Who can do Rigging?

WDD

WDD

Final Approach
PoA Supporter
Joined
Oct 16, 2019
Messages
6,341
Location
Atlanta / Marietta
Display Name
Display name:
Vintage Snazzy (so my adult children say)
If I wanted to get rigging checked and re rigged, would your standard A&P be able to do that, or does that require a special shop to get it dialed in? I’m finding I need nose down trim and left trim in cruise, and want it checked out.
 
You will want to specify what configuration you want it ring for.

Fuel level, passengers, right seat, or rear, baggage etc.

Flying perfectly would just someone in the left seat is one thing, but then

he put some in the right seat. It’ll change everything.
 
Hang 4 said:
Assume from your avatar, you have a Cessna? Any A&P can follow the service procedure, but this guy takes it to the next level.

https://www.cessnarigging.com/
Click to expand...

I reached out to John a couple months back to do my plane and he was scheduled out to the end of the year and reluctant at that time to schedule more work. I reached out to him recently but have not heard back yet.
 
WDD said:
Hoping to find an expert like that a bit closer.
Click to expand...
Any mechanic is capable, but the key is their experience and what procedure they use. Its not really a technical task per say, just takes patience and to follow the complete process with no shortcuts.

However, all proper rigging starts with a control system that meets spec: wear within limits, clean, and lubed. If your system is not to spec, then usually the results will not be spec either.

A good place to start is at your next annual when everything is open and review, clean, and lube every flight control item per the book. Or if this is something you want done sooner, then open things up and check it. Once you know the system is to spec, then have it rigged per the book.

What's your current mechanic input on this?

If you have access to your specific maintenance manual, perhaps read up on it to give you a better understanding on it. Any questions post here?
 
I found most older Cessnas out of rig. Mechanics too often shoot from the hip on this stuff, and over the years an airplane just gets worse as subsequent mechanics change stuff to try to fix previous misrigging instead of reading the manuals and starting over and doing it right. The dumbest is rigging one aileron low to fix a wing-heavy issue; it does not work. The airflow will push the low aileron up until the other is pushed down to a similar low angle, and the wing-heaviness will still be there, but with an aggravated stall and lower cruising speed.

Read the manuals and do exactly what they say.
 
455 Bravo Uniform said:
I reached out to John a couple months back to do my plane and he was scheduled out to the end of the year and reluctant at that time to schedule more work. I reached out to him recently but have not heard back yet.
Click to expand...
I also tried reaching out to John to schedule a rigging job, either he's booked solid, not taking any new customers or a bunch of reasons. Finally gave up and I'm now trying to work with another rigging guy at K81 in KS
 
Larry Korona said:
I also tried reaching out to John to schedule a rigging job, either he's booked solid, not taking any new customers or a bunch of reasons. Finally gave up and I'm now trying to work with another rigging guy at K81 in KS
Click to expand...
Let me know how it goes, please.
 
How do you find Rigging guys?
 
There are actually things you or your Tech can check but you cannot

adjust.Everyone will have a different starting point and sequence on

this but this is my approach: ( my recall of 150 Manual.)

1. Determine if Flaps UP is correct . This will also provide the

NEUTRAL of Ailerons. If this is not correct you have likely found

the problem and proceed to rig Flaps then Ailerons per SM.

This is significant in cruise.

Note that it is quite common on Cessnas to find sagging Panel Shock Mounts.

This can cause the T & B Ball to be in error.


If NEUTRAL is correct you may have bigger issues. When

Wings are repaired it is ESSENTIAL that wing twist or “ wash-out”

be verified. There is a simple procedure in the SM using a level

and grinding 3 scrap bolts to particular lengths. This can be

checked with zero disassembly. If incorrect; the fix is not easy.


2. If Flaps and Ailerons have correct NEUTRAL position and a check

flight reveals a wing- heavy condition it’s likely the “Eccentrics”

at the Rear Spar Attach require adjustment.


NOT A ONE PERSON JOB

Generally it’s a 3 person task for a few minutes for the

actual adjustment. One front,one rear and an observer to

coordinate. If not done simultaneously Spar Damage will result.

This may affect cable tension.o


3. Control Surface Travel should not be a factor in cruise but is

important when maneuvering. When ailerons are adjusted it’s

Important the Bellcranks are centered per SM. Failure to do

will give odd roll/turn characteristics even if NEUTRAL is right.


3. Check Trim Indicator - With Elevator and Tab both in NEUTRAL

what is the indication?


Again; you are checking to verify rigging per SM but a Tech must

adjust.



Hope this helps
 
Last edited:
Magman said:
3. Check Trim Indicator - With Elevator and Tab both in NEUTRAL

what is the indication?
Click to expand...
In some of the 172s the tab will be up a few degrees with the trim in the takeoff position. Adjusting the system to have the tab neutral at the T/O indication will result in having to rapidly trim nose-down after takeoff. Pilots hate that. The manual gives the rigging procedure.
 
WDD said:
If I wanted to get rigging checked and re rigged, would your standard A&P be able to do that, or does that require a special shop to get it dialed in? I’m finding I need nose down trim and left trim in cruise, and want it checked out.
Click to expand...

