X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 23 Mar 2014 15:12:52 -0400 Message-ID: X-Original-Return-Path: Received: from nm15-vm2.access.bullet.mail.gq1.yahoo.com ([216.39.63.43] verified) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6792267 for lml@lancaironline.net; Sat, 22 Mar 2014 17:40:27 -0400 Received-SPF: none receiver=logan.com; client-ip=216.39.63.43; envelope-from=bbradburry@bellsouth.net Received: from [216.39.60.165] by nm15.access.bullet.mail.gq1.yahoo.com with NNFMP; 22 Mar 2014 21:39:50 -0000 Received: from [98.138.104.97] by tm1.access.bullet.mail.gq1.yahoo.com with NNFMP; 22 Mar 2014 21:39:50 -0000 Received: from [127.0.0.1] by smtp117.sbc.mail.ne1.yahoo.com with NNFMP; 22 Mar 2014 21:39:50 -0000 X-Yahoo-Newman-Id: 84394.95629.bm@smtp117.sbc.mail.ne1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: PJSMf7kVM1lF51aGUhSghotgZzpeD9gSfbzGnpLt4mpsFme m8aNdQaiNfWgc17Kpux_q4GoIjFl6RDUmD8Y25DjY.ImsGibNUf6H2OQld3J eeeSNOmFG07TwdHGnlZozbEInIJPK.BNvYuKGTzj8ee1in4atgNrBCggD4n8 YTUqly_Wd8HVQItzexU.TuYgjeF.I8TrmUbzy8vhCfDECvJR0lkefe9dbqgj nmfzQEPdCjkZn22QfUc_.S.aO3skY9EL3SPW2IWarIewQplaQJns6mafSKyO qLQQ9Fi4LDbzq3mfcR3c08i8NDxLa.PVDYVQlVIlln6YeF.uxemx.NQ0Q4yd kJTmcL59ZBOXUxKXohfoXMxGhb76zRMKEsr4R6UUnMghSO5pzRjn_t0fbzUz 118_VUe55JiejoeBQ3d7ksa2RGuhMqDetYettigzca8ZYKfNbEi1QWRncJGp fEvVHgKFpXG7GURuXOvsXQxuC_DXlSSpa1HI6OEDJvdAjkMte3H6LVHUzAh8 OnwddODiCodQCkH8UPE00arUyW59IkZfqGxaKy_u7ltx36HkeGHJv X-Yahoo-SMTP: gncFbbmswBBF8NfvI5ui22IxJJ5CCB4H6ZgiimJia8BbGK2EyA-- X-Rocket-Received: from [10.6.18.214] (bbradburry@50.84.165.35 with plain [98.138.84.52]) by smtp117.sbc.mail.ne1.yahoo.com with SMTP; 22 Mar 2014 21:39:50 +0000 UTC X-Original-Message-ID: <532E0326.7060505@bellsouth.net> X-Original-Date: Sat, 22 Mar 2014 16:39:50 -0500 From: Bill Bradburry User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 X-Original-To: Lancair Mailing List Subject: Re: [LML] Back up canopy latch requirements References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------040705010202090806000400" This is a multi-part message in MIME format. --------------040705010202090806000400 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit It seems that some design rule ideas could be posited.. If the canopy is lowered to within 2-3 inches of closed, the secondary latch will engage and hold the canopy open in that position for ventilation and with enough force that the canopy will not open further if takeoff is made with it in that position. The secondary latch can easily be manipulated to bring the canopy to a fully closed position where the main latch can be engaged. The secondary latch can easily be manipulated to release the canopy to raise it after the main latch is disengaged. Other ideas as you like.... Bill B On 3/6/2014 7:05 AM, frederickemoreno@gmail.com wrote: > "Questions for the latch designers: > Will the secondary latch engage automatically on closing the canopy? > If not then you're adding to the checklist. > "How far will you have to close the canopy for the secondary latch to > engage? > I see limited efficacy if you have to close it farther than the point > People prop open their canopy for ground ventilation. > ""Will the secondary latch be operated by the primary lock handle? > This would be ideal. > Can the secondary latch be released from outside the cockpit and will its > Operation be obvious? > In my mind, the answers to these questions are critical. I won't use a > Latch that doesn't allow immediate and obvious ingress in an emergency." > These requirements and more were on the initial requirements list. > Working with a small team, John Smith has compiled about 25 different > ideas and variants. Most focus on requirements first, then > simplicity, then means of attachment. General approach: > > * Latch is on top of canopy with simple striker plate on fuselage arch > * It latches while the canopy is still open a bit but latches into > place when you release canopy you are holding open with your hand. > * Pilot or copilot applies single upward motion to lift canopy at > center with upward facing palm of hand applied to a small forward > facing lever that disengages latch when you push up. So getting > out is 1) release main latch and 2) reach up, push up on canopy at > center which means your palm will push up on the internal lever, > and canopy opens. > * A penetration through the arch to the outside engages a flush or > nearly flush lever outside on top that can be pulled up from > outside. Rescuer approaches plane, side latch is released, canopy > can be raised an inch or two, hits secondary latch, but external > lever is clearly visible to untrained outsider who can immediately > detect what is still holding the canopy from further motion, sees > the lever, pulls up on lever, canopy does its final release and > swings upward. Think of it as similar to a hood latch that has > its release on the top surface of the hood. > > Other requirements (must haves) and desires (nice to have) welcome. > John is a very busy boy, on the road a lot, so I am providing first > response, but he is the leader of the team working this problem in > Australia. Current questions focus on attachment methods to canopy > and fuselage arch, and have been submitted to Lancair. With some > guidance on approved attachment methods and locations, we can narrow > the options and present to this group for review. > Fred Moreno > > > --------------040705010202090806000400 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit It seems that some design rule ideas could be posited..

