M20C rigging problem

[Sabremech]

On 4/3/2022 at 8:05 PM, EricJ said:

He's saying it's an issue on the flaps.   The M20J manual says to align the flaps with the ailerons.

For the stab put the digital level on the top and the bottom and split the difference for the reference.

Who’s saying it’s an issue with the flaps? The OP doesn’t know what causing the problem. 

 

17 hours ago, EricJ said:

Sure when they're available, but usually they're not.   Even the efforts here to duplicate them haven't been very successful in providing options for all models.

Just like when a material specified is no longer available (and AC43.13 doesn't give much guidance on that), when a tool isn't available you may need to do something else.   If you understand geometry and trig and how to make measurements, it's definitely possible to do it without the boards, and lots of shops commonly do and have done for a long time.

In my case I learned the other methods in A&P school, where out of a fleet of more than a dozen different types of airplanes we had boards for one.   So we were taught how to do it with other methods on a bunch of different airplanes.   The one airplane we had boards for was a Grumman Yankee, so I took the time to try three different methods: boards, protractor, and digital level, on that airplane.   The digital level was the most accurate and repeatable.   The boards were actually kinda sloppy in comparison in my opinion, and subject to a lot of positioning errors.  I found I could make the boards say what I wanted within a particular range.

So if I ever get any grief about it I'll point the FAA to my approved A&P school after showing how the other (commonly practiced) measurements can provide a more accurate solution than boards might.   I can probably leverage my 30+ years of engineering experience there, too, for drawings and measurement and tolerance assessment.   It's kinda like how MMO isn't approved to be used anywhere near an airplane, but maintainers have been using it for decades.   This is how "common practice" often gets cited, even by the FAA.   If an airplane crashed that got a cylinder rehabbed with MMO or was running it in their oil or fuel, I doubt the FAA would consider that a cause, since it's been done safely for decades.   Likewise rigging without boards when they're not available. 

If there’s a fatal accident and it can be directly or indirectly attributed to improper rigging, you have no leg to stand on as the AP who did it without the correct tooling. Do it as you see fit, but it’s not IAW the maintenance manual procedure. I’ll stick with what I’ve learned and practiced as an AP/IA for the last 30+ years. It’s worked well for me and my customers and I don’t lose sleep as to whether I did my best. 
 

[EricJ]

3 hours ago, Sabremech said:

Who’s saying it’s an issue with the flaps? The OP doesn’t know what causing the problem. 

The post you were referring to at the time stated it was with reference to flaps.

3 hours ago, Sabremech said:

If there’s a fatal accident and it can be directly or indirectly attributed to improper rigging, you have no leg to stand on as the AP who did it without the correct tooling. Do it as you see fit, but it’s not IAW the maintenance manual procedure. I’ll stick with what I’ve learned and practiced as an AP/IA for the last 30+ years. It’s worked well for me and my customers and I don’t lose sleep as to whether I did my best. 
 

If it's improperly rigged with boards there'll be scrutiny, too, and rightly so.    If it's properly rigged using alternative common practice methods how would that cause an issue?
 

[Sabremech]

7 hours ago, EricJ said:

The post you were referring to at the time stated it was with reference to flaps.

If it's improperly rigged with boards there'll be scrutiny, too, and rightly so.    If it's properly rigged using alternative common practice methods how would that cause an issue?
 

Why do you advocate on a public forum for someone to not follow the maintenance manual procedures? You might use the PM feature for that kind of advice. The FAA along with Mooney monitor these boards and anything you post here may be used for an investigation. I do see from the FAA database you do hold that certificate. How long have you been an A&P? 
 

Good luck with pointing the FAA to your approved A&P school. I suspect with that attitude they’ll request you return for remedial training. 

[EricJ]

2 hours ago, Sabremech said:

Why do you advocate on a public forum for someone to not follow the maintenance manual procedures? You might use the PM feature for that kind of advice. The FAA along with Mooney monitor these boards and anything you post here may be used for an investigation. I do see from the FAA database you do hold that certificate. How long have you been an A&P? 
 

Good luck with pointing the FAA to your approved A&P school. I suspect with that attitude they’ll request you return for remedial training. 

Evidently you've missed the Big Point, which is that most maintainers and shops don't have access to, and cannot get, travel boards.    When they're not available, which is the case for many/most, other methods are used.   If you think all of the paint shops and other maintainers that do rigging and inspect rigging all have travel boards, you are mistaken.

