 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
PGLong
Joined: 10 Jan 2006
Posts: 37
|
 Posted: Sun Aug 27, 2006 1:41 pm Post subject: Weight & Balance |
 |
|
After removing the vacuum system, pump and instruments, and adding an autopilot, I want to re-weigh and do a weight & balance on my RV-4. Is it feasable to top off the fuel tanks, assume a 32 gallon load and then reverse the fuel arm and weight to arrive at the gross aircraft weight? Part of my brain says that won't work correctly. Any thoughts?
Pat Long
PGLong(at)aol.com
N120PL
RV4
Bay City, Michigan
3CM
Do Not Archive
[quote][b]
| | - The Matronics RV-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?RV-List |
|
_________________
Pat Long
RV-4, N120PL
Bay City, MI |
|
| Back to top |
|
 |
gyoung
Joined: 09 Jan 2006
Posts: 211
Location: Republic of Texas
|
| Posted: Sun Aug 27, 2006 2:07 pm Post subject: Weight & Balance |
|
|
Sure, it will work. The fuel weight should be obvious but be careful the fuel moment is backed out the correct way. Do a sanity check afterwards to see if adding fuel back in on a pre-flight W&B using your new empty weight and CG gets you back to what showed on the scales.
Greg Young
[quote]
After removing the vacuum system, pump and instruments, and adding an autopilot, I want to re-weigh and do a weight & balance on my RV-4. Is it feasable to top off the fuel tanks, assume a 32 gallon load and then reverse the fuel arm and weight to arrive at the gross aircraft weight? Part of my brain says that won't work correctly. Any thoughts?
Pat Long
PGLong(at)aol.com
N120PL
RV4
Bay City, Michigan
3CM
Do Not Archive
[b]
| | - The Matronics RV-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?RV-List |
|
|
|
| Back to top |
|
|
ronlee(at)pcisys.net
Guest
|
| Posted: Sun Aug 27, 2006 2:20 pm Post subject: Weight & Balance |
|
|
At 03:41 PM 8/27/2006, you wrote:
| Quote: | After removing the vacuum system, pump and instruments, and adding an autopilot, I want to re-weigh and do a weight & balance on my RV-4. Is it feasable to top off the fuel tanks, assume a 32 gallon load and then reverse the fuel arm and weight to arrive at the gross aircraft weight? Part of my brain says that won't work correctly. Any thoughts?
|
If you can weigh it empty then add the weight of 32 gallons at its arm, why not?
Ron Lee
[quote][b]
| | - The Matronics RV-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?RV-List |
|
|
|
| Back to top |
|
|
khorton01(at)rogers.com
Guest
|
| Posted: Sun Aug 27, 2006 2:40 pm Post subject: Weight & Balance |
|
|
On 27 Aug 2006, at 17:41, PGLong(at)aol.com (PGLong(at)aol.com) wrote:
| Quote: | After removing the vacuum system, pump and instruments, and adding an autopilot, I want to re-weigh and do a weight & balance on my RV-4. Is it feasable to top off the fuel tanks, assume a 32 gallon load and then reverse the fuel arm and weight to arrive at the gross aircraft weight? Part of my brain says that won't work correctly. Any thoughts?
Pat Long
PGLong(at)aol.com (PGLong(at)aol.com)
N120PL
RV4
Bay City, Michigan
3CM
|
This will work, if you have already confirmed that you have 32 USG usable fuel load. The number from Van's is only the nominal value. Every aircraft is slightly different.
But, if you subtract the fuel, you'll get an empty weight, not the gross weight, right?
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
[quote][b]
| | - The Matronics RV-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?RV-List |
|
|
|
| Back to top |
|
|
PGLong
Joined: 10 Jan 2006
Posts: 37
|
| Posted: Sun Aug 27, 2006 2:55 pm Post subject: Re: Weight & Balance |
|
|
Right, empty weight. There is just enough grey area, guess I'll wait till I'm light enough on fuel to have storage for the balance. Didn't want to do that, but it is the correct and safer way.
Pat
| | - The Matronics RV-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?RV-List |
|
_________________
Pat Long
RV-4, N120PL
Bay City, MI |
|
| Back to top |
|
|
dreel(at)cox.net
Guest
|
| Posted: Mon Aug 28, 2006 5:47 am Post subject: Weight & Balance |
|
|
When I reweighed my 8A, I drained the fuel tanks by pumping fuel into cans
through a hose connected in place of the carb fuel inlet using the auxiliary
electric fuel pump. This insured the correct amount of unusable fuel
remained in the tanks and eliminated the uncertainty over exactly how much
fuel was in the tanks. If I was off by 1 gallon, 6lb, that would translate
into a moment of 480 for a CG position error of +/- 6 tenths of a percent in
CG location given the empty moment of my airplane, 84575. Not a very big
error as errors go. Still, it made me uncomfortable enough that I took the
slightly harder route of emptying the tanks.
There were two additional benefits to this approach: I could calibrate a
dip stick for measuring usable fuel by refilling the empty tanks in two
gallon increments, and, by raising the gas can above the fuel tank level, I
could look at my see through fuel filter during the pump out operation to
see if the fuel system was sucking any air.
Dave Reel - RV8A
| | - The Matronics RV-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?RV-List |
|
|
|
| Back to top |
|
|
denis.walsh(at)comcast.ne
Guest
|
| Posted: Mon Aug 28, 2006 6:03 am Post subject: Weight & Balance |
|
|
An excellent tip. Thank you.
Such sharing of good building tips is becoming very rare on this
list, so forgive me for further clogging it.
No not archive.
Denis Walsh
On Aug 28, 2006, at 07:49 281700008, DAVID REEL wrote:
| Quote: |
When I reweighed my 8A, I drained the fuel tanks by pumping fuel
into cans
through a hose connected in place of the carb fuel inlet using the
auxiliary
electric fuel pump. This insured the correct amount of unusable fuel
remained in the tanks and eliminated the uncertainty over exactly
how much
fuel was in the tanks. If I was off by 1 gallon, 6lb, that would
translate
into a moment of 480 for a CG position error of +/- 6 tenths of a
percent in
CG location given the empty moment of my airplane, 84575. Not a
very big
error as errors go. Still, it made me uncomfortable enough that I
took the
slightly harder route of emptying the tanks.
There were two additional benefits to this approach: I could
calibrate a
dip stick for measuring usable fuel by refilling the empty tanks in
two
gallon increments, and, by raising the gas can above the fuel tank
level, I
could look at my see through fuel filter during the pump out
operation to
see if the fuel system was sucking any air.
Dave Reel - RV8A
|
| | - The Matronics RV-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?RV-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
