Here's a thought about paint jobs

[cliffy]

If you have had your plane repainted of course everyone has the flight controls re-balanced as required (right?) BUT, did you find anywhere in your logs that the elevators were re-rigged per the Mx manual or were they just re-installed? How did the shop adjust the spring bungee position without  levels and a trim board?

[scottfromiowa]

I used to watch Cheers a lot years ago.  There was a know-it-all character on the show named Cliff.  He didn't ask questions, but rather gave information that was not generally helpful it was trivia for trivias sake.  I found him annoying.

 

On the other hand someone that would give me information that discussed what the specific results were for something to be dangerous or catastrophic and why.  That is someone I can learn from.  Maybe someone that could site examples of something resulting in an accident/incident.

 

I would perefer that the someone gave me a little background on how they obtained the knowledge that is being related to me and unlike Jeopardy it does not require it in the form of a question.

 

My prioritiy on post paint (as they are with post maintenance) are that the control surfaces are free and correct.

[Jerry 5TJ]

I had the M20C elevators reskinned recently and they were mass balanced after repainting, yes.  No changes required, but the mass and moment arms were measured.   There is a log entry to that effect. 

[cliffy]

Let's see. where to begin?

I pose questions to bring about thought and discussion on this and other forums.

I bring to the forum 46 years as an A&P and 13 years as a Mooney owner. I run into aircraft maintenance issues very often and a high percentage of them are brought about by the owner either not knowing or not caring about the maintenance. I have heard many times,"I take it in for an annual". unfortunately, that doesn't cover the owners responsibility as far as the FARs are concerned. One only has to read FAR 91.403. If it doesn't annoy anyone, I'll let them read it. Has anyone ever let an AD over run either time or date? I just had a C model that I discovered flies @200 hrs per year and yet the owner though all he had to do was 1 annual and the lubrication AD once a year. WRONG!.  So that is why I pose questions. I don't want to see anyone hurt and I don't want to see anyone get a violation.

I bring up the elevator bungees because it is unique to Mooneys and many times a misunderstood item on Mooneys. If your maintenance isn't done by someone informed about the system it will be missed. 

The elevators on a Mooney can not be removed and replaced "accurately" for correct throw angles unless they are re-rigged per Sec 6 of the Mooney Maintenance Manual.To do that you need some way of measuring throws at certain precise angle settings of the moving stabilizer in relation to the horizontal waterline of the fuselage. Once the stabilizer is set at 3 1/2 degrees airplane nose up the elevators need to be adjusted to a specific up elevator  degree setting in relation to the stabilizer (12 degrees on D models, 9 degrees on C models, 5 1/2 on F models, etc). This adjustment is done by the two nuts that hold on/in the springs in the elevator bungees. So you just can't mount the elevators on the hinges and tighten down on the bungees without using an elevator trim board to measure the angles correctly.

So, if you had your airplane repainted and the controls were removed and replaced AND they didn't have and use a Mooney trim board to reset the elevator angles they will not be correctly set. Now consider the allowable tolerances is in the order of 1 degree, they can't be set without the proper tools ON A MOONEY. Cs, Bs and Ps don't have this issue. 

[cliffy]

Let me just add for those who may need to know

I hold:

MEL ATP 20,000+ hrs Typed in B767, B757, B737, B727, A320, LrJet, CE500, MU2

As stated, 46 yrs A&P trained on B707, 720, 747, 727, DC8, DC9, DC10, CE500, numerous smaller a/c

I've lost too many friends in this business to ignorance or carelessness to not want to pass on what I know.

[scottfromiowa]

Thank you. THAT was awesome and I appreciate your sharing your knowledge.

[scottfromiowa]

As many painters likely do not have the travel boards and simply re-install like brand C, P & B what is the result of just re-installing on a Mooney? Many are obviously painted and are not falling out of the sky due to improper elevator install...why not? What is the likely result of improper installation? Is there a real concern with pitch to the point of loss of control from improper install?