For those who have them for all of the appropriate models of aircraft serviced, and you are apparently so blessed, then by all means use them as you see fit.   But for the many who do not have access, evidently many affected shops feel it is not practical to ground an airplane because of the lack of a tool when other methods that have been in common use for decades will do the job.

If you want the phone number for the A&P school that I went to so that you can call and educate them, just ask.   They have a close relationship with the FAA and host the local IA seminars, which we were required to attend when I went there.   You might be surprised what the FSDO people actually find practical when you hear it directly from them.

[chriscalandro]

I don’t think Mooney is watching anything other than their email inbox hoping someone has responded to their “business for sale” ad. 

[PT20J]

It doesn't seem to me that there is any magic to travel boards. They make the job easier. The only really special thing they do is define the zero reference point which is not that hard to figure out. After that, angles are angles. The TCDS only lists angles. 

The airplane was rigged correctly when it left the factory. Unless it has been wrecked, it's pretty hard to see why it would be out of rig unless someone has been messing with it. I'd wager that the biggest problem is not people making changes without travel boards, but rather making changes when they don't know what they are doing. I've seen all sorts of silly things suggested on this board.

My airplane left the factory 28 years ago. According to the log books the only thing that has been adjusted is the right flap. It flies straight and I checked everything with a digital level and it is within specs.

Skip

 

[carusoam]

The most amazing thing I experienced in my old M20C… was it’s well rigged status…. 

Untouched for 45years…

The wing leveler was inop during my ownership…

 

Somewhere in the middle of any flight in smooth air… 

The L/R weight balance was centered enough…

The pilot can use weight shifting techniques inside the cabin…

To maintain following the magenta line… (black LCD line on a portable Garmin GPS at the time…)

Distance from the centerline was WAAS measured and displayed in feet…

Turning left… the pilot needs to be swift. There isn’t much room to shift to the left side of the seat…

Having Ceis fuel level instruments and digital displays were not required…. But sure woukd be nice to have!

 

My M20C really impressed me…

Go Mooney!

Best regards,

-a-

[Sabremech]

10 hours ago, EricJ said:

Evidently you've missed the Big Point, which is that most maintainers and shops don't have access to, and cannot get, travel boards.    When they're not available, which is the case for many/most, other methods are used.   If you think all of the paint shops and other maintainers that do rigging and inspect rigging all have travel boards, you are mistaken.

For those who have them for all of the appropriate models of aircraft serviced, and you are apparently so blessed, then by all means use them as you see fit.   But for the many who do not have access, evidently many affected shops feel it is not practical to ground an airplane because of the lack of a tool when other methods that have been in common use for decades will do the job.

If you want the phone number for the A&P school that I went to so that you can call and educate them, just ask.   They have a close relationship with the FAA and host the local IA seminars, which we were required to attend when I went there.   You might be surprised what the FSDO people actually find practical when you hear it directly from them.

Big point missed? Nope! Do post up how many years you’ve been an A&P! 

[N201MKTurbo]

I'm pretty sure if there were digital levels in the 60s there would be no travel boards.

[Sabremech]

42 minutes ago, N201MKTurbo said:

I'm pretty sure if there were digital levels in the 60s there would be no travel boards.

I’ll have to disagree once again. They are both quite useful. The travel boards reduce the risk for error. It’s interesting to note that travel boards are still widely used in the corporate aviation. I’ve had to rent them a few times over the years. Also quite nice to have them available for the Mooney as it made re-rigging stab trim a breeze. 

[N201MKTurbo]

1 hour ago, Sabremech said:

I’ll have to disagree once again. They are both quite useful. The travel boards reduce the risk for error. It’s interesting to note that travel boards are still widely used in the corporate aviation. I’ve had to rent them a few times over the years. Also quite nice to have them available for the Mooney as it made re-rigging stab trim a breeze. 

I will agree that they can reduce error. To do it with a digital level you need to do math. When you do math you can make mistakes. And yes, if you were doing it in a production environment, travel boards would be quicker to use.

But on the flip side, if you know what you are doing, and don't have travel boards, you can do it all with a digital level. Except setting the rudder stops. you need a digital compass for that.

Edited April 6, 2022 by N201MKTurbo

[Sabremech]

39 minutes ago, N201MKTurbo said:

I will agree that they can reduce error. To do it with a digital level you need to do math. When you do math you can make mistakes. And yes, if you were doing it in a production environment, travel boards would be quicker to use.

But on the flip side, if you know what you are doing, and don't have travel boards, you can do it all with a digital level. Except setting the rudder stops. you need a digital compass for that.