If the canopy is lowered to within 2-3 inches of closed, the secondary latch will engage and hold the canopy open in that position for ventilation and with enough force that the canopy will not open further if takeoff is made with it in that position.

The secondary latch can easily be manipulated to bring the canopy to a fully closed position where the main latch can be engaged.

The secondary latch can easily be manipulated to release the canopy to raise it after the main latch is disengaged.

Other ideas as you like....

Bill B
On 3/6/2014 7:05 AM, frederickemoreno@gmail.com wrote:
"Questions for the latch designers:
 
Will the secondary latch engage automatically on closing the canopy?
If not then you're adding to the checklist.
 
"How far will you have to close the canopy for the secondary latch to engage?
I see limited efficacy if you have to close it farther than the point
People prop open their canopy for ground ventilation.
 
""Will the secondary latch be operated by the primary lock handle?
This would be ideal.
 
Can the secondary latch be released from outside the cockpit and will its
Operation be obvious?
In my mind, the answers to these questions are critical. I won't use a
Latch that doesn't allow immediate and obvious ingress in an emergency."
 
 
These requirements and more were on the initial requirements list.  Working with a small team, John Smith has compiled about 25 different ideas and variants.  Most focus on requirements first, then simplicity, then means of attachment. General approach:
  • Latch is on top of canopy with simple striker plate on fuselage arch
  • It latches while the canopy is still open a bit but latches into place when you release canopy you are holding open with your hand.
  • Pilot or copilot applies single upward motion to lift canopy at center with upward facing palm of hand applied to a small forward facing lever that disengages latch when you push up. So getting out is 1) release main latch and 2) reach up, push up on canopy at center which  means your palm will push up on the internal lever, and canopy opens.
  • A penetration through the arch to the outside engages a flush or nearly flush lever outside on top that can be pulled up from outside.  Rescuer approaches plane, side latch is released, canopy can be raised an inch or two, hits secondary latch, but external lever is clearly visible to untrained outsider who can immediately detect what is still holding the canopy from further motion, sees the lever, pulls up on lever, canopy does its final release and swings upward.  Think of it as similar to a hood latch that has its release on the top surface of the hood.
Other requirements (must haves) and desires (nice to have) welcome.  John is a very busy boy, on the road a lot, so I am providing first response, but he is the leader of the team working this problem in Australia.   Current questions focus on attachment methods to canopy and fuselage arch, and have been submitted to Lancair.   With some guidance on approved attachment methods and locations, we can narrow the options and present to this group for review.
 
Fred Moreno



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