[cliffy]

By Cs I was implying "Cessna" type airplanes. Their elevators can be removed and replaced without upsetting the control

throw angles by the way they are attached. Control angles relate to control authority. Control authority and response is a design parameter set at the factory to meet certification requirements. In general, too much authority can lead to an unstable flying a/c and too little authority can or may cause an unrecoverable condition upon a/c upset. There's a lot more to it but again the

tolerances are 1 degree either way so just by that it can be deduced that it is an important item to keep correct.

BTW, control rigging is supposed to be check at every annual/100 hr. Does your shop have the proper tools to do the check? Figure 6-4 in the Mooney Maintenance Manual. :-)

Just asking.

I have another question I'll pose in another thread.

[scottfromiowa]

I'll pose a question too. Has a Mooney ever had a catastrophic incident that related to the elevators being more than 1 degree off "correct" position after reinstall from a paint shop?

[scottfromiowa]

Daver328...That never gets old. Keep rolling it.

[scottfromiowa]

From one former CO to another Merry X-Mas. I would like that. Until then...

[Sabremech]

I have replaced an elevator on my bird not to long ago and it can be done without upsetting the springs/bungee. In Cliff Y's post he says removed and replaced, if that's the case then I would agree with him. If they are removed and reinstalled, which is most likely the norm during a paint job, then I don't necessarily agree with his statement. I'm not near my maint manual right now, but I suspect there's more flexibility than what is posted by Cliff Y.

 David

[isaacpr7]

What about ailerons for flaps? Do they have to be rigged checked when removed but not replaced as well?

[cliffy]

Flaps and ailerons are attached with Heim joints and can be removed without upsetting rigging.

Elevators can also be removed by removing bolts from the control horn through the elevators BUT most of the time

that I have seen they are removed by undoing the bungee nuts and springs and then the 4 hinge bolts each.

IF it was done by removing the control horns only then you'd be OK BUT which way was it done? Did you know enough to ask? Have they ever been removed before the paint job for any other reason (and where they then re-rigged)?

My point is NOT whether someone can come up with way to do it without re-rig but the fact that there are a lot of paint jobs done the incorrect way or no way to tell unless one was there and watched AND knew what they were looking for! I have found them (at least for me) up to 4 degrees out of spec. AND NO, they are not "falling out of the sky" because the rigging wasn't checked BUT they DO NOT meet TC specs and YOU don't know what the ramifications are. It's an attitude of either you're willing to make sure it's done correctly on YOUR airplane or you're not. Your choice!

Let's just bring up one more item to see how many want to debunk it. We have an annual requirement AND a 100hr requirement per an AD, to lube the airplane flight controls and landing gear rod ends, included in that AD is a requirement to swing the gear ANDmeasure the over center torque of the landing gear by using the required "special" tools. How many out there know for sure that their last annual or 100 AD was done using the special tools to measure torque? Does your mechanic even have them? Have you ever asked him? I know of shops that do Mooney annuals and don't have the special tools! Let's add to the mix checking proper flight control rigging at each annual per the factory 100 hr inspection guide, does your shop have the rigging boards to measure the control travel? If not, how do they comply with the annual check list AND yes they are required to follow the check list to do the annual. Anyone want to try and debunk that one?

There is one thread here that someone talks about doing landings with the trim all the way nose up and having an approach speed of 85 MPH. Either the plane is way out of rig or the flying technique is way wrong. I can speak on either issue but I won't.

It is interesting to me to see how many on this forum try to debunk an issue, take exception with the question without carefully reading the question, or try to find some esoteric way around it rather than taking it for what it was offered as, an issue you MIGHT want to look at if you are not familiar with it, so that you are more familiar with the maintenance issues on your airplane. I have found many owners (and not owner/A&Ps) to be interested in learning about their plane and its maintenance but on the other hand I have seen just as many that are ignorant of what is required, arrogant enough to say what is required does not apply to them or they figure they know more than the company that designed it. All one has to do is go through a full investigation by the FAA (no I haven't had the pleasure but friends have)to know what it feels like to have the feds ask, "so what makes you think you know more than the manufacturer". Whether it is how to comply with ADs, maintenance issues, who can LEGALLY work on your plane or what parts are installed on it (hardware store bolts and nuts for one) someone is always willing to skirt the edges.

Merry Christmas to all and I'm out of town for a while.