Yep, agreed. What I found most disturbing was the advice to an owner who’s not an A&P and didn’t know what travel boards are to deviate from the maintenance manual on a public forum. 
Thanks,

[cliffy]

Do Cessna 150s have/use travel boards to check throws every year? I don't know as I haven't worked on one of those in 40 years.

If not how do they get checked to the numbers in the TCDS? 

[EricJ]

39 minutes ago, Sabremech said:

Yep, agreed. What I found most disturbing was the advice to an owner who’s not an A&P and didn’t know what travel boards are to deviate from the maintenance manual on a public forum. 
Thanks,

Ah, so part of the problem is that you've misunderstood the conversation.   That explains it.

[Sabremech]

14 minutes ago, EricJ said:

Ah, so part of the problem is that you've misunderstood the conversation.   That explains it.

Nope, I understand quite well what you’re professing here and to the OP!

How long have you been an A&P? Still waiting! 

Edited April 6, 2022 by Sabremech

[EricJ]

Just now, Sabremech said:

Nope, I understand quite well what you’re professing here and to the OP!

Evidently you don't.  But then you agreed with @N201MKTurbo when he said the same thing, so it's hard to say.

[ShuRugal]

This has devolved into the weirdest pissing contest I've seen around here.

Sent from my Pixel 3a using Tapatalk

[Sabremech]

1 hour ago, EricJ said:

Evidently you don't.  But then you agreed with @N201MKTurbo when he said the same thing, so it's hard to say.

Give it a rest. How long have you been an A&P? Afraid to put that out in public! 

[Sabremech]

1 hour ago, ShuRugal said:

This has devolved into the weirdest pissing contest I've seen around here.

Sent from my Pixel 3a using Tapatalk
 

So you believe it’s ok to recommend deviating from maintenance manuals on a public forum? That’s the heart of the matter. Not a pissi*g contest at all. 

[ShuRugal]

So you believe it’s ok to recommend deviating from maintenance manuals on a public forum? That’s the heart of the matter. Not a pissi*g contest at all. 

If the maintenance manual says that the only acceptable method requires a spoon-fed badger named "Alfred" to perform the work, but the industry has been using other techniques for decades because Alfred died, and was never the only qualified badger in the first place, then the manual is wrong.

Sent from my Pixel 3a using Tapatalk

[cliffy]

If Mooney MM gives out a 100 hr Inspection sheet for that and annuals yet many perform and  Annual to Pt 43 how does that figure into this discussion?

Pt 43 is not in the MM yet the FAA allows an annual to be signed off without using the MM form and scope? 

Now there is the requirement for all Repair stations to sign off all work with a notation of the affected MM section- "per 32-25-33" or some such notation but where that "requirement" is not pressed on to non Repair Station A&Ps out in the field. Most FAA types would "like" a reference to the appropriate MM section for all work performed but it is NOT a requirement outside a Repair Station environment (121,135, 125, included) . 

[EricJ]

3 hours ago, Sabremech said:

Give it a rest. How long have you been an A&P? Afraid to put that out in public! 

Given the signature block on my posts and the fact that I posted about it here about starting the school and when I got both my A and P ratings about a year apart, I've no idea what you're on about.

I did go dig out my original OJT logbook, though, and my first aircraft maintenance credit was assisting with a 100-hour inspection on a Cessna 150 on 1 September, 1974.

[Guest]

8 hours ago, N201MKTurbo said:

I'm pretty sure if there were digital levels in the 60s there would be no travel boards.

For the purposes of flight control rigging, I’m not sure that a digital level is any better than a bubble protractor or a propeller protractor or a travel board.  They might be simpler to read for those who can’t work other tools.  Look at a digital caliper versus a vernier caliper, most of us older guys can read both, where as the younger ones can’t read a vernier or a micrometer.

Clarence

[Guest]

5 hours ago, cliffy said:

Do Cessna 150s have/use travel boards to check throws every year? I don't know as I haven't worked on one of those in 40 years.

If not how do they get checked to the numbers in the TCDS? 

Cessna uses the SE716 inclinometer, suction cup it to the flight control, zero the scale under the pointer, move the control up and down, read the number under the pointer.  Rudder travel is usually done by measurement from a fixed and known point.

Clarence

[cliffy]

That looks like a prop protractor in a different form (they all work the same, gravity is always perpendicular to the surface of the earth)

Never worked with one of those above but have used a bubble protractor a time or two  Works the same way.   :-)