 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Don G
Joined: 10 Jan 2006
Posts: 156
Location: Central Illinois
|
 Posted: Mon Jun 07, 2010 6:19 am Post subject: Weight and balance..AOA? |
 |
|
Gents,
I decided to do an updated W&B on my 912 powered Speedster, and have discovered an aft cg situation...however..upon thinking of over somewhat, I am not sure I believe it. The plane flies fine. I actually was concerned about the empty weight..which is why I weighed it.
My question, is in regards to the angle you should weigh this aircraft. do you weigh with the wing at "0" degrees to the horizon?..in other words...wings perfectly level fore and aft...or in a flight attitude...which may be a degree or 2 of attack?
I simply raised the tail to an approximate flight atitude by sight, without putting a level on the wings, and I am concerned now Maybe I should have payed more attention to this angle.
Tailwheel weight was 60.25 lbs.....total 697. ONly fuel in the header tank behind the seat.
thx
| | - The Matronics Kitfox-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?Kitfox-List |
|
_________________
Don G.
Central Illinois
Kitfox IV Speedster
Luscombe 8A
RV9A |
|
| Back to top |
|
 |
gebuchanan(at)cox.net
Guest
|
| Posted: Mon Jun 07, 2010 7:41 am Post subject: Weight and balance..AOA? |
|
|
At 07:19 AM 6/7/2010, you wrote:
| Quote: | My question, is in regards to the angle you should weigh this
aircraft. do you weigh with the wing at "0" degrees to the
horizon?..in other words...wings perfectly level fore and aft...or
in a flight attitude...which may be a degree or 2 of attack?
|
Don,
The CG was designed to be measured with the door sill level.
This puts the wings at some positive angle of attack, but I don't
know what that is. What was your CG measurement? Mine regularly runs
15 - 16" aft of the leading edge.
Guy Buchanan
San Diego, CA
K-IV 1200 / 582-C / Warp / 500 hrs. and counting
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
|
sdemeyer
Joined: 31 Jul 2009
Posts: 45
|
| Posted: Mon Jun 07, 2010 7:52 am Post subject: Weight and balance..AOA? |
|
|
Don, I believe the proper method, at least on my IV is to level the fuselage fore/aft and side to side. This is done by placing a level underneath, just behind the landing gear. Then weigh each wheel and go from there. From my experience, it does not take much to really throw off the weight on your tailwheel.
--- On Mon, 6/7/10, Don G <donghe(at)one-eleven.net> wrote:
| Quote: |
From: Don G <donghe(at)one-eleven.net>
Subject: Weight and balance..AOA?
To: kitfox-list(at)matronics.com
Date: Monday, June 7, 2010, 7:19 AM
--> Kitfox-List message posted by: "Don G" <[url=/mc/compose?to=donghe(at)one-eleven.net]donghe(at)one-eleven.net[/url]>
Gents,
I decided to do an updated W&B on my 912 powered Speedster, and have discovered an aft cg situation...however..upon thinking of over somewhat, I am not sure I believe it. The plane flies fine. I actually was concerned about the empty weight..which is why I weighed it.
My question, is in regards to the angle you should weigh this aircraft. do you weigh with the wing at "0" degrees to the horizon?..in other words...wings perfectly level fore and aft...or in a flight attitude...which may be a degree or 2 of attack?
I simply raised the tail to an approximate flight atitude by sight, without putting a level on the wings, and I am concerned now Maybe I should have payed more attention to this angle.
Tailwheel weight was 60.25 lbs.....total 697. ONly fuel in the header tank behind the seat.
thx
--------
Don G.
Central Illinois
Kitfox IV Speedster
Luscombe 8A
Read this topic online here:
http://forums.matronics.com/viewf="http://www.matronics.com/Navigator?Kitfox-List" target="_blank">http - MATRONICS WEB FORUMS ; -Matt Dralle, List Admin==========
|
[quote][b]
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
|
Don G
Joined: 10 Jan 2006
Posts: 156
Location: Central Illinois
|
| Posted: Mon Jun 07, 2010 10:21 am Post subject: Re: Weight and balance..AOA? |
|
|
Ah ha...level at the door sill...got it...Didn't know that! I have no idea what it was..as I said...I just looked around and grabbed whatever stuff was around and put under the tailwheel to get it "about flight attitude..by eye only..I was mostly concerned with what changes might have taken place since I changed out the gear to Groves for my gross weight
using the exell spreadsheet
Cg empty is 15.16 aft...as I weighed it.
add me and no fuel.....16.01
me and full fuel..........16.09
...it goes aft to 16.40 with full fuel and 2 passengers to equal gross of 1250...(dont think I have ever flown it this way) generally..my wife and I and about 20 gallons are under 1200lbs
Looks like for my piece of mind...not to mention an accurate new w&b Sheet..I am going to do it again and this time put a level on it...
thx men!..
| | - The Matronics Kitfox-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?Kitfox-List |
|
_________________
Don G.
