Author: "Peter Costick" <peter9545@...> Time: Sun Jun 8, 2003 5:35 am PDT Link
Thinking about wings now.
As I write mine are in a truck somewhere in Australia (I like to
think of them thundering across the Nullibor desert in a huge road
train - very Australian!). To digress from the question the reason
they are thundering across the desert is that they were delivered to
Fremantle, Western Australia instead of Melbourne, Victoria.
Apparently someone somewhere thought that Fremantle is in Australia
so it can't be far from me in Wonga Park, near Melbourne. Just a
matter of 2500 miles and five days on the thundering truck. So if you
are in Oz make sure you state your nearest port when ordering - just
a suggestion.
Anyway it's not slowed me down as I have been busy around the house
doing the stuff I put off while building the emp. And reading the
preview plans for the wings, and all the RVators I've got. One thing
I have noticed is that more that a couple of times people say
in 'first flights' that "everything was great but for the usual heavy
left wing" (or similar words) - does anyone know why the left wing is
heavy? Can it be avoided; is it to do with the build or something
extra in the left wing? Or is it just that the builder sits on that
side of the plane :-)
Just wondering....
Author: "Kyle Boatright" <kyle.boatright@...> Time: Sun Jun 8, 2003 2:39 pm PDT Link
Torque... These are little airplanes swinging aggressive prop's with fairly
powerful engines.
KB
----- Original Message -----
From: "Peter Costick" <peter9545@y...>
To: <RV7and7A@yahoogroups.com>
Sent: Sunday, June 08, 2003 5:38 AM
Subject: [RV7Yahoo] What causes "heavy left wing"?
> Thinking about wings now.
>
> As I write mine are in a truck somewhere in Australia (I like to
> think of them thundering across the Nullibor desert in a huge road
> train - very Australian!). To digress from the question the reason
> they are thundering across the desert is that they were delivered to
> Fremantle, Western Australia instead of Melbourne, Victoria.
>
> Apparently someone somewhere thought that Fremantle is in Australia
> so it can't be far from me in Wonga Park, near Melbourne. Just a
> matter of 2500 miles and five days on the thundering truck. So if you
> are in Oz make sure you state your nearest port when ordering - just
> a suggestion.
>
> Anyway it's not slowed me down as I have been busy around the house
> doing the stuff I put off while building the emp. And reading the
> preview plans for the wings, and all the RVators I've got. One thing
> I have noticed is that more that a couple of times people say
> in 'first flights' that "everything was great but for the usual heavy
> left wing" (or similar words) - does anyone know why the left wing is
> heavy? Can it be avoided; is it to do with the build or something
> extra in the left wing? Or is it just that the builder sits on that
> side of the plane :-)
>
> Just wondering....
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Author: "James E. Tyner" <jetyner@...> Time: Sun Jun 8, 2003 6:37 pm PDT Link
Or maybe even a heavy "left pilot"!
Author: Martin Gomez <mlg28@...> Time: Mon Jun 9, 2003 2:50 pm PDT Link
If I had to guess, I'd say it's the reaction to the prop torque. The
engine is twisting the prop clockwise (as seen from the cockpit) so the
prop twists the airplane counterclockwise, or left wing donw.
On Sunday, June 8, 2003, at 05:38 AM, Peter Costick wrote:
>
> in 'first flights' that "everything was great but for the usual heavy
> left wing" (or similar words) - does anyone know why the left wing is
> heavy? Can it be avoided; is it to do with the build or something
> extra in the left wing? Or is it just that the builder sits on that
> side of the plane :-)
>
> Just wondering....
<image.tiff
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
----------------------------------------
Martin Gomez
mlg28@c...
[Non-text portions of this message have been removed]
Author: "Bob Barrow" <barrow@...> Time: Mon Jun 9, 2003 5:41 pm PDT Link
This torque proposition has been put forward by several people but I don't think this is the answer. In reality a prop on an RV is travelling clockwise as viewed from inside the cockpit. It is also subjected to considerable resistance (read force) in the opposite direction due to prop drag. So the inclination of the fuselage roll will also be clockwise. This would suggest a left wing "light" situation.
The analogy is a helicopter. Viewed from the top the rotors spin counter clockwise. If the tail rotor fails, the tail will also spin in a counter clockwise direction (not in the opposite direction).
If the phenomenon of "left wing drop" has any truth to it (and this may be debateable) it might have more to do with propellor gyroscopic precession and with prop air spiralling around the fuselage and applying force to the left side of the vertical stabiliser. Both of these effects can and do cause left yaw. A secondary effect of left yaw is left bank. And if the plane shows an indication of wanting to enter a left bank, then the left wing will start to drop. You might interpret this as having a "heavy" left wing.
If I had to guess, I'd say it's the reaction to the prop torque. The
engine is twisting the prop clockwise (as seen from the cockpit) so the
prop twists the airplane counterclockwise, or left wing donw.
