tkatc

tkatc

Well Known Member
I have flown in 2 6As and 1 9A. The first 6A didn't really tell me much because I didn't fly it that much....the 2nd 6A was flown during my transition training and I remember using an enormous amount of right rudder. I recently flew a 9A and was surprised at how little pressure I needed.

It occured to me that it might be that the 7A and 9A have a larger rudder surface and less rudder pressure was needed...is this the case or am I just crazy?
 
rigging and engine torque

the only rudder that is really needed is on acceleration through take off and climb out, for ground handling, and while landing... in cruise, and for most routine maneuvers, you should not need any rudder input.

i suspect that there was a notable difference in engine / prop between the planes... perhaps one of the 6s had a larger engine with a constant speed prop...
 
I have flown three different -6As and they all seem to require much more rudder input than my large ruddered -7A, even though they were all 360's with C/S props, just like mine.
 
[email protected] said:
... perhaps one of the 6s had a larger engine with a constant speed prop...
Click to expand...

Yes, the 7 & 9's have a larger VS and rudder than the 6's. I seem to remember that there were two different rudders for the 6 and even those were smaller than the 7 & 9's, which share the same VS and rudder.
 
I understand the 4 and 6 typically use more
rudder on takeoff and climb.
I am guessing the older design vertical fins
don't have any or less offset than the later models.
The rudder size is also a factor.
The engine mount offsets may have changed, also.
Tom
 
Our 6A didn't have a fin offset...

....but a multi-RV builder had the attach piece from a -7 fin, with the 1/4" joggle in it. He gave it to us and mentioned that without it, we'd definitely have to have a rudder trim tab.

The-10' don't have any fin offset and just about all of them either have an electric trim tab fabricated, or a wedge added, like mine.

Could be different issues,

Best,
 
I have quite a bit of 9A time in two different 9s. Definately, my short "classic" tail 6A takes a lot more rudder on the takeoff roll & initial climb. Past that point, my rudder tab kicks in, since the vertical stab has no offset. The engine is offset, probably about the same as other models.
All that rudder makes it feel a bit closer to a WII fighter.......which makes it a bit of fun, in a way. :)

L.Adamson --- RV6A
 
Are the Ailerons Also Playing a Part?

I'm assuming (bad word) that the "6" also incorporates the combination of differential/Frise ailerons that are found on the "9". However, if the ailerons are shorter on the "6", might this also explain some of the difference in adverse yaw?
Not sure.
Terry, CFI
RV-9A N323TP
 
terrykohler said:
I'm assuming (bad word) that the "6" also incorporates the combination of differential/Frise ailerons that are found on the "9". However, if the ailerons are shorter on the "6", might this also explain some of the difference in adverse yaw?
Not sure.
Click to expand...

I don't think so. I only use aileron to counteract any roll from torque (and a crosswind). It's more noticeable with a touch & go scenario. My 6A & constant speed prop.........gets a bit torqued up with the last third of throttle.

L.Adamson -- RV6A
 
pierre smith said:
....but a multi-RV builder had the attach piece from a -7 fin, with the 1/4" joggle in it. He gave it to us and mentioned that without it, we'd definitely have to have a rudder trim tab.

The-10' don't have any fin offset and just about all of them either have an electric trim tab fabricated, or a wedge added, like mine.

Could be different issues,

Best,
Click to expand...

Pierre's right about the trim tab. Could make a huge difference. I flew around for a few months with no trim tab and I needed a lot of right rudder. Obviously it was more pronounced in takeoff and climbout. Once the trim tab was added, I don't need any at all at cruise speeds. Takeoff and climb out still need a little, but not much.
 
Wheelpants and Fairings can cause grief if not exactly aligned. I first flew my 7 around with them off and required hardly any rudder at all. When they were first installed I did not like the way the airplane felt as I needed a lot more right rudder climbing out and also had to add left rudder when approaching to land. It took a little tweeking to get the aircraft to fly the way it did without the fairings and pants.
 
Rudder, Rudder, Rudder

L.Adamson said:
I don't think so. I only use aileron to counteract any roll from torque (and a crosswind). It's more noticeable with a touch & go scenario. My 6A & constant speed prop.........gets a bit torqued up with the last third of throttle.

L.Adamson -- RV6A
Click to expand...

If you use enough rudder with the power addition, it won't get "torqued up". And it isn't "torque" that causes the rolling tendency, it's "P" factor. All solved with rudder, NOT aileron. If you oppose the rolling tendency with aileron, you will be flying with the ball not centered. NOT GOOD.

-all from: "Aerodynamics for Naval Aviators" (Highly recommended reading.) The aerodynamics apply to ALL aviators, however.

I have flown T-6, P-40, AD-1 Skyraider, and F-4U Corsair. They all have big motors and Rudder Trim, and need it. Rarely need aileron trim, if the rudder is trimmed first.

What I am saying is: If you feel a rolling tendency to the left after takeoff, DON'T use aileron to stop the roll. Leave the stick in the middle, and use right RUDDER to stop the roll. If you do that, you will find that the ball will be in the middle, where it belongs.

Whew! I feel better now.............:eek:. Sorry for the rant.
 
PCHunt said:
What I am saying is: If you feel a rolling tendency to the left after takeoff, DON'T use aileron to stop the roll. Leave the stick in the middle, and use right RUDDER to stop the roll. If you do that, you will find that the ball will be in the middle, where it belongs.
Click to expand...

I use all the rudder it takes to stay on the centerline & extrended centerline through the climb. So if that's what it is, then that's what it is. My hand may not even really be doing anything with the aileron, considering forces are so light, while the rudder forces are strong.
I hope you feel a bit better....

L.Adamson ---- RV6A
 
You must log in or register to reply here.