Piper is not flying true

greddawn

greddawn

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gred
I had a quick question for the PA28 experts out here. (PA28-180) I got the plane out of annual a few weeks back and noticed something was off. The plane seems to want to make right turns out of straight and level coordinated flight.

Here is what I did to troubleshoot:

1. Weight - disqualified - by flying with CFI who is within ~5lbs of me, full tanks, and burning the right tank down to tabs. Removed baggage.

2. Weather - disqualified - flew several headings in different wind conditions and at different times. Problem was consistent.

3. Nose trim - don't think so - Here is what I did:

Set nose trim to neutral->> Plane REALLY wants to yaw to the left (think almost full deflection on the ball). Plane will fly relatively level.

Two turns nose trim to the right ->> Plane requires minor right rudder input for coordinated flight. Requires 15-20 degrees of YOKE deflection to the left. (think cross control) Anything else beyond that made it worse.

4. Poor rudder use - Guilty. Not causing this problem though.

What say you?
 
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What exactly did they do during the annual? Anything that could have affected the rigging of the control surfaces? If I got my plane back from my (excellent) shop and there was a big change like that, I'd be walking straight into the office and asking the IA/A&P what could possibly be up. When I get my plane back from annual, I expect it to be in as god or better condition than when I dropped it off (it is an annual inspection so sometimes things get repaired/upgraded, after all!).

Flap/aileron rigging info from the master (may he rest in peace):

http://www.pipermods.com/rigtool.htm
 
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Yea we are going to need the whole story first. What if anything did they do during annual that could have effected it. Control rigging, cables, turn coordinator? Did you say anything to the shop?
 
Called the mechanic this morning and he said that he is going to wheel it back over and take a look. I asked him if he made any changes to cable tensions, etc. and he said that he would need to pull his logs to remember what they did for the annual and he would call me back afterward. His suspicion was that it could be corrected with the nose trim, but I don't know how he is going to correct left yaw right roll with one trim setting. I'll report back when he's done.
 
Doesn't the PA-28 have a rudder-aileron interconnect? Perhaps this was misrigged (or disconnected)?
 
The plane seems to want to make right turns out of straight and level coordinated flight.
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One thing that will make a PA-28 fly crooked is if the nose wheel faring and the rudder are not synchronized. In fact one PA-28, the Warrior IIRC, is not airworthy without a nose wheel faring because it is the airflow force on the faring that centers the rudder. Others, again IIRC, have centering springs.

If you check in flight and see the turn with ailerons level, this might be your problem. Of course if you can't get both ailerons level with the flaps at the same time, then that's another rigging problem.
 
airdale said:
One thing that will make a PA-28 fly crooked is if the nose wheel faring and the rudder are not synchronized. In fact one PA-28, the Warrior IIRC, is not airworthy without a nose wheel faring because it is the airflow force on the faring that centers the rudder. Others, again IIRC, have centering springs.

If you check in flight and see the turn with ailerons level, this might be your problem. Of course if you can't get both ailerons level with the flaps at the same time, then that's another rigging problem.
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Explain the 28R then
 
And you said the fairing or springs are a required part of the system, the 28R has neither, and the exact same rudder system
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Hey, I don't design them. I just fly them. I also haven't studied the TCDS. But I do know from personal experience that poor nose wheel/rudder rig can produce a symptom like the OP's.

But, to your point, the system in the Arrow is different because the nose wheel is not connected to the rudder when the gear is retracted. Hence less friction. Maybe that is enough to account for the design change.

Since you're interested, maybe you could study the TCDS and the drawings to figure it out instead of just carping. Let us know what you find.
 
airdale said:
Hey, I don't design them. I just fly them. I also haven't studied the TCDS. But I do know from personal experience that poor nose wheel/rudder rig can produce a symptom like the OP's.

But, to your point, the system in the Arrow is different because the nose wheel is not connected to the rudder when the gear is retracted. Hence less friction. Maybe that is enough to account for the design change.

Since you're interested, maybe you could study the TCDS and the drawings to figure it out instead of just carping. Let us know what you find.
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Carping?

