Out of balance...... Say whhhuuut?

Unit74

Unit74

Final Approach
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Unit74
Would a paint reshoot on a Stabilator have enough paint to put it out of balance?

I just had some K2U gap seals installed on my T tail. The whole Stabilator was pulled down and once down, MX noted a pretty crappy reshoot was done.

Today he went to balance it and it was about 7" aft out. There was no way to bring it back in. I already had the max plates on the counterweight. We pulled off the wicks and that gave us .5 inches.

He ran the calcs to determine if the speed mods had enough moment to push it way out, Which it didn't. He talked to two other shops and then To Piper direct. No explanation based on what we have was logical.

Only thing he was able to note was that the paint was thick and an obvious reshoot with the stabilator still on the plane based on overspray.

Could a paint reshoot cause this much grief? As of right now, I have plans to drive the stabilator to Mena Aircraft Paint on Monday for a full strip and paint. I don't want to do this at all but what other choices do I have? Any ideas? I'm completely bleeding money on this plane right now after MX and avionics.


My MX said ask them to shoot it heavy on the leading edges and light on the trailing edges. Does that make sense?
 
Could there be any thing inside the stab.? Nests or dirt etc. Depending on the amount of paint applied, it will change the balance, but I don't think it would throw it out of spec.
Did he check it on the airplane, or off?
 
Not to be caption obvious or anything, you sure he was checked the balance properly?
 
Mud daubers can do some pretty impressive work. I found a dauber nest on the counter weight of an aileron that prevented full aileron deflection. They can accumulate over the years.
 
Checked off the plane, on a jig per Piper Maint manual. We had the manual out, verified the jig was to spec and tried to eliminate any oversight. I'm going to ask Mena to try and re-balance just in case but I'm fairly confident its off.
 
Strip it back to bare metal, remove all non factory bits and check the balance. It may be defective from the factory.
 
I'm gonna ask mx to bore scope it first to see if some dobbers got in. If nothing is found, we ar stripping and repainting.
 
IMO paint can easily do this, check the balance once it is stripped, before reprinting it.

Brian
 
Ok...so Monday I dropped it of in Mena. Their MX had basically the same result balancing.

Using a calibrated pocket knife, one of the guys scraped off paint in various places. He found "filler primer" in a few spots . I don't know what that is, but it's leading to a cause of excessive weight.

They are stripping a Mooney today and will fit me into that job. They will rebalance stripped and call at that point.

Fingers are crossed. They do a lot of balancing and said they have never seen this before.
 
Unit74 said:
Using a calibrated pocket knife, one of the guys scraped off paint in various places. He found "filler primer" in a few spots . I don't know what that is, but it's leading to a cause of excessive weight.
Click to expand...

Bondo. Haha.
 
denverpilot said:
It was a joke Tom. Haha. Just helping along his worst fears... :)

Airplane ownership, ain't it grand? ;)
Click to expand...

Ive got him on ignore so I didn't see it.


Paint shop called today. They said there was lacquer paint under enamel paint. Once they got it all off, the stabilator balanced nicely. He commented that someone laid it on thick too. That's why we were so far out. Nothing in the books. ****es me off.

Should be out of paint early next week and back on the plane Thursday.
 
We are completely stumped on this. I have talked to 3 APs, Bartelt Aviation who is the best PA32 dealer anywhere and all at baffled.

Without paint, we are at -20". With paint, we end up at 43". Limits are -12 to 37". Painter was well aware of the balance concern.

We are totally left with a head scratcher. Trying get to a knowledgable person at Vero Beach is incredibly difficult. Not sure what to do at this point. After a full strip and paint, we ended up right back where we were to begin with.

Any ideas?
 
No. No evidence of a reskin. It was resprayed over the factory lacquer. Other that that, nada. Parts look original inside and out. We scoped the whole thing.
 
Whenever something goes that far out of whack in my biz, I always check the test gear itself. Just a thought.
 
We went back into the manual, verified the tool was correct did everything by th book, mm by mm and back at my MX, we are literally back where we started.

I have come to the conclusion there is no other answer other than the plane was flow like this for the last 2300 tach hours.....that's what it shows from new. Nothing is askew, 3 APs at three different shops all had the same results. Something is wrong and I don't think it's induced. Either the book is wrong or the plane left piper well out of spec.

Still trying to get Piper involved. We will see hat happens.
 
Does the aircraft have speed mods? I was reading yesterday, can't find it today, about some speed mods, and some other models require heavier components in the stabilator with the mod. The PA32 doesn't require it. Wondering if yours has the speed mod and also the heavier component in the stabilator, which it shouldn't
 
Yes, the whole reason we pulled it off was installation of a K2U gap seal. No WB plates were included in the kit. We ran the numbers to determine if the kit was the prob and it only moved the moment 1/2" forward.
 
Hey, it could always be worse. The following was after asking to repaint my ailerons on the -35:

Me: I think the ailerons might be magnesium - likely just the flaps though.
A&P: (After stripping the paint) Nope - bond-O
Me: serious?!
A&P: I'll send pics or you can come down and take a look
Me: (edited for the bashful)

Yes, we got up close an personal with the ruddervaders as well - no bond-O, but did scare me ..


So when you packing that station wagon and going on vacation?
 
We are working out how to get it to the min book standards for balance.

Once I can to that point I'll be back in the air. Waiting on a call back from Piper in Vero Beach right now.
 
brian] said:
Hey, it could always be worse.
Click to expand...
No kidding. Brother-in-law just told me about a Lear 25 that just came in. It's been parked for 5 years and ferried to his RS. Guy bought it without a pre buy. $100K supposedly. Good deal except it's has 30 serious discrepancies before even being opened up, both flaps need overhauled due to cracks. Serious logbook issues. One engine has timed out rotor discs and the other is fodded out. Junk basically.
 
Can you measure the skin thickness? And then compare to what it should be? Maybe the factory used the wrong sheet of Al.

Can you just strip the whole thing to bare?
 
Getonit said:
Can you measure the skin thickness? And then compare to what it should be? Maybe the factory used the wrong sheet of Al.

Can you just strip the whole thing to bare?
Click to expand...


Well, we just had it stripped. However, I'm not going to strip off new paint at this point.
 
Unit74 said:
We are completely stumped on this. I have talked to 3 APs, Bartelt Aviation who is the best PA32 dealer anywhere and all at baffled.

Without paint, we are at -20". With paint, we end up at 43". Limits are -12 to 37". Painter was well aware of the balance concern.

We are totally left with a head scratcher. Trying get to a knowledgable person at Vero Beach is incredibly difficult. Not sure what to do at this point. After a full strip and paint, we ended up right back where we were to begin with.

Any ideas?
Click to expand...
Let me get this straight. Stripped bare you're at -20 and after paint you're at 43? That's a 63" difference with just a couple of coats of paint.
I take it that the negative number is forward of datum. Has there been any change in the balance weight between times? I assume that the balance weight is the type with changeable plates.
 
No, 23" aft of datum. Missing the dash before 43
 
OK. So a difference of 20" between paint and no paint. That seems like quite a lot anyway. IIRC my stabilator on my 140 only changed a few inches between bare and paint. And fell right in the middle of the spec range, with paint. I would suspect that it (your stab.) never was in spec. since new. You can add more paint forward of datum, but I can't garuntee the paintjob to hold up due to the amount of material needed.
 
I did have extra coats put on the leading edge and min on the trailers get edge. It seems so far everyone I have talked to who has had a physical hand on the plane agrees this Stab left Piper unbalanced.

Plane has flown 2400 tach hours in such condition.
 
SRM?


Nothing to trim off the back.
 
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