Central Illinois
Kitfox IV Speedster
Luscombe 8A
RV9A |
|
| Back to top |
|
|
Lynn Matteson
Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan
|
| Posted: Mon Jun 07, 2010 10:42 am Post subject: Weight and balance..AOA? |
|
|
My Speedster w/Jabiru engine (4 cyl) weighed 650, with 43 lbs of that
weight on the rear wheel, and NO fuel anywhere. So you have 47 lbs
more overall weight, with 17.25 lbs of that at the rear
wheel...roughly 1/3 of the difference between the two weights. Unless
I'm wrong in comparing things this way, the tail weight being 1/3 of
the "overall" weight is way too much. And I don't think the 6-8 lbs
of fuel (I'm guessing at the size of your header tank) that close to
the main wheels will throw the tail weight that high. How are my
backyard, shade tree, calculations, Guy?
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 968.4 hrs (since 3-27-2006)
Countdown to 1000 hrs~31.6 to go(47 days to go)
Sensenich 62"x46" Wood (summer)
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying (and learning)
On Jun 7, 2010, at 11:52 AM, Scott DeMeyer wrote:
| Quote: | Don, I believe the proper method, at least on my IV is to level the
fuselage fore/aft and side to side. This is done by placing a level
underneath, just behind the landing gear. Then weigh each wheel and
go from there. From my experience, it does not take much to really
throw off the weight on your tailwheel.
--- On Mon, 6/7/10, Don G <donghe(at)one-eleven.net> wrote:
From: Don G <donghe(at)one-eleven.net>
Subject: Weight and balance..AOA?
To: kitfox-list(at)matronics.com
Date: Monday, June 7, 2010, 7:19 AM
Gents,
I decided to do an updated W&B on my 912 powered Speedster, and
have discovered an aft cg situation...however..upon thinking of
over somewhat, I am not sure I believe it. The plane flies fine. I
actually was concerned about the empty weight..which is why I
weighed it.
My question, is in regards to the angle you should weigh this
aircraft. do you weigh with the wing at "0" degrees to the
horizon?..in other words...wings perfectly level fore and aft...or
in a flight attitude...which may be a degree or 2 of attack?
I simply raised the tail to an approximate flight atitude by sight,
without putting a level on the wings, and I am concerned now Maybe
I should have payed more attention to this angle.
Tailwheel weight was 60.25 lbs.....total 697. ONly fuel in the
header tank behind the seat.
thx
--------
Don G.
Central Illinois
Kitfox IV Speedster
Luscombe 8A
Read this topic online here:
http://forums.matronics.com/viewf="http://www.matronics.com/
Navigator?Kitfox-List" target="_blank">http - MATRONICS WEB
FORUMS ; -Matt Dralle, List Admin==========
www.matronics.com/contribution _-
============================================================
|
| | - The Matronics Kitfox-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?Kitfox-List |
|
_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM |
|
| Back to top |
|
|
lcfitt(at)sbcglobal.net
Guest
|
| Posted: Mon Jun 07, 2010 10:44 am Post subject: Weight and balance..AOA? |
|
|
Don,
The airplane should be leveled fore and aft and side to side using the belly
tubes below the cockpit or the bottom door sills. With the airplane in this
position, the weights of the mains and tailwheel would give the wts. needed
to calculate the CG.
Lowell
--------------------------------------------------
From: "Don G" <donghe(at)one-eleven.net>
Sent: Monday, June 07, 2010 7:19 AM
To: <kitfox-list(at)matronics.com>
Subject: Weight and balance..AOA?
| Quote: |
Gents,
I decided to do an updated W&B on my 912 powered Speedster, and have
discovered an aft cg situation...however..upon thinking of over somewhat,
I am not sure I believe it. The plane flies fine. I actually was concerned
about the empty weight..which is why I weighed it.
My question, is in regards to the angle you should weigh this aircraft. do
you weigh with the wing at "0" degrees to the horizon?..in other
words...wings perfectly level fore and aft...or in a flight
attitude...which may be a degree or 2 of attack?