On Sunday, June 8, 2003, at 05:38 AM, Peter Costick wrote:
>
> in 'first flights' that "everything was great but for the usual heavy
> left wing" (or similar words) - does anyone know why the left wing is
> heavy? Can it be avoided; is it to do with the build or something
> extra in the left wing? Or is it just that the builder sits on that
> side of the plane :-)
>
> Just wondering....
[Non-text portions of this message have been removed]
Author: "Greg Hastings" <greg@...> Time: Mon Jun 9, 2003 7:46 pm PDT Link
Sorry, Bob, but I think you have it wrong.
The torque force on the aircraft will indeed be opposite the direction of
the propeller rotation. The same is true for a helicopter and the opposite
rotational forces on the rotor and fuselage.
In a climb under power, there is an additional left yaw force commonly
called P-Factor, which is the result of the increased angle of attack on the
downward traveling prop blade on the right side compared to the upward
traveling blade on the left side (for clockwise rotating engines).
-----Original Message-----
From: Bob Barrow [mailto:barrow@n...]
Sent: Tuesday, June 10, 2003 1:51 AM
To: RV7and7A@yahoogroups.com
Subject: Re: [RV7Yahoo] What causes "heavy left wing"?
This torque proposition has been put forward by several people but I don't
think this is the answer. In reality a prop on an RV is travelling clockwise
as viewed from inside the cockpit. It is also subjected to considerable
resistance (read force) in the opposite direction due to prop drag. So the
inclination of the fuselage roll will also be clockwise. This would suggest
a left wing "light" situation.
The analogy is a helicopter. Viewed from the top the rotors spin counter
clockwise. If the tail rotor fails, the tail will also spin in a counter
clockwise direction (not in the opposite direction).
If the phenomenon of "left wing drop" has any truth to it (and this may be
debateable) it might have more to do with propellor gyroscopic precession
and with prop air spiralling around the fuselage and applying force to the
left side of the vertical stabiliser. Both of these effects can and do cause
left yaw. A secondary effect of left yaw is left bank. And if the plane
shows an indication of wanting to enter a left bank, then the left wing will
start to drop. You might interpret this as having a "heavy" left wing.
If I had to guess, I'd say it's the reaction to the prop torque. The
engine is twisting the prop clockwise (as seen from the cockpit) so the
prop twists the airplane counterclockwise, or left wing donw.
On Sunday, June 8, 2003, at 05:38 AM, Peter Costick wrote:
>
> in 'first flights' that "everything was great but for the usual heavy
> left wing" (or similar words) - does anyone know why the left wing is
> heavy? Can it be avoided; is it to do with the build or something
> extra in the left wing? Or is it just that the builder sits on that
> side of the plane :-)
>
> Just wondering....
[Non-text portions of this message have been removed]
Yahoo! Groups Sponsor
Van's Air Force - World Wide Wing
www.vansaircraft.net
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]
Author: "Kyle Boatright" <kyle.boatright@...> Time: Mon Jun 9, 2003 7:47 pm PDT Link
Bob,
You are mistaken. The torque does cause a left rolling tendancy. Ever
notice those old Navy films where someone stalls a Hellcat or a Corsair on
takeoff or go-around during carrier operations? The torque always rolls
them left. Our props turn the same way as on those aircraft. We just have
an aircraft with 1/10th the horsepower and 1/5 the weight...
KB
----- Original Message -----
From: "Bob Barrow" <barrow@n...>
To: <RV7and7A@yahoogroups.com>
Sent: Tuesday, June 10, 2003 4:50 AM
Subject: Re: [RV7Yahoo] What causes "heavy left wing"?
> This torque proposition has been put forward by several people but I don't
think this is the answer. In reality a prop on an RV is travelling clockwise
as viewed from inside the cockpit. It is also subjected to considerable
resistance (read force) in the opposite direction due to prop drag. So the
inclination of the fuselage roll will also be clockwise. This would suggest
a left wing "light" situation.
>
> The analogy is a helicopter. Viewed from the top the rotors spin counter
clockwise. If the tail rotor fails, the tail will also spin in a counter
clockwise direction (not in the opposite direction).
>
> If the phenomenon of "left wing drop" has any truth to it (and this may be
debateable) it might have more to do with propellor gyroscopic precession
and with prop air spiralling around the fuselage and applying force to the
left side of the vertical stabiliser. Both of these effects can and do cause
left yaw. A secondary effect of left yaw is left bank. And if the plane
shows an indication of wanting to enter a left bank, then the left wing will
start to drop. You might interpret this as having a "heavy" left wing.
> If I had to guess, I'd say it's the reaction to the prop torque. The
> engine is twisting the prop clockwise (as seen from the cockpit) so the
> prop twists the airplane counterclockwise, or left wing donw.
