Mailing List lml@lancaironline.net Message #50415
From: Bill Kennedy <bill_kennedy_3@hotmail.com>
Sender: <marv@lancaironline.net>
Subject: RE: [LML] Legacy damaged
Date: Wed, 11 Feb 2009 18:01:07 -0500
To: <lml@lancaironline.net>
If your car hood come open at highway speeds, you are in real trouble since it will come all the way open against your windshield. If your forward hinged Lancair canopy unlatches in flight, it opens an inch or so and stays there. If you had two people in the plane, you could probably close it easily, but it'd take an army to force it further open. Do you really need a latch?


To: lml@lancaironline.net
Date: Wed, 11 Feb 2009 13:02:41 -0500
From: wfhannahan@yahoo.com
Subject: [LML] Legacy damaged

2

My thoughts have been running similar to Jim¢s, but rather than make it a checklist item it would be automatic, like the safety catch on a car hood.

 

To enter the plane unlatch the canopy in the usual way, raise it 1-2 inches, slip your fingers under the edge to release the safety catch, open the canopy all the way.

 

During taxi the safety catch would automatically engage, yet allow ventilation. If the pilot takes off the latch would prevent the large excursions, 6-12 inches, which seem to be part of a feedback loop producing the large oscillations.

 

Since it is automatic it is not a checklist item and cannot be forgotten.

 



Regards,
Bill Hannahan


--- On Tue, 2/10/09, Jim Scales <joscales98@hotmail.com> wrote:
From: Jim Scales <joscales98@hotmail.com>
Subject: [LML] Re: Legacy damaged
To: lml@lancaironline.net
Date: Tuesday, February 10, 2009, 11:32 AM

Being an ES flyer I am not really qualified to enter this thread but I will anyway. Just a tinkerer's thoughts.
 
An item for a checklist on the hinged canopy could be "Check Canopy Safety Catch".  It would refer to a safety chain (or cable) very similar to that which is used for security on a door in a hotel. I'm sure the assembly would need to be stronger but the design could be similar, very simple and pretty well fool proof (as long as it is connected, of course).
 
I would think this would control the problem, if the latch releases, by holding the canopy to maximum opening of a couple of inches. No need to attempt to close it. No electronics.  No chance of failure of micro switches, lights or horns.  Very inexpensive.
 
It does not insure that the canopy latches are properly operated but, if the reports of controllability when the canopy pops are correct, it would prevent serious problems and allow the plane to be landed safely.  It would also function in the case of a late canopy release such as in cruise, in which case warning systems would be of little value.
 
If this line of thought has been followed in the past, and found to be a non-solution, I apologize for taking up space.
 
Just a thought.............
 
Jim Scales
 
 
----- Original Message -----
Sent: Monday, February 09, 2009 11:49 PM
Subject: [LML] Legacy damaged

Forget about winch systems, etc. for the canopy. If it comes open in-flight, ignore it and land the plane as soon as practical, close the canopy and go about your business.

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