Sory I chimed in when you posted false information about the PA28 rudder system. It won't happen again
 
BTW I did look it up, and the wheel fairing isn't what you can't take off
 
Make sure the steering rods , stop bolts and horn haven been bent during towing...if they aren't straight it will totally screw up the rudder and rudder trim rigging. Your rudder trim shouldn't be close to the stop at all in cruise.
 
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Had/having the same problem with our club's PA28-181. So far mechanics have drastically improved it from what it was (would have you in a 30 degree bank or more within 30 seconds) to just being a small nuisance. It turned out to be a combination of one flap being slightly lower than the other and poor rigging. Mechanics said things like this usually start out with someone adjusting something that didn't need to be adjusted.
 
They have the plane frankensteined right now checking all the cables and seatings. Mechanic said nothing was adjusted in annual except the nose trim was brought to center. I'll report back!
 
greddawn said:
...Mechanic said nothing was adjusted in annual except the nose trim was brought to center...
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Is it just me or does that look, sound, smell and feel like a smoking gun?:rolleyes:

DanielH said:
Mechanics said things like this usually start out with someone adjusting something that didn't need to be adjusted.
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In fact at nearly 300 hours in pa 28's 140 161 180 200's. I am not sure i have ever hit the stop on the rudder trim.

Sent from my DROID BIONIC using Tapatalk 2
 
TriGear28 said:
In fact at nearly 300 hours in pa 28's 140 161 180 200's. I am not sure i have ever hit the stop on the rudder trim.

Sent from my DROID BIONIC using Tapatalk 2
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I have a great story for you involving a 350 lb instructor and his nose trim settings.
 
greddawn said:
They have the plane frankensteined right now checking all the cables and seatings. Mechanic said nothing was adjusted in annual except the nose trim was brought to center. I'll report back!
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Yeah. It's rudder trim. On one of my first post-annual flights I flew one pattern and the cocked rudder scared the whee out of me.

Try flying with the door popped open. Same thing.

You don't like having the plane to go somewhere on its own.
 
Update: Spoke to the mechanic. There was carpet on the right seat floorboard snagging a rudder pedal, effectively rendering my nose trim useless. It doesn't explain the right roll. He checked all the cables and turnbuckles and confirmed they were installed correctly. He said that he can adjust the ailerons if necessary, but to fly it first and see how it handled once I got it trimmed out. Rainstorms moved in unfortunately. I will try and fly it tomorrow and report back. Thanks again for all the suggestions.
 
Sounds like the right steps. Right rudder = Right roll in that airplane even with no yoke/aileron /roll input. One step at a time.
 
Mystery solved. Got it trimmed and flying true today. The passenger side carpet (along the side-wall, not the floor) was snagging the right rudder pedal, causing a right rudder input even when I set it to neutral. Mechanic had tightened up the panel and secured it so it wouldn't be a problem in the future. Thanks for the suggestions and comments guys - a good lesson learned.
 
I have a PA-28 mx manual scanned to PDF if you're interested. It consists of 4 huge volumes.
 
greddawn said:
It doesn't explain the right roll. He checked all the cables and turnbuckles and confirmed they were installed correctly. He said that he can adjust the ailerons if necessary...
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Adjusting ailerons to lift a heavy wing is a total waste of time. Rigging one aileron down just makes it push upward through the system and push the other aileron down. Adjusting wing incidence or an aileron trim tab are the only ways to fix a heavy wing.

Dan
 
Dan Thomas said:
Adjusting ailerons to lift a heavy wing is a total waste of time. Rigging one aileron down just makes it push upward through the system and push the other aileron down. Adjusting wing incidence or an aileron trim tab are the only ways to fix a heavy wing.

Dan
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Agreed... All it will do is cant the yoke one way... Kinda like a steering wheel on a car that when going straight the wheel shows it is turning..:(
 
A captured right rudder pedal will initiate a roll in any aircraft.

Several lessons here:

1. A good post annual pre-flight - controls free and clear? That includes the rudder.

2. Pilots need to understand how airplanes fly and what various control inputs do.

3. a door open in a Cherokee is nothing to be that concerned out. Fly the plane - you will not fall out.
 
Dan Thomas said:
Adjusting ailerons to lift a heavy wing is a total waste of time. Rigging one aileron down just makes it push upward through the system and push the other aileron down. Adjusting wing incidence or an aileron trim tab are the only ways to fix a heavy wing.

