Right Rolling tendancies

I am a student pilot, and owner of a 1974 PA28-151. After my last annual ( I believe the rigging was redone) my plane started to roll severely to the right when in flight. Mechanics have since adjusted the flaps several times, somewhat alleviating the problem,and now it still rolls, albeit slower and not as severely. The flaps and ailerons now do not line up. I wonder if anyone else out there has had this problem and appreciate any input!

Comments

  • Rigging is time consuming and proper tools and knowledge are required. My stabilator, ailerons, rudder and NW steering rigging cost me four hours and that included cable tension adjustment where necessary. It flys straight as ever since then. Those four hours were not included in the 17 hour Annual inspection charge. It may have even been five hours (it was three years ago).

    If yours flew straight beforehand and lousy after the Annual it was probably screwed up.
  • It was probably screwed up during the annual. The first thing to do is rig it
    back to neutral specs, check to see if any residual roll remains, amd then adjust the flaps tp eliminate the residual
  • Maybe a silly question, but is your rudder trim neutral?
  • Well, thanks everyone for your quick responses...what a great find this place is...!

    Ok, to answer a few questions. Yes the rudder trim was neutral, until my last flight training session, when the instructor fiddled with it somewhat to adjust for the roll. As far as why it was rerigged, I have no idea, but will ask next time I speak with the mechanic who did so. The log book was endorsed by an appropriately rated pilot (who happened to be renting the aircraft from me for business purposes from time to time so would have no reason "help" the mechanic)...he found it to be fine. When I was transporting it from Canada to Washington, as I did not have a pilot's license I had to hire a Canadian pilot to bring it down with me, and then have a US pilot meet us to carry on to where I am now based. (gotta love bureaucrasy)...Both immediately noted the right roll, as have two instructors, and of course myself.
    So, now I am in the midst of two different mechanics trying to sort it out. As there are no more flap adjustments available, the mechanic who rerigged wants everything put back to neutral, which at this time it is not, and to begin at square one. This will probably happen next week, and hopefully I will not have to foot the bill! (Could be a whole shop day!)

    Will keep you all posted. I appreciate all your help and any other ideas you may have! Hopefully this will be rectified. I don't need anything else to think about while I am training!!!

    Smooth Skies
    Flygirl
  • I can't imagine anyone adjusting the flaps first -- that comes last.
  • Ok, found out that rerigging was done due to worn cables. Also had a comment that possibly someone had nudged the wing while it was parked. Now for the latest, still under investigation, it seems that the wings do not match! Mechanic says there is an 11 degree difference in dehedral, and one wing has a bolt hole that is standard while the other does not! So, it would seem that the whole thing was rigged before my annual to compensate for this, eliminating the roll. When it was rerigged it was done "properly", without compensation resulting in right roll. I have dropped off every logbook/mechanical log I have to the mechanic who discovered this, and am waiting to hear what he thinks may have happened and how it can be fixed...who woulda thought!......I had come across a few letters written between a law firm and the people who owned it years ago, and there was some sort of issue with dirty fuel...hmmmm...
    That's it so far...will post results to this mystery.
  • Flygirl Wrote:
    > Ok, found out that rerigging was done due to worn
    > cables. Also had a comment that possibly someone
    > had nudged the wing while it was parked. Now for
    > the latest, still under investigation, it seems
    > that the wings do not match! Mechanic says there
    > is an 11 degree difference in dehedral, and one
    > wing has a bolt hole that is standard while the
    > other does not! So, it would seem that the whole
    > thing was rigged before my annual to compensate
    > for this, eliminating the roll. When it was
    > rerigged it was done "properly", without
    > compensation resulting in right roll.

    This almost seems like a joke but today who knows. What mechanic will re-rig an aircraft because of "worn" cables? Does he mean they were tensioned to proper specs? Were they worn (frayed) and replaced? On top of that, what is this about two different wings? How much “ re- rigging” will compensate for this and who in their right mind would sign this monstrosity off?
  • Lynn, nothing about your post makes sense. Like GM says, you don't rerig due to worn cables, you replace. If the two wings are indeed 11 degrees different in dihedral, then the plane looks like a crippled bird on the ground -- 11 degrees is a LOT; quite visible to the eye. I sort of look askance at that number.
  • PA 28 dihedral is 7 degrees. If one wing is different by 11 degrees, then that wing is either drooping downwards 4 degrees or pointed up at 18 degrees. Either would make the plane look exceedingly lopsided -- I just don't believe that one wing is 11 degrees different from the correct number; that much would have caused Lynn to reject the plane during the prebuy. It does sound though, like the spar fittings on one side are damaged and need to be replaced. With that sort of damage, I'd also be quite concerned about an improper progression of the washout along the semispan of that wing.
  • Hi Everyone,
    Well, I have passed on and asked questions of my USA mechanic using all of your responses (tough being a newbie, as this is all a new language for me!)..thanks to everyone.

    He is now pouring over old log books. I did inquire re the following. He spoke with the Mechanic in Canada and has told me the following:

    Both forward aileron cables were replaced. The plane was rigged to spec, but not with knowledge of the wings differential of, yes, 11 degrees on top of the 7. (oddly, it is NOT noticeable).. As it was rigged to spec, and no correction made for the difference in dihedral the result is the right roll tendancy. This plane did not roll at all previously. I have owned it since March 2008...(I knew nothing about planes previously, or flying, and it just kind of came my way.) It had had a full annual upon purchase, and as it was a US plane being brought to Canada underwent full inspection.

