VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

  #41  
Old 10-01-2018, 08:47 AM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 252
Default

Quote:
Originally Posted by rv7charlie View Post
What kept it attached? The per-plans pop rivets will 'unzip' as soon as the canopy goes open far enough to stress the ones at the front end of the hinge. I discovered that fact right after purchasing my 1st -4, when I was replacing the simple lanyard that kept it from going too far, but did nothing to keep it from slamming shut in a wind gust.

Charlie
Sequence in my RV-3B: Canopy opened 90 degrees, held by strap, then strap broke and opened 180 degrees and rested on right wing. I remembered "fly the airplane" and added throttle to safely make it around the pattern and land. It's very possible that had I been a cooler pilot and only used enough power to climb and fly the pattern near minimum required airspeed, the canopy would have stayed attached. It only tore off when adding full power and getting above maybe 100 mph.

Finn
Reply With Quote
  #42  
Old 10-03-2018, 08:09 PM
RepmikeBrown RepmikeBrown is offline
 
Join Date: Oct 2012
Location: Tahlequah , Ok
Posts: 165
Default Canopy Release

Roger, bummer on the first flight!
When I built my latch, I made sure it was a tight fit when the pin/ rod inserted into the nylon block. I still have to pull a second time to fully latch down. Something to consider when you build another is the extra safety latch lock.
I’d also join your closest EAA chapter that has some RV builders. That’s a resource that’s priceless.
__________________
RV4 Built/flying
repmikebrown@yahoo.com
Mike Brown
Reply With Quote
  #43  
Old 02-18-2020, 07:41 AM
Billvt's Avatar
Billvt Billvt is offline
 
Join Date: Dec 2010
Location: Fairfax, VT
Posts: 66
Default RV-4 Canopy Strap Concern

My RV-4 is 90% done, 90% to go and I am working the canopy.

Question is, what to use for the canopy strap to keep canopy from opening all the way on the ground.

If the need arises to jettison the canopy in flight, seems tp me that a strap that is too strong, like paracord, may not break and the canopy would be dancing around on the right side of the aircraft.

Need something that will break when canopy departs but is strong enough to keep canopy open on the ground without breaking.

What are you folks using????

Bill Morelli - A&P I/A - EAA Tech Counselor
Up North Aviation
CNC Instrument Panel Fabrication
Web www.upnorthaviation.com
E-Mail upnorthaviation@gmail.com
- RV-4 build in progress !!!
Reply With Quote
  #44  
Old 02-18-2020, 08:52 AM
fixnflyguy fixnflyguy is offline
 
Join Date: Jan 2006
Location: Winston-Salem, N.C.
Posts: 1,105
Default My solution and thoughts.

I built my -4 as are you, and I have maintained and inspected many others. No two are alike. Everything from parachute chord to steel chains I have seen. Van did a great job of KISS, and the whole canopy jettison idea is great, however after I flew mine a few hours with a chute, I was pretty sure the conditions I (and a PAX) would need to be in for a bail out where far less a worry than keeping the canopy LATCHED in flight and keeping it open on the ground. I have the standard configuration latch mechanism per plans, along with the additional "knife blade" safety latch. I cant imagine any way to have an accidental blow off with this set-up. I also have a very bright LED on my panel with a micro switch that is illuminated if my latch handle is 1/32" off the latch position. For a hold open, I have a 10-12" gas strut simply connected to the canopy cross former and a simple bracket on the R/H roll bar weldment. It holds it exactly where i want it, dampens the close and isn't in the way. I have it attached with a single bolt and large area washer on each side. I'm certain either the strut would fail or the attachment would rip out in event of an in flight opening, but really no way to prove it. ..Hopefully, you will get yours done soon and join the "flying RV-4" group soon..they are a blast!
__________________
Bill E.
RV-4/N76WE
8A7 / Advance NC
Reply With Quote
  #45  
Old 02-18-2020, 09:19 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 4,152
Default

Quote:
Originally Posted by DeeCee 57 View Post
….the canopy of the -4 opened right after take-off rotate, and fell on the right wing, remaining attached for the remainder of the flight. Pilot lost headset and prescription glasses but not the nerves, and brought the aircraft back to a safe landing….
Quote:
Originally Posted by FinnFlyer View Post
Sequence in my RV-3B: Canopy opened 90 degrees, held by strap, then strap broke and opened 180 degrees and rested on right wing. I remembered "fly the airplane" and added throttle to safely make it around the pattern and land. It's very possible that had I been a cooler pilot and only used enough power to climb and fly the pattern near minimum required airspeed, the canopy would have stayed attached. It only tore off when adding full power and getting above maybe 100 mph….
Question - if the canopy can, if mounted more strongly, remain attached long enough to permit a landing, and if the airplane flies well enough for that, what’s the advantage in having it depart?

If it’s open and the lift force on the canopy will tend to hold it open, and if the airplane remains under control, that sounds better than having it leave. The pilot can still leave if he wants to parachute.

Dave
Reply With Quote
  #46  
Old 02-19-2020, 06:27 AM
FinnFlyer FinnFlyer is offline
 
Join Date: Aug 2018
Location: Bell, FL
Posts: 252
Default Stay attached

Yes, seems it makes sense to have a strong tip-over attachment.

However, at higher speeds I don't know if it could start ripping apart at the hinge and trash around held by the tip-over attachment.

Then why have the "weak" piano hinge riveting?

Perhaps the whole idea comes from fighter jets where you want to get rid of the canopy so you can eject. Not having ejection seats in the RVs, and having tip-over canopies that open widely enough for easy egress while in all flight conditions, that idea may be flawed.

Question would be if there are any uncontrolled flight conditions where the tip-over canopy would not stay open?

I forget, are there any actual cases of egress in flight with a parachute from RVs?

Or any reported flight conditions where the canopy did not stay open?

Without real world data, or some engineer doing computer simulations, I'm beginning to think it's all up in the air

Finn
__________________
RV-4 -- Building
N46AZ RV3-B Mazda 13B EFI -- Bought -- Flying
N993FL RV-3A Mazda 13B NA 575 hours
Reply With Quote
  #47  
Old 02-19-2020, 06:33 AM
Christopher Murphy Christopher Murphy is offline
 
Join Date: Feb 2007
Location: colorado
Posts: 854
Default I think better if it separated?

Watch this video. Not sure if the oscillating was PIO or from the canopy.

I know its not a tandem RV


https://youtu.be/BVTnp6fk7oM
__________________
RV-4 "Mr. Twister"
Pitts S1S "Mexican Red" sold and missed
Mr. Twister Airshows
Rocky Mountain Renegades
the mission... have fun.
Reply With Quote
  #48  
Old 02-19-2020, 07:13 AM
Scott Hersha Scott Hersha is offline
 
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 1,289
Default

Wow!! It looks like his helmet may have saved him.
__________________
SH
RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2016/sold/2017
RV8/2018 built/Sold(sadly)
RV4/bought 2019 Flying
Cincinnati, OH/KHAO
JAN2020
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:58 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.