>
> On Sunday, June 8, 2003, at 05:38 AM, Peter Costick wrote:
> >
> > in 'first flights' that "everything was great but for the usual heavy
> > left wing" (or similar words) - does anyone know why the left wing is
> > heavy? Can it be avoided; is it to do with the build or something
> > extra in the left wing? Or is it just that the builder sits on that
> > side of the plane :-)
> >
> > Just wondering....
> [Non-text portions of this message have been removed]
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Author: Jack Loflin <loflinj@...> Time: Mon Jun 9, 2003 7:47 pm PDT Link
Remember the FOUR left turning tendencies in a typical single-engine plane?
Torque, P-Factor, Spiraling slipstream, and precession....I have not mounted
my engine yet, but I'd guess it's got a bit of "right" built into either the
firewall or engine mount. Can anyone confirm this?
Author: Bwana@... Time: Mon Jun 9, 2003 7:48 pm PDT Link
Hi Peter.
I've seen thousands of torque rolls and they all roll opposite the
direction of the engine rotation and quite often when powering up I have
to add hefty right rudder to keep that left wing from dropping (i.e., very
light & high HP). To eliminate torque as a problem just pull the throttle
back to idle. This pretty much minimizes slipstream as well. Holding a
constant (descent) attitude takes care of gyroscopic precession, which
shouldn't be much at idle anyways. What it does at that point should
indicate the engine or not. It'll also be a real good indication of your
alignment. Not sure the term "rigging" applies to an RV. If the left wing
drops make darn sure you can bring it back up with rudder alone. If not,
you'll probably have some serious stability problems as without applying
opposite aileron it'll roll right on over inverted. In that case, contact
Vans.
Bob Buckley
Colorado Springs
> This torque proposition has been put forward by several people but I
don't think this is
the answer. In reality a prop on an RV is travelling clockwise as viewed
from inside the
cockpit. It is also subjected to considerable resistance (read force) in
the opposite
direction due to prop drag. So the inclination of the fuselage roll will
also be
clockwise. This would suggest a left wing "light" situation.
>
> The analogy is a helicopter. Viewed from the top the rotors spin counter
clockwise. If the
tail rotor fails, the tail will also spin in a counter clockwise direction
(not in the
opposite direction).
>
> If the phenomenon of "left wing drop" has any truth to it (and this may
be debateable) it
might have more to do with propellor gyroscopic precession and with prop
air spiralling
around the fuselage and applying force to the left side of the vertical
stabiliser. Both
of these effects can and do cause left yaw. A secondary effect of left yaw
is left bank.
And if the plane shows an indication of wanting to enter a left bank, then
the left wing
will start to drop. You might interpret this as having a "heavy" left wing.
> If I had to guess, I'd say it's the reaction to the prop torque. The
> engine is twisting the prop clockwise (as seen from the cockpit) so
the
> prop twists the airplane counterclockwise, or left wing donw.
>
> On Sunday, June 8, 2003, at 05:38 AM, Peter Costick wrote:
> >
> > in 'first flights' that "everything was great but for the usual heavy
> > left wing" (or similar words) - does anyone know why the left wing is
> > heavy? Can it be avoided; is it to do with the build or something
> > extra in the left wing? Or is it just that the builder sits on that
> > side of the plane :-)
> >
> > Just wondering....
> [Non-text portions of this message have been removed]
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
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Author: "Bob Barrow" <barrow@...> Time: Tue Jun 10, 2003 3:35 am PDT Link
Ok I've taken a battering on this one and I have to come clean and eat humble pie on my "torque" statement. I just checked the FAA Basic Helicopter Handbook and it says: "As the main rotor of a helicopter turns in one direction, the fuselage tends to rotate in the opposite direction". Thanks to Martin Gomez who diplomatically pointed out the error of my assumption at length in a private email.
[Non-text portions of this message have been removed]
Author: "Martin Gomez" <mlg28@...> Time: Tue Jun 10, 2003 7:25 am PDT Link
Bob,
We all join these mail groups to learn. What I've learned in just a
few months of reading will save me many hours of head-scratching time
when I start building. I've stuck my foot in my mouth on more mail
groups than I can count.
I'm going to build an RV-7. I am still debating Quickbuild vs slow
build. My cost spreadsheet estimates $65,000 (US), and I'm sure my
estimate is low...so that may tip me in favor of the slow build.
Regards,
Martin
--- In RV7and7A@yahoogroups.com, "Bob Barrow" <barrow@n...> wrote:
> Ok I've taken a battering on this one and I have to come clean and
eat humble pie on my "torque" statement. I just checked the FAA Basic
Helicopter Handbook and it says: "As the main rotor of a helicopter
turns in one direction, the fuselage tends to rotate in the opposite
direction". Thanks to Martin Gomez who diplomatically pointed out the
error of my assumption at length in a private email.
>
> [Non-text portions of this message have been removed]