A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Grob twin II rear canopy hinge release mechanism



 
 
Thread Tools Display Modes
  #1  
Old July 5th 17, 04:22 PM posted to rec.aviation.soaring
mas
external usenet poster
 
Posts: 2
Default Grob twin II rear canopy hinge release mechanism

During flight, the right rear canopy lifted and the passenger used his hands to hold the canopy in the closed position for the rest of the flight (immediate descent). Upon post flight inspection, we noticed the rod has dropped and the lever handle is disconnected. Has this happened before to anyone? We are looking for drawings to see what is behind and how to gain access for the repair.
Any advice?
  #2  
Old July 5th 17, 04:54 PM posted to rec.aviation.soaring
Duster[_2_]
external usenet poster
 
Posts: 198
Default Grob twin II rear canopy hinge release mechanism

Mas,
Yes, coincidentally we reported ours had what appears to be a similar problem with our Grob 103 III exactly one year ago today. Ours was a failure in a 1cm pin that holds the handle fitting with the "bayonet" rods that engage the receiver pin on the gunwale. I replaced the pin, but beware that this pin was worn through by friction with the handle plate. More info if you need.
Mike

From Duster 7-5-16: Our club Grob 103 Twin III canopy lock/unlock mechanism (front seat) failed on the ground when someone tried to open it. Upon close inspection, one of the 2 hidden bolts closest to the handle had gradually been cut through by the lever action to the breaking point. Though we found a way to replace the bolt, we may want to inspect the other bolts in both front and rear canopies. The problem is that the manufacturer glassed in both mechanisms and there does not seem to be a way to effect inspection other than to cut into the frames. Does anyone have a clue as to how to do this? Have there been reports of similar issues with these models? I can't seem to find any AD's on it.

Here are some pictures of the mechanism taken by a Grob owner in Sweden in 2007 of a damaged frame with a window cut out to make repairs:
http://syntaxsociety.se/~wed/flyg/progress.html

Thanks,
Mike

From JJ:
First off, you should report this to the Federallies. The canopy frame can be opened up by carefully cutting a hole in the problem area, then replace the worn / broken bolts, then close it up by gluing in a backing plate which can be a "donut" shape. After the backing plate cures, then glue in a skin replacement (which can be the original piece ) if you were careful when opening up the frame. Fill and paint and she's ready to go. If your not comfortable with any of this, your frame should probably see a sailplane Doctor..
Have fun,
JJ

From Duster:
Your suggestion to report this to the Feds is worth serious consideration, particularly since the locking mechanism cannot be inspected without cutting into the frame. The "catch 22" is a bit rhetorical; what would prompt anyone from creating a window to inspect the thing unless there was already a problem? An A/D? For each Grob of this type, there are 4 bolts to check for each of the 2 canopies. Not much of a problem on the ground, but if you wanted to egress at altitude, the unlocked left side may prevent bailout even though the right-side emergency release worked.
Good thoughts, Thanks.
Mike
  #3  
Old July 5th 17, 06:06 PM posted to rec.aviation.soaring
Duster[_2_]
external usenet poster
 
Posts: 198
Default Grob twin II rear canopy hinge release mechanism

For a schematic see page 7 of the maint manual:
http://www.utahsoaring.org/Documents...20Manual.pd f
 




Thread Tools
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Grob 103 Canopy release failure Duster Soaring 2 July 6th 16 04:58 PM
Grob Twin II Aft Canopy Plexi Bill T Soaring 0 August 31st 14 02:37 AM
GRob 103 TwinII Acro rear canopy Soarin Again[_2_] Soaring 3 May 1st 13 12:00 AM
Twin Astir rear canopy André R Pepin Soaring 0 May 20th 12 03:16 PM
Looking for Grob Twin Astir Gear Retract Mechanism AJM Soaring 0 August 18th 09 05:03 AM


All times are GMT +1. The time now is 09:55 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.