Forums » Air Combat & Civil Aviation » Rise of Flight - The First Great Air War » Why use Rudder in an established Turn?


Page 1 of 4 1 2 3 4 >
Topic Options
Rate This Topic
Hop to:
#2892261 - 11/01/09 09:35 AM Why use Rudder in an established Turn?
pakfront Offline
Ground Looper
Member

Registered: 04/17/08
Posts: 264
Loc: Crissy Field, CA, USA
Why do planes from this period need so much rudder applied in an established turn?

My (possibly incorrect) understanding of an coordinated turn in the 'ideal' plane is:
1) Use aileron and rudder into the direction of the turn until roll angle is established. Ease in elevator at the same time.

2)Once roll angle is established, center ailerons and rudder. Use elevator to adjust nose angle above/below horizon in order to control altitude gain during turn.

3)As desired heading is reached, ease in opposite (high) aileron and rudder and ease out elevator. This will bring you back to level flight.

I notice that in all RoF planes I have flown so far I feel I need to apply low side rudder to control nose attitude during step 2, established turn. Elevator is not enough. Without rudder the nose wanders high and into a stall. A single wing stall I think, thus leading to a spin. The severity varies by plane, but it seems to be in all of them.

So... are my assumptions about ideal flight correct?
If so, why do these crates differ so strongly from ideal?

Thanks!


Edited by pakfront (11/01/09 10:21 AM)
_________________________
. A pig that doesn't fly is just a pig. - Porco Rosso
. Windows XP Pro SP3, Intel Core 2 Duo E8400 3ghz, 2GB RAM
. GeForce 560 (190.62) 640mb @ 1920x1200 32bpp 96dpi
. TrackIR 3 Vector, Logitech G940 & G25

Top
#2892286 - 11/01/09 10:05 AM Re: Why use Rudder in an established Turn? [Re: pakfront]
Rama Online   content
Member

Registered: 11/22/05
Posts: 583
Loc: Toulouse France
Originally Posted By: pakfront

So... are my assumptions about ideal flight correct?
If so, why do these crates differ so strongly from ideal?


About ideal flight with correctly centered planes, you're right...
... but most of WWI biplanes were heavy back centered, which oblige you tu use elevator constantly in level flight, and rudder while inclined in a turn, to keep the nose level.

Moreover (but isn't really represented in this sim, since you can't control Joystick stiffness), a lot of these crates were also aileron heavy... and inclination was obtained and controlled more with rudder induced roll than ailerons.

Top
#2892337 - 11/01/09 11:53 AM Re: Why use Rudder in an established Turn? [Re: Rama]
Dart Offline
Contributing Editor
Just upgraded from intern
Veteran

Registered: 09/02/01
Posts: 16447
Loc: Alabaster, AL USA
Yo, that's because that's how we rolled back in the day, dawg!

Seriously.

Especially in the case of the powerful rotaries some planes used, the normal twist put on the plane by the motor and prop induced a lot of inherent roll on flight.

So one could either roll towards a turn with the ailerons and then compensated for the additional roll from the engine with the rudder (which is what I'm trying desperately to unlearn in the Camel), which is a game of catch-up, or simply work the roll with the rudder (and keeping the engine torque/progression/whichever in check) and then fine tune with the ailerons.

The latter works best with these crates and their abusive engines and off-of-centers of gravity.

And yeah, they actually wanted this design setup, as it gave the best controllable instability (which is the hallmark of fighter planes) using the materials at hand.
_________________________
The opinions of this poster are largely based on facts and portray a possible version of the actual events.

More dumb stuff at http://www.darts-page.com

From Laser:
"The forum is the place where combat (real time) flight simulator fans come to play turn based strategy combat."

Top
#2892342 - 11/01/09 12:04 PM Re: Why use Rudder in an established Turn? [Re: Dart]
Sim Online   sleepy
Hotshot

Registered: 09/18/01
Posts: 8364
Loc: Vegas
So much? I've seen worse biggrin

Top
#2892347 - 11/01/09 12:15 PM Re: Why use Rudder in an established Turn? [Re: Sim]
womenfly2 Offline
Member

Registered: 02/22/09
Posts: 769
Loc: NH
Its mostly do to non-differential ailerons which induce a yaw moment when doing an aileron turn. Some needed with a rotary vs inline engine and some from no fin ( full flying rudder), but the major feature is the ND ailerons.
_________________________
Gateway FX7026 Quad core 2.5GHz, 7.1 Audio, 8 gig ram
Windows 7 Professional 64-bit
Bose Champion-5 sound system
Samsung 2493HM LCD 24" monitor
NVIDIAŽ GeForceŽ GTS 250 w/ 1 GB GDDR3.
Direct X10
In the process of building a full size J3 Piper Cub! .. the L-4 version.