    AS for the the spar fittings, I have mentioned it . Now I am waiting for his next verdict, after reading all past mechanical notes.

    Thanks to everyone who has helped me along the way with this. I will post results and appreciate any more insight you all may have.
  • Hi Flygrl.
    I as well am concerned, but I am by no means an expert or mechanic.
    Tom has a good point about having him or another certified POS member take a look.....if you are willing.

    If one of the certified POS members takes look as a third party perspective, they may find the root cause. Again, I am NOT disregarding your current mechanic at all.
    I think we are just looking out for your well being and safety.
    Im not sure how easy it would be to have someone look at your plane at your current location.


    -Vic
  • I agree with Tom. However, an 11 degree difference in dihedral angle is glaringly obvious, even to the naked eyeball. It can't be missed. You are saying that the deflection angle between your two wings is 25 degrees when it should be 14 and that the fuselage is crooked with respect to the wings. If it can't be seen, something else is going on there to mask it. I'm also wondering about the progression of washout along the semispan -- has that been checked yet? Also, it sounds like there is a possibility the carrythrough spar may be bent -- has that been checked yet? And the nonstandard bolt and holes sizes are exceedingly serious re the possibility of eventual return to flight.

    Since there is no way to adjust dihedral on a PA28, IF the 11 degree excess on one wing is true, then something is BENT; check the carrythrough spar for buckling. IF the 11 degrees is true (and I have some doubts about that) then this plane may require the replacement of the carrythrough structure, spar attachment fittings, and at least one wing. I wonder if the discrepency might be 1.1 degrees rather than 11 ?
  • It doesn't pass my smell test either. I'm not saying that the mechanic is wrong, but somehow, something doesn't appear to be getting communicated. An 11 degree difference from stock in dihedral on one wing would mean that one wingtip would sit almost 3 feet higher than the other -- I just can't believe that wouldn't be visible to the eye.
  • She's not jerking our chain, but there is a communications gap -- I do not believe that one of her wingtips is 'off' by three feet.
  • This is just a test:

    jerking our chain

    End of test.

    Egads! Leigh, I thought you were joking, but it's true!
  • Hey everyone...I am NOT pulling anything...just conveying what I am being told. And that is truth. The only correction I have to some of in regards to the bolts. Apparently, one wing has some sort of bolt hole that is supposed to be there, and the other one doesn't .

    I will keep you posted when I hear any news..(why would I make this stuff up!?)...I have not flown since reading all these posts! Nervous now.

    Going to call up the mechanic right now and check for updates., ( and bolt hole clarification) and go see him next week (hopefully with a savvy mechanical guy!)

    Let ya know what happens. Stay tuned.

    Flygirl for real
  • Me again..I will also try to post photos for you all to see that it really is not noticable...
  • Lynn, if it is not noticable, then it is NOT out by 11 degrees. I don't know how to say it any plainer than that. The tangent of 11 degrees is about 0.1944, which would be about 2.75 feet displacement at the wingtip -- that is just impossible to not notice. Please confirm or disprove the 11 degrees with your mechanic; it makes no sense as stated.
  • Give the poor girl a break. All she has done mixed up the term dihedral with differential.

    Her wing dihedral isn't off, her aileron differential is.


    But it sure has been fun reading all you geniuses debate the impossible.

    PilotKris
  • Aileron differential settings have no impact whatever on roll tendencies -- all they do is affect the neutral yoke position, the pitching moment, and the tail download.
  • You're right Jim, now way her ailerons are out of rig (aileron differential out of spec being symptomatic).

    Her whole plane MUST bent.
  • PilotKris Wrote:
    > But it sure has been fun reading all you geniuses
    > debate the impossible.
    >
    > PilotKris


    PilotKris Wrote:
    > You're right Jim, now way her ailerons are out of
    > rig (aileron differential out of spec being
    > symptomatic).
    >
    > Her whole plane MUST bent.



    Welcome to the debate.
  • I never said her plane was bent; I said I didn't believe an 11 degree difference in dihedral because it would have been visible. Everyone participating in the thread knows that what I said can't be construed otherwise :-)
  • JimC Wrote:
    > "I never said her plane was bent"


    JimC Wrote:
    > "Since there is no way to adjust dihedral on a
    > PA28, IF the 11 degree excess on one wing is true,
    > then something is BENT; check the carrythrough
    > spar for buckling."
  • So FlyGirl, what's the verdict?

    Is your plane really bent or was the rigging just out of whack?

    PilotKris
  • Yeah....What is the verdict?
    I hope you are not knee deep in arguements with your mechanic or...worse knee deep in bills now from this discovery.

    We hope is was only rigging and easily fixed with a GOOD rigging.

    :-)

    Let us know what's cookn on your side!

    -Vic
  • Flygirl is no longer active on this forum. Her initial report of an 11 degree difference from stock in dihedral between the two wings was not correct. I note in passing that when my if/then conditional was "quoted" above, the quoter boldfaced the 'then' part of my statement while leaving the 'if' part of the conditional unhighlighted, thereby misquoting me.
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