd appreciate you sending on the contact info for your friend, as we're in the same boat, well I should say airplane, maybe we can help each other through the experience.
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  #13  
Old 09-03-2018, 05:08 PM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 17
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I think you'll find consensus is: improperly latched. Not fully engaged in the first place, or handle inadvertently bumped closer to open.

Of course no one is going to admit to that

And definitely not me when I lost my RV-3 canopy during take-off. I blame the builder for not having a set of taxi position holes
(They are there now.)

I my case the canopy flipped open with the strap holding it at 90 degrees open. I tried to pull it shut, then remembered: fly the plane! Added power and strap broke, canopy flipped all the way open resting on the right wing, then tore off as it was designed to do. No noticeable damage to tail section. Scratched paint on top of wing where top of canopy rested.

Sorry if this is slightly off topic.

Finn
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  #14  
Old 09-03-2018, 05:19 PM
RogerH RogerH is offline
 
Join Date: Aug 2018
Location: Salt Lake City, UT
Posts: 18
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Freely admit in my case the cause may have been organic in nature, e.g. me.

Thinking that shoulder-harness stretching bit of turbulence just prior to release could have resulted in an inadvertent elbow to the locking lever, not a lot but just enough to set up the chain of events...heck if I know but that seems likely.

Either way, just want to come up with a replacement so I can get back in the air and enjoy the handling & performance of an RV-4, without spending all **** winter learning how and then fabricating the replacement canopy assembly.
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  #15  
Old 09-03-2018, 07:02 PM
RV-4 RV-4 is offline
 
Join Date: Oct 2007
Location: St-Jerome,Quebec,Canada
Posts: 1,016
Smile Canopy Safety Latch

Hi Roger

You mentioned that you may have hit the canopy release lever (Normally mounted just forward of your left shoulder on the -4 ) when you hit turbulence ..

Did you have the RV-4 Canopy Safety Latch installed on your -4 (Oly could answer that if he's online)?? You could get one from Van's..pretty cheap insurance.

It is design to keep the lever closed via a spring maintaining pressure on the mechanism..

I know I don't have it on my -4 but have one handy and will install it as soon as the a/c is out of the paint shop..I came pretty close on a few occasion of hitting the lever with my elbow and that will not have been nice..

Best of luck

Bruno
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  #16  
Old 09-03-2018, 09:56 PM
rmarshall234 rmarshall234 is offline
 
Join Date: Jun 2008
Location: San Diego, CA
Posts: 115
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I would think any of these tilt-over canopies that don't have a "lip" at the leading edge to tuck under, are prone to being accidentally jettisoned if the front pin latching mechanism is compromised for any reason. A friend had this happen on his DR107 One Design. All it takes is a little bit of wind to get under that leading edge and the transition from down force to lifting force, is instantaneous and can be extreme. At least that's how I see it. Sliding canopies that have a fixed windscreen to butt-up against are a different animal altogether.

The tilt/sliding canopy I'm designing for my Acroduster will have a 1.5 inch lip/fairing to slide under when closed for this exact reason.

The good news is that it sounds like from Roger's explanation and from the others, that if the canopy does depart and hits the tail it is likely to be only a glancing blow. Dealing with the aftermath of that however, is something else entirely. Again to the OP...nice work.
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  #17  
Old 09-04-2018, 04:48 AM
fixnflyguy fixnflyguy is offline
 
Join Date: Jan 2006
Location: Winston-Salem, N.C.
Posts: 926
Default What I have seen

First off, Great job getting safely back on the ground..plane will be fixed!
I built my -4, so I fully understand the complexity of the canopy. i also inspect/maintain several other -4's (non-builders) and have found that many have been modified to what folks deem simpler or more comfortable. If built per plans, with the spring installed on the pin tube, and the secondary safety latch installed, I can assure you, it takes effort to open or deploy the canopy in flight. I have recently seen one with no springs or safety catch of any sort that flew open on start-up and severely damaged the frame. I know of others who put a small bungee chord on the latch to hold it aft/locked as a final checklist item. I installed a microswitch that will illuminate a bright red LED in my panel if mine isn't locked, although with the springs on the pin tubes, even unlocked my canopy isn't going to come open. It is literally a 2 handed operation to close/open the canopy. If haven't built a canopy, find someone in your area that can assist you...its one of the hardest parts of building a -4. I hope you can find your departed one and salvage some or all of it.
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RV-4/N76WE
8A7 / Advance NC
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  #18  
Old 09-04-2018, 07:57 AM
Vac Vac is offline
 
Join Date: Jul 2009
Location: Niceville, Florida
Posts: 346
Default “Canopy down and locked - stripes aligned”

Sorry to hear about the mishap, and nice job getting the airplane back on the ground without incident!

When the USAF had issues with the canopy on the F-4, they added a striped tab behind the locking arm and a stripe on the arm itself. When the stripe on the arm was aligned with the stripe on the tab, the canopy was visually confirmed to be locked. I used electrical tape on the inside of my canopy skirt to make one stripe, and wrapped electrical tape around the locking rod to make another. The stripes align when the canopy is fully locked, providing a nice visual warm fuzzy the handle is fully aft and the canopy is properly latched. I also have the spring installed, making canopy operation a two-handed event. The only downside to the spring is that the pins “default” to the closed and locked position causing some sheet metal scuffing when the canopy is inadvertently closed without physically holding the handle forward. The spring mechanism is highly effective keeping the pins fully extended fore and aft.

All the best,

Vac
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Mike Vaccaro
RV-4 2112
Niceville, Florida
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  #19  
Old 09-04-2018, 09:32 AM
acam37's Avatar
acam37 acam37 is offline
 
Join Date: Aug 2012
Location: Lufkin Tx
Posts: 631
Default Hendricks latch

I know people will say that this is overkill, but this is what we did with our latching mechanism. It has a safety lock that makes it virtually impossible to accidentally open in flight and we also added a switch that flashes a red light notifying the canopy is unlocked.
https://vimeo.com/116509137
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Arlie Conner
RV-4 (N124TT) Sold
RV-8 (N269CP) Sold
RV-4 (N684ML) under construction
KOCH Nacogdoches
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  #20  
Old 09-04-2018, 03:01 PM
Finger Lakes RVer's Avatar
Finger Lakes RVer Finger Lakes RVer is offline
 
Join Date: Jan 2006
Location: Seneca Falls, NY
Posts: 37
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Roger-I'm a transplant from NY to Ogden area and have built a RV-6 plus military maintenance background. I'd be willing to help you get the new canopy/tranparency fitted when your hearing returns. PM me if you want some help.

JB
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1998 RV-6, N30JB
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