[aaronk25]

Not sure what you mean about the 85mph comment on a J full up trim is needed to have it trimmed correctly with full flaps at about 85mph. I normally don't trim it all the way to the stop as I just used some back pressure on the yoke. But my plane is rigged correctly and I'm not endorsing full aft trim technique but it's required if your not going to keep some back pressure when landing.

[Sabremech]

Hi Cliff Y,

I wouldn't call it debunk but rather question the all knowing authoritative tone the majority of your posts contain. If this is your idea of teaching owners about maintenance, I'd suggest a new approach.

David

[scottfromiowa]

There is teach and there is pontificate. I prefer teachers. I enjoy having fun (fun defined by me unfortunately for others). I like to understand why the rules are "the rules". That is the nature of laws/rules/regs. Black and white. Right and wrong. I understand the importance of knowledge and have learned a lot about maintaining/ensuring my plane is maintained...but I am not an A&P. If/when the time comes to answer that question..."You know better than the manufacturer?" I hope I can get through the process the best I can...

[rob]

You keep referring to this 100hour lubrication AD. Could you please specify which AD it is that calls for this?

Thanks!

[Marauder]

You keep referring to this 100hour lubrication AD. Could you please specify which AD it is that calls for this?

Thanks!

The Heim joints on the control rod ends amongst other things. 73-21-01

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/AOCADSearch/022EF974FDE32DBA86256A3B006FA1EA?OpenDocument

[rob]

Where does that say you have to lubricate every 100 hours? I read it as requiring at same interval as retraction test. 

[Marauder]

Where does that say you have to lubricate every 100 hours? I read it as requiring at same interval as retraction test.

"intervals not to exceed 12 calendar months from the last inspection or 100 hours time in service from the last inspection, whichever comes first, lubricate all flight control systems and landing gear system rod end bearings with a silicone spray lubricant or with an FAA approved equivalent lubricant."

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[rob]

Interesting, skipped right past that. Thanks!

[Marauder]

I have seen that AD listed in my logs (and the one on the ignition switch) for the past 23 years, so I finally went out and read them one day.

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[Marauder]

Cliff -- when you get back. Do you think you could work up a checklist of what to look for / ask about when considering a paint shop? I think the information is in the posts you made, but it would be good to have a summary list for those of us contemplating a paint shop at some point.

To answer your questions (at least some of them); yes I know my mechanic has the story boards and he has the landing gear load testing equipment. I agree there are owners who are trusting of their mechanic to a fault. Not so much for me. It is me and my family in the plane, not him and his...

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[cliffy]

I'm not back yet but I will post an article I wrote for those who might be interested.

ARE YOU SHAKING YOUR TAIL?

How One Question Can Lead to another and another and another-

I received a call from a local shop asking me to look at a Mooney that was in the shop. They are not Mooney experts and much to their credit, they know their limitations. I got to the airport and walked around the Mooney to the tail where the other mechanics were standing. One of them asked, “Is this normal?” and proceeded to move the tip of the tail up and down which was accompanied by a loud “click” “clunk” with the tip moving almost a half inch in both up and down and fore and aft directions. Hmmmmmm!

Of course, all of us know what causes this, right?

They had the tail cover plates off and I went over and held my finger on the tail mount bolts and then had them move the tail again. Sure enough, I could feel movement in the bolt bushing area. On closer examination I could see a gray discoloration around the bolt head area and no evidence of any lubrication in the area. In fact everything I looked at in the tail area showed no evidence of lubrication!

I suggested that they not fly it until the wear was repaired and I asked (here’s the first question) “who does your maintenance?” The airplane is not based here year round. I was told that a local shop in another state has done the annual for several years. After a little chit chat I mentioned that I felt that the airplane had not been properly lubricated for some time and I asked (here’s question number 2) “How much do you fly this every year?” The answer, “Somewhere around 200 hours a year.” Hmmmmmmmm!

I then asked (here’s question number 3), do you do the lubrication AD every 100 hours”

The answer, “We do an annual every year.” Hmmmmmmmm!

Next question (here’s number 4), do you know about the lubrication AD? “No, our mechanic does an annual every year.” Hmmmmmmm!