Dan
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Agree that tweaking the ailerons is complete waste of time. Had a company PA-32R-300 back in the 1990's and encountered this problem. The know-it-all boss wanted to tell us how to fix it - "tweak the ailerons" he said. After several attempts and subsequent test flights during which the only thing that changed was the angle of the yokes in straight and level flight, I finally asked him if he'd let us follow the manual procedures for a change.

However, most if not all PA-28 and PA-32 series Pipers as I recall do not have an aileron trim tab and the wing incidence is fixed. (It does not have an eccentric cam bushing on the rear spar as does a high-wing, strut-braced Cessna.) According to the SM, the only way to correct a wing-heavy condition on one of those Pipers is to tweak the flaps - typically running the flap on the heavy wing down just a tiny bit, but if the travel is available, running the opposite flap up a bit works too and creates less adverse yaw.
 
150Mike said:
Agree that tweaking the ailerons is complete waste of time. Had a company PA-32R-300 back in the 1990's and encountered this problem. The know-it-all boss wanted to tell us how to fix it - "tweak the ailerons" he said. After several attempts and subsequent test flights during which the only thing that changed was the angle of the yokes in straight and level flight, I finally asked him if he'd let us follow the manual procedures for a change.

However, most if not all PA-28 and PA-32 series Pipers as I recall do not have an aileron trim tab and the wing incidence is fixed. (It does not have an eccentric cam bushing on the rear spar as does a high-wing, strut-braced Cessna.) According to the SM, the only way to correct a wing-heavy condition on one of those Pipers is to tweak the flaps - typically running the flap on the heavy wing down just a tiny bit, but if the travel is available, running the opposite flap up a bit works too and creates less adverse yaw.
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And that's why Cessnas are better than Pipers :D:lol:
 
Dan Thomas said:
...Adjusting wing incidence or an aileron trim tab are the only ways to fix a heavy wing.
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The Piper manual tells you to adjust one of the flaps, there is no way to adjust the wing incidence as you do on a Cessna.
 
I absolutely agree with the thorough pre-flight, however the rudders felt normal on the ground throughout taxi and even during rotation. Couldn't recognize any sticking of the rudder until we were airborne and turning out of the pattern. Once again, not unsafe, just uncomfortable and required correction.

Not sure where the door comment came from, never had any issues with that. I would fly doors off if I could, it's so damn hot down here!
 
comanchepilot said:
Several lessons here:

1. A good post annual pre-flight - controls free and clear? That includes the rudder.
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That sounds good and all, but remember the PA-28 nose wheel is directly connected to the rudder pedals, not through bungees like Skyhawks.

How does one check "free and correct" on the ground? Especially for a yielding obstruction like carpet, when you are pushing through so much resistance in the system?
 
comanchepilot said:
...3. a door open in a Cherokee is nothing to be that concerned out. Fly the plane - you will not fall out.
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Yeah, you won't fall out. Looking down at the earth from 11,000 feet from the passenger seat is concerning.

I did fly the plane when it was me. I'm here writing about it.

It concerned me the last time the door was unlatched open because we were practicing flying in tandem for the Piper flight to Oshkosh, and the plane kept wanting to fly into the guy on my left.

The first time was when I was a student doing solo pattern work.

Take the runway. Apply full power.
"Did I check the door latch?"
Reach up. Thump. (I unlatched it.)
"Awwww sh!!!!!"
Heart rate goes to about 190bpm.
"CFI's voice: FLY THE PLANE!"
I flew the pattern and landed normally.
 
Jaybird180 said:
And that's why Cessnas are better than Pipers :D:lol:
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Mom used to tell me that "comparisons are odious."

I generally prefer Cessnas too, but wouldn't go so far as to suggest what you did. Why do you need to offend all Piper owners in one fell swoop?

Consider this - at least the Piper wings (low wings that is) are held on by a lot more than just 3 bolts each! (The Cessnas have only 2 in the root and 1 at the end of the strut.)
 
150Mike said:
Why do you need to offend all Piper owners in one fell swoop?
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Well, looky here...GA n00b doesn't get the joke...careful, that reputation may follow you on PoA (and elsewhere).
 
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