Top
#2892357 - 11/01/09 12:34 PM Re: Why use Rudder in an established Turn? [Re: womenfly2]
ft Offline
Member

Registered: 08/31/01
Posts: 967
Loc: 400' MSL
Wings travelling at different speeds with different angles of attack and different aileron deflections generating different amounts of drag. You also increase the angle of attack, giving you P factor yaw from the propeller, and the turn rate combined with gyroscopic precession on the propeller ang engine introduces a pitching moment about the world-horizontal axis which will, due to the bank, partially act in the rudder plane.

Quote normal, and noticeable in many modern day designs as well.

Top
#2892413 - 11/01/09 02:43 PM Re: Why use Rudder in an established Turn? [Re: Rama]
intramile Offline
Member

Registered: 06/27/09
Posts: 220
Originally Posted By: Rama
Originally Posted By: pakfront

So... are my assumptions about ideal flight correct?
If so, why do these crates differ so strongly from ideal?

Moreover (but isn't really represented in this sim, since you can't control Joystick stiffness), a lot of these crates were also aileron heavy... and inclination was obtained and controlled more with rudder induced roll than ailerons.


That is true.

Since you raised the aileron feel, just like to take the opportunity to point out that RoF does ailerons SUPERBLY compared to any other WW1 game. Not just realistically in terms of roll rate and various forces, but also in smoothness of the roll/aileron action.

The ailerons in RoF are not smooth, they are "jerky" - whilst in other WW1 games they are very smooth, maybe because most of those games around now were built originally for WW2 or later planes, where aileron action would have been smoother. They would not have been like this in WW1 planes.

RoF has done an excellent job here - best around by a proverbial mile. I think it is quite an achievement.

Top
#2892415 - 11/01/09 02:49 PM Re: Why use Rudder in an established Turn? [Re: intramile]
Dart Offline
Contributing Editor
Just upgraded from intern
Veteran

Registered: 09/02/01
Posts: 16447
Loc: Alabaster, AL USA
Quote:
Moreover (but isn't really represented in this sim, since you can't control Joystick stiffness), a lot of these crates were also aileron heavy... and inclination was obtained and controlled more with rudder induced roll than ailerons.


Are you trying to say that a person's legs are stronger than their arms?
_________________________
The opinions of this poster are largely based on facts and portray a possible version of the actual events.

More dumb stuff at http://www.darts-page.com

From Laser:
"The forum is the place where combat (real time) flight simulator fans come to play turn based strategy combat."

Top
#2892429 - 11/01/09 03:15 PM Re: Why use Rudder in an established Turn? [Re: Dart]
Rama Online   content
Member

Registered: 11/22/05
Posts: 583
Loc: Toulouse France
Originally Posted By: Dart

Are you trying to say that a person's legs are stronger than their arms?


I'm not trying to say anything, I'm saying that most of theses planes (at least french and brittish) were aileron heavy.
This what most of most pilots testing replica or real planes (from the memorial flight for exemple), are telling.
I posted on this forum a few month ago a translation of such a repport (for the memorial flight Spad SXIII flight test).


Edited by Rama (11/01/09 03:18 PM)

Top
#2892470 - 11/01/09 04:57 PM Re: Why use Rudder in an established Turn? [Re: Rama]
Dart Offline
Contributing Editor
Just upgraded from intern
Veteran

Registered: 09/02/01
Posts: 16447
Loc: Alabaster, AL USA
Forgot the smiley, sorry.

smile
_________________________
The opinions of this poster are largely based on facts and portray a possible version of the actual events.

More dumb stuff at http://www.darts-page.com

From Laser:
"The forum is the place where combat (real time) flight simulator fans come to play turn based strategy combat."

Top
Page 1 of 4 1 2 3 4 >
Topic Options
Rate This Topic
Hop to:


Forum Use Agreement | Privacy Statement | SimHQ Staff
Copyright 1997-2011, SimHQ Inc. All Rights Reserved.