I need dimensional information for my PA-28-181 Archer II ailerons to determine if a previous reskin repair changed the washout shape. There is an aileron bias condition in flight which was not corrected by a complete rigging inspection/adjustment. Thx
Archer II Aileron Technical Drawing
-
ParticipantParticipant
Hi Brendan;
I apologize for not getting back to you right away.
Can you tell me more about why you think the aileron repair was done wrong?
For instance,
Can you sight down the trailing edge of the aileron and see a twist?Are you seeing a mis match between where the inner end of the aileron matches the outer end of the flap?
Or where the outer end of the aileron marries up to the wing tip?
Do you see an obvious problem with the repaired aileron when you compare it to the other aileron?
Can you send a picture of what looks wrong?
Thanks
SteveParticipantSteve,
My inquiry is related to my aircraft having a left roll tendency (right yoke pressure is continually required). It’s had this issue since I purchased the aircraft 6 years ago now. My A&P and I have worked on this issue many times without resolving the problem; we made improvements but apparently have not found the root cause. We’ve followed the Piper Service Manual rigging procedures to get the surfaces aligned and cable tensions within spec. So, I’ve been looking for possible airframe and/or control surfaces that have been repaired or are out of spec since the plane left the factory 46 years ago. Per my calibrated eyeball, the aircraft looks straight, nothing visually jumps out. I’ve spent some measuring various points on the wings and control surfaces using a laser transit in attempt to find anything that measures suspect, so far, the measurements are amazingly symmetrical; with little to no design information, I’m assuming symmetry is good. The parts and service manuals are very good procedurally, but they don’t provide much if any explanation of what the results of an adjustment will be or what to troubleshoot if adjustments don’t solve the problem. Unfortunately, some technical information is tribal and/or unobtainable from Piper. Since my original post, I’m systematically going through the rigging procedures again. The rudder system on PA-28-181 incorporates a series of springs; rudder pedal to nose gear bungees, nose gear to firewall centering springs, and inflight adjustable rudder trim. All of the springs influence each other during control inputs, the bungees and obviously the rudder trim are adjustable, but the nose gear centering springs are not adjustable, so I’m looking carefully at the nose gear wheel/fairing to ensure they really are in alignment with the aircraft center when rudder pedals and rudder are centered too. Thoughts?
ParticipantHi Brendan;
Again, sorry for the delay in responding.
It sounds like you’ve done a lot of good troubleshooting.
There aren’t too many tweaks to combat your left wing low tendency. The easiest is to slightly droop the left flap. Add a bit of length to the left flap actuating push rod.
This procedure is detailed in the PA28-181 Service manual Chapter 27-50-00 Page Locator 2 D 7 para (5) d:
“To remedy a wing heavy condition during flight, adjust flap
down from neutral on heavy wing, by lengthening control rod.
Check each rod inspection hole to make sure there are suff icient
threads remaining and that a wire cannot be inserted through
these holes. Maintain a minimum of 0.375 inch thread
e n g a g ement on rod ends without check holes. Do not raise the
flap of the other wing above neutral”EZ Does it, Make slight adjustments to lengthen the flap actuating rod until she flies straight and level.
Please let me know how this tweak works out.
Steve
ParticipantI’ve been down the ‘lowering flap for heavy wing’ road before a few times; the result has been negligible difference if any. What I see out the window when I let the yoke free is the LH aileron comes up and the RH aileron goes down and the plane rolls left; of course the yoke turns left as expected. Unchecked, the airplane would be in a steep turn in less than 5 seconds, so you can imagine this is a little annoying especially when trying to fly a heading in IMC conditions. If I hold the right pressure on the yoke to make the ailerons trail reasonably neutral the plane will fly level and I can center the ball with the rudder trim. Something is causing an aerodynamic imbalance which manifests with the aileron movement. This past weekend I spent half a day checking the nose wheel and rudder alignment. The nose wheel/fairing is turned a few degrees right of center. My Archer has the nose gear centering springs that Piper started adding ~later 70’s and is the subject SB 1167 from 2006. These are really heavy extension springs that connect each side of the nose gear steering arm to the firewall. There is no adjustment on the centering springs so it’s a compromise of steering bungee adjustment, cable tension, and rudder trim to make the nose wheel and rudder centered when plane is jacked and leveled. It appears that my plane came from the factory with the centering springs, because there is no record of kit 767-519 being installed. The springs visually appear to be correct but can’t find any specifications to confirm. The spring P/N is 67168-00 which may have been superseded by P/N 487-483. Unfortunately, neither the rudder or nose gear can be observed in flight from the cockpit; I may need to resort to mounting some external cameras to see what’s happening in flight.
ParticipantHi Brendan;
Next suggestion:
Remove the two steering centering springs and swap them–to determine if the springs are the problem. If, after swapping you have a right turning problem, the obvious conclusion is the springs are not matched in “power” or length.Steve
- You must be logged in to reply to this topic.