I’m going to digress a little here to say that this is not the first time I have run into aircraft owners who, for what ever reason, do not know what THEIR legal requirements are when it comes to maintenance on their airplane.

To many owners, the mere fact that they have an annual done every year is all that they are responsible for on the maintenance of the plane. Unfortunately that’s not completely correct. Let me quote from FAR Part 91.405-

§91.405 Maintenance required.

Each owner or operator of an aircraft—

(a) Shall have that aircraft inspected as prescribed in subpart E of this part and shall between required inspections, except as provided in paragraph © of this section, have discrepancies repaired as prescribed in part 43 of this chapter;

( Shall ensure that maintenance personnel make appropriate entries in the aircraft maintenance records indicating the aircraft has been approved for return to service;

© Shall have any inoperative instrument or item of equipment, permitted to be inoperative by §91.213(d)(2) of this part, repaired, replaced, removed, or inspected at the next required inspection; and

(d) When listed discrepancies include inoperative instruments or equipment, shall ensure that a placard has been installed as required by §43.11 of this chapter.

If we go back one paragraph to 91.403 it states-

91.403 General.

(a) The owner or operator of an aircraft is primarily responsible for maintaining that aircraft in an airworthy condition, including compliance with part 39 of this chapter.

So as we can see, you as the owner, have more responsibility than just bringing your airplane in for an annual every year. YOU have to manage the maintenance all year long. If you have a recurring AD, like our lubrication AD 73-21-01, and you fly over 100 hours in the year, YOU have to make sure that the AD is done. Your maintenance shop will probably NOT know you are over 100 hours in the year until he sees your plane at the next annual. It’s your responsibility to tell him when the AD is due between annuals. This goes for all recurring ADs, so keep your eyes open.

Back to our story: After discussing how important lubrication is on a Mooney and how he needed to address the tail bolt issues, he mentioned that they had to jump start the airplane with cables even though they had an external power plug. I asked (here’s question number 5) “Why?” Because the aux plug doesn’t work was the answer. Hmmmmmmm!

It was then volunteered that the airplane had had a gear failure and had been repaired but they thought that the gear doors didn’t close all the way! Hmmmmmm!

The owner was convinced enough to ground the airplane and start working on the tail hinge. After 8 shop hours of trying to get the bolts out, a screw press was made to carefully push out the bolts. They were completely dry, rusty and worn. New bolts were tried in the holes and the bushings turned out to be good. Only the bolts and the missing washers on those bolts were needed to bring it back to no slop! Hmmmmmm!

The owner then took all the panels off the plane and started to lube everything movable, as it should have been done every 100 hours.

Having my Maintenance Manual handy I showed them the electrical schematic for the external power plug. In trouble shooting it, I found that the external power relay was missing the ground/diode wire from the coil to ground. Easy fix, just no one knew how to fix it. Hmmmmmm!

Now to the gear problems-

With the plane on jacks and the belly open I went to the nose gear first. Fore and aft, left and right lots of play in the vertical bushings and bolt. Twist the tire and way too much play in the steering linkage. In checking the mains I find a little play in the retract linkage but not too bad. OK, lets suck’m up and see what that holds for us.

Sure enough, the mains don’t go all the way up. Short by 2 inches, gear doors not flush at all. And this is just a few months out of an annual inspection! Well, let’s see what the manual extension holds for us- oopps! It doesn’t go down! Turns out that the release lever works but the crank handle won’t crank!

So, let’s recap what I find on the gear:

1) Nose gear is way worn in the steering linkage and pivot bolt/bushings.

2) Main wheels don’t retract properly.

3) Emergency extension doesn’t work.

4) One frozen Heim joint on the retract bars for the nose gear.

So, the owner now has a new list of items to fix before he can go fly again.

As you can see by this long litany, one question can and will lead to many others when it is noted that there are problems with your airplane. It should be blatantly obvious by now that a maintenance shop has to have specific knowledge of Mooney maintenance practices to be able to do a competent job. The owner “thought” he was getting good maintenance all these years BUT?

And, as an owner, you can’t just live with your head buried in the sand when it comes to aircraft maintenance. Remember, YOU are the one in the airplane and as the owner; you have the legal responsibility to maintain your airplane properly. The more you know, the safer you will be.