 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Dave(at)AirCraftersLLC.co
Guest
|
 Posted: Thu Jul 24, 2008 4:34 pm Post subject: Cabin Roof |
 |
|
My sense is that the top is very strong.
I had a discussion with the factory, the upshot of which was that Engineering was concerned about (prohibited) drilling the 2 #10 holes in the rain channel for the visor mounts. Rather than thinking "jeez, it won't even take a couple little holes", the proper thought should be that some parts are critical and should not be casually modified. Those channels were designed from the beginning to be strong enough to protect the occupants.
I know the upper roof section is VERY thick for a fiberglass piece. Again, that is for a reason (added strength), not because it was easy or cheap. The core is pretty dense too, adding to the strength.
The cage formed by the door frames and roof looks pretty strong. Everything has a limit, but the roof doesn't seem to me at all like a weak point.
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
831-750-0284 CL
www.AirCraftersLLC.com
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Ben Westfall
Sent: Thursday, July 24, 2008 2:00 PM
To: rv10-list(at)matronics.com
Subject: RE: Sb 08-6-1
John,
I asked Van about the cabin top strength directly. He said that they drop tested a fuselage and the top help up. I did not ask him any more specifics as to the drop test except that I asked if the windows blew out or cracked but he didn’t remember.
I myself don’t know a single thing about fiberglass strengths so I don’t even have an opinion as to the cabin top strength. I’m curios why the impression is that the top is a “questionable structural component”. Does anyone know for certain its strengths/weaknesses or are we all just aluminum bigots and we think fiberglass is weak? I’m not picking on anyone I just want to know why the consensus seems to be that the top is not strong enough. It looks thicker and stronger than any glass plane I’ve looked at.
-Ben W
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of John Jessen
Sent: Thursday, July 24, 2008 7:45 AM
To: rv10-list(at)matronics.com
Subject: RE: Sb 08-6-1
Dave actually has an interesting and worthy point. It's not so much about the SB, I think, as about some of the engineering decisions. The plane is a good airplane, and certainly every plane design has some unforeseen issues that must be field addressed. That's no problem. It's also not about how big or small the pieces are, since some very small pieces in this plane serve very important functions...think cotter pins.
However, there are more than a few design issues that leave one scratching the bald spot. Doors that rip off when accidentally opening in flight (it will happen many times within any fleet of planes, not just the RV-10, and give the flex within the cabin and doors, should have been an anticipated event leading to a more airworthy design), almost certainly causing HS damage in the process. Too few ribs in the HS to sustain bird (or door strikes). An odd "discontinuity" in the trim tabs for some unknown reason (at least to me, is this a means of addressing a problem in handling at low, high power speeds?) not actually understood that might be contributing to what stresses. Doors that do not have a second safety catch, especially given their lack of aerodynamics when opened in flight. Brakes that are not vented and of a mass that is correspondent to the size and possible uses of the plane. A lack of a cage or simple roll bar to augment what is a questionable structural component of the fuselage, namely the fiberglass top. Brake master cylinders that stick out so feet can hit them, possibly causing some type of leak (I've never understood this in all of Van's planes) There are more, I'm sure.
Tim James has a -10 with a roll bar, as well as a two-stop door catch, both easy fixes to the current design. Paul Grimstad has developed a sensible (and beautiful) rudder pedal and brake assembly replacement. We're waiting for a truly structural cabin top, but a roll bar would suffice. The innovators are out there addressing the shortcomings, which will be identified as we move forward. Eventually they will be addressed, one at a time, leading to a better platform, but being addressed by the builder community. Someone will come up with better doors, I'm sure. I hope. Maybe a whole replacement for cabin top and doors.
Back to Dave's point. I think we need to evaluate each issue and address them, one by one, as a flying community. We need to question each and every one, which, by his question, Dave does. It's not an insurance issue. His question was to shine a questioning light on a design issue. Is there something else going on here that we need to understand, and does this replacement part fix the inherent problem or is it a band-aid? Yes, the fact that a piece was sent out to all registered users indicates a serious problem, and we all are happy that the problem was caught and a quick response came forth. What about the others? I find the door issue one of a nature that should not have to be addressed by each builder alone, nor by the builder community, but by the engineers at Van's.
My plea is that, if a builder finds something or knows of something, that it be shared with all, especially if they have come up with a fix! I'll try to get good pictures of Tim's roll bar and double catch door latch, and perhaps whatever measurements are needed, along with a parts list for posting. If you're using this list while building but do not contribute ideas and discussions, please think about starting to do so. There aren't that many who take the time to post; we need everyone's help and good ideas.
Thanks, Dave, for having the courage to open this thread. And, thanks to all for their sincere, non-flammable replies. A great community.
Have fun at OSH. Take lots of pictures! Share!
John J [quote]
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Dave Leikam
Sent: Wednesday, July 23, 2008 8:59 PM
To: rv10-list(at)matronics.com
Subject: Re: Sb 08-6-1
With all due respect, I know I have to do the SB, and I will, but if the empennage is that inclined to come off this airplane without those two small pieces of aluminum installed, I wouldn't fly it after they were installed!
Dave Leikam
RV-10 #40496
N89DA (Reserved)
Muskego, WI
do not archive
[quote]
---
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
 |
n212pj(at)gmail.com
Guest
|
| Posted: Fri Jul 25, 2008 7:04 am Post subject: Cabin Roof |
|
|
Thanks, Ben and Dave, good responses. Makes me feel much better.