I simply raised the tail to an approximate flight atitude by sight,
without putting a level on the wings, and I am concerned now Maybe I
should have payed more attention to this angle.
Tailwheel weight was 60.25 lbs.....total 697. ONly fuel in the header
tank behind the seat.
thx
--------
Don G.
Central Illinois
Kitfox IV Speedster
Luscombe 8A
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=300332#300332
|
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
|
gebuchanan(at)cox.net
Guest
|
| Posted: Mon Jun 07, 2010 11:26 am Post subject: Weight and balance..AOA? |
|
|
At 11:34 AM 6/7/2010, you wrote:
| Quote: | Unless
I'm wrong in comparing things this way, the tail weight being 1/3 of
the "overall" weight is way too much. And I don't think the 6-8 lbs
of fuel (I'm guessing at the size of your header tank) that close to
the main wheels will throw the tail weight that high. How are my
backyard, shade tree, calculations, Guy?
|
Almost Lynn,
Don's tail weight was 8.7% of total, not 1/3. Your's was
6.6%, so yes, Don will probably want to re-level the plane more
expertly. The angle makes a significant difference in "tailwheel
weight", since the wheels are so close to the CG. Indeed, if you tilt
far enough forward you can make the "tailwheel weight" zero! (Don't
try this with the engine running, though.) 
Guy Buchanan
San Diego, CA
K-IV 1200 / 582-C / Warp / 500 hrs. and counting
| | - The Matronics Kitfox-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?Kitfox-List |
|
|
|
| Back to top |
|
|
Lynn Matteson
Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan
|
| Posted: Mon Jun 07, 2010 1:24 pm Post subject: Weight and balance..AOA? |
|
|
Guy-
What I was trying to compare was his tailwheel weight in comparison
to his amount of weight that exceeded my weight. His total weight is
+47 (over mine), of which 17 (more than mine) is at the rear. I was
just trying to give a rough example of how comparing the "overages"
could show how he is tail heavy. The bottom line of course, is that
the plane must be level, or all the math in the world won't help. : )
I landed the other day with just about "zero tailwheel weight",
thanks to those Matco brakes. Next time I'll slow a bit more on
approach. I thought I was gonna loop it when I finally turned about
20 feet from the road, at a pretty good clip. Thanks also to my Grove
gear for putting up with a sharp turn. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 968.8 hrs (since 3-27-2006)
Countdown to 1000 hrs~31.2 to go(47 days to go)
Sensenich 62"x46" Wood (summer)
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying (and learning)
do not archive
On Jun 7, 2010, at 3:24 PM, Guy Buchanan wrote:
| Quote: |
At 11:34 AM 6/7/2010, you wrote:
> Unless
> I'm wrong in comparing things this way, the tail weight being 1/3 of
> the "overall" weight is way too much. And I don't think the 6-8 lbs
> of fuel (I'm guessing at the size of your header tank) that close to
> the main wheels will throw the tail weight that high. How are my
> backyard, shade tree, calculations, Guy?
Almost Lynn,
Don's tail weight was 8.7% of total, not 1/3. Your's was
6.6%, so yes, Don will probably want to re-level the plane more
expertly. The angle makes a significant difference in "tailwheel
weight", since the wheels are so close to the CG. Indeed, if you
tilt far enough forward you can make the "tailwheel weight" zero!
(Don't try this with the engine running, though.)
Guy Buchanan
San Diego, CA
K-IV 1200 / 582-C / Warp / 500 hrs. and counting
|
| | - The Matronics Kitfox-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?Kitfox-List |
|
_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM |
|
| Back to top |
|
|
akflyer
Joined: 07 May 2007
Posts: 574
Location: Soldotna AK
|
| Posted: Mon Jun 07, 2010 3:03 pm Post subject: Re: Weight and balance..AOA? |
|
|
if the KF IV is anything like the Avid, you can run the CG back to 18 or 19" and it will fly better.. Dean Wilson did not recommend stalling without full flaps at CG's aft of 21". This was per a phone conversations with him last year when I was trying to get rid of some of my up trim on the elevator.
| | - The Matronics Kitfox-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?Kitfox-List |
|
_________________
DO NOT ARCHIVE
Leonard Perry aka SNAKE
Soldotna AK
Avid "C" / Mk IV
582 (147 hrs and counting on the rebuild)
IVO IFA
Full Lotus 1450
#1 snake oil salesman since 1-22-2009
I would rather die trying to live, than to live trying not to die.... |
|
| 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