John
[quote] From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Dave Saylor
Sent: Thursday, July 24, 2008 5:29 PM
To: rv10-list(at)matronics.com
Subject: Cabin Roof
My sense is that the top is very strong.
I had a discussion with the factory, the upshot of which was that Engineering was concerned about (prohibited) drilling the 2 #10 holes in the rain channel for the visor mounts. Rather than thinking "jeez, it won't even take a couple little holes", the proper thought should be that some parts are critical and should not be casually modified. Those channels were designed from the beginning to be strong enough to protect the occupants.
I know the upper roof section is VERY thick for a fiberglass piece. Again, that is for a reason (added strength), not because it was easy or cheap. The core is pretty dense too, adding to the strength.
The cage formed by the door frames and roof looks pretty strong. Everything has a limit, but the roof doesn't seem to me at all like a weak point.
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
831-750-0284 CL
www.AirCraftersLLC.com
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Ben Westfall
Sent: Thursday, July 24, 2008 2:00 PM
To: rv10-list(at)matronics.com
Subject: RE: Sb 08-6-1
John,
I asked Van about the cabin top strength directly. He said that they drop tested a fuselage and the top help up. I did not ask him any more specifics as to the drop test except that I asked if the windows blew out or cracked but he didn’t remember.
I myself don’t know a single thing about fiberglass strengths so I don’t even have an opinion as to the cabin top strength. I’m curios why the impression is that the top is a “questionable structural component”. Does anyone know for certain its strengths/weaknesses or are we all just aluminum bigots and we think fiberglass is weak? I’m not picking on anyone I just want to know why the consensus seems to be that the top is not strong enough. It looks thicker and stronger than any glass plane I’ve looked at.
-Ben W
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of John Jessen
Sent: Thursday, July 24, 2008 7:45 AM
To: rv10-list(at)matronics.com
Subject: RE: Sb 08-6-1
Dave actually has an interesting and worthy point. It's not so much about the SB, I think, as about some of the engineering decisions. The plane is a good airplane, and certainly every plane design has some unforeseen issues that must be field addressed. That's no problem. It's also not about how big or small the pieces are, since some very small pieces in this plane serve very important functions...think cotter pins.
However, there are more than a few design issues that leave one scratching the bald spot. Doors that rip off when accidentally opening in flight (it will happen many times within any fleet of planes, not just the RV-10, and give the flex within the cabin and doors, should have been an anticipated event leading to a more airworthy design), almost certainly causing HS damage in the process. Too few ribs in the HS to sustain bird (or door strikes). An odd "discontinuity" in the trim tabs for some unknown reason (at least to me, is this a means of addressing a problem in handling at low, high power speeds?) not actually understood that might be contributing to what stresses. Doors that do not have a second safety catch, especially given their lack of aerodynamics when opened in flight. Brakes that are not vented and of a mass that is correspondent to the size and possible uses of the plane. A lack of a cage or simple roll bar to augment what is a questionable structural component of the fuselage, namely the fiberglass top. Brake master cylinders that stick out so feet can hit them, possibly causing some type of leak (I've never understood this in all of Van's planes) There are more, I'm sure.
Tim James has a -10 with a roll bar, as well as a two-stop door catch, both easy fixes to the current design. Paul Grimstad has developed a sensible (and beautiful) rudder pedal and brake assembly replacement. We're waiting for a truly structural cabin top, but a roll bar would suffice. The innovators are out there addressing the shortcomings, which will be identified as we move forward. Eventually they will be addressed, one at a time, leading to a better platform, but being addressed by the builder community. Someone will come up with better doors, I'm sure. I hope. Maybe a whole replacement for cabin top and doors.
Back to Dave's point. I think we need to evaluate each issue and address them, one by one, as a flying community. We need to question each and every one, which, by his question, Dave does. It's not an insurance issue. His question was to shine a questioning light on a design issue. Is there something else going on here that we need to understand, and does this replacement part fix the inherent problem or is it a band-aid? Yes, the fact that a piece was sent out to all registered users indicates a serious problem, and we all are happy that the problem was caught and a quick response came forth. What about the others? I find the door issue one of a nature that should not have to be addressed by each builder alone, nor by the builder community, but by the engineers at Van's.
My plea is that, if a builder finds something or knows of something, that it be shared with all, especially if they have come up with a fix! I'll try to get good pictures of Tim's roll bar and double catch door latch, and perhaps whatever measurements are needed, along with a parts list for posting. If you're using this list while building but do not contribute ideas and discussions, please think about starting to do so. There aren't that many who take the time to post; we need everyone's help and good ideas.
Thanks, Dave, for having the courage to open this thread. And, thanks to all for their sincere, non-flammable replies. A great community.
Have fun at OSH. Take lots of pictures! Share!
John J [quote]
From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Dave Leikam
Sent: Wednesday, July 23, 2008 8:59 PM
To: rv10-list(at)matronics.com
Subject: Re: Sb 08-6-1
With all due respect, I know I have to do the SB, and I will, but if the empennage is that inclined to come off this airplane without those two small pieces of aluminum installed, I wouldn't fly it after they were installed!
Dave Leikam
RV-10 #40496
N89DA (Reserved)
Muskego, WI
do not archive
[quote]
---
| | - The Matronics RV10-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?RV10-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