I have a rather low opinion of standard APs these days. Most APs with experience are have an IA and I would stick with that.
 
Clip4 said:
I have a rather low opinion of standard APs these days. Most APs with experience are have an IA and I would stick with that.


Several A&P’s I know are quite competent. They tend to hate “ paperwork

and would rather focus on a few large jobs rather than multiple inspections.
Click to expand...
 
Clip4 said:
Most APs with experience are have an IA and I would stick with that.
Click to expand...
Not really. If you were talking about IAs prior to 2000 I'd agree, but after that its not always an indicator of "experience" or knowledge. In todays the better way to vet a mechanic is for you to become more knowledgeable on what you need to have performed and engage in a discussion with them. Then make your decision.
 
Must be a popular topic. I found a shop in TN that specializes in rigging. They are taking appointments - one year out. No, not kidding. The shop in TX, John at Cessna Rigging according to posts above isn’t even returning calls.

Yikes - and I thought avionics shops were backed up.
 
IMHO Cessnas and Pipers are easy to rig. Just follow the SM. There are

only so many adjustment points. What is the “ magic”? Is this one of those

“Tech X can change the oil better than anyone else can change the oil!”


As I stated earlier all bets off with improper repair. I have a guy now that

wants a 337 RTS signed w/o checking wash- out.


Stearmans, WACO’s and even the Ercoupe are most challenging.


Rig to book spec.

Adjust after Test Flight.
 
Sounds possible with a good A&P. I’m becoming smarter about working with mechanics though. Some are good at xyz, but for abc you want to go somewhere else.

For example I declined working with an avionics shop about a GFC 500 autopilot install because the guy has never done one. But he’s been great with other things.

So I’m trying to find a shop that has done rigging and done it well, or if they don’t do many but is so particular they are slow but do it right.
 
The actual rigging is quite easy.

What complicates it is gaining access to some turnbuckles.

Often someone tries to make adjustments w/o using the

affected turnbuckles.

Auto -pilots can be affected too.
 
Yep then trying to redo the safety wires with only one hand is tough.
 
Older aircraft, that do not use dynafocal mounts for the engine(and maybe some that do use them) should check the thrust line of the engine before making rig changes. The weight of the engine, over many decades may alter the thrust line in multiple axis', making for interesting changes in how the plane goes through the air under power. Tilting down at the nose is very common, and for some reason, tilting to the left a few deg is commonly found. In my personal plane, I can rotate the engine mounts every few years to maintain a pretty accurate thrust line. Most planes would need new engine mounts, but may be able to be rotated, or even reversed(front to back), whatever works.
 
Barrett50 said:
In my personal plane, I can rotate the engine mounts every few years to maintain a pretty accurate thrust line. Most planes would need new engine mounts, but may be able to be rotated, or even reversed(front to back), whatever works.
Click to expand...
Mounts should be replaced, not rotated. Their rubber gets hardened and sometimes cracked. I have found mounts sagging so badly that the engine's mount lugs are banging on the mount bolts. That can get ugly soon enough.

Even the Dynafocal mounts sag. The mount sets are designed to resist that, with those in compression being firmer that their partners. Upper rears and lower fronts are the stiffer ones. Even at that I have found them compressed and set so badly that I can lift the prop and hear them clunking against the engine mount sockets. No tension on them anymore.
 
You adjust the thrust line of the engine with engine mounts???
 
WDD said:
You adjust the thrust line of the engine with engine mounts???
Click to expand...
Not exactly. But worn engine elastomerics can alter the thrustline. Normally the thrustline is set by the design angles of the metal engine assy or in the case of aftermarket thrustline mods, shims installed at the firewall where the metal mount is attached.
 
I agree with the comments of Dan and Bell.

Recently met a Tripacer where conical mounts had compressed and

allowed the Engine to sag and contact the Steel Mount.

Shock Mounts on 182’s have the beam type rear carrying very little load.

The forward carries 1/2 the engine weight and the weight of the Prop.

The forward mounts tend to compress and allow the Engine to sag.

On early years this resulted in the Intake Duct being rubbed by the

Oil Pan. Not good!
 
Bell206 said:
Any mechanic is capable, but the key is their experience and what procedure they use. Its not really a technical task per say, just takes patience and to follow the complete process with no shortcuts.

However, all proper rigging starts with a control system that meets spec: wear within limits, clean, and lubed. If your system is not to spec, then usually the results will not be spec either.

A good place to start is at your next annual when everything is open and review, clean, and lube every flight control item per the book. Or if this is something you want done sooner, then open things up and check it. Once you know the system is to spec, then have it rigged per the book.

What's your current mechanic input on this?

If you have access to your specific maintenance manual, perhaps read up on it to give you a better understanding on it. Any questions post here?
Click to expand...

"Any mechanic is capable"...... I have doubts of that based on my experience flying rental aircraft.....
that said I do understand that it's likely more a result of a lack of desire from the owners to have it done...​
Still, I'd venture to guess that they all "should be" but many aren't


thinking this through and based on comments here, I'd guess that many/most aircraft flying are mis-rigged as a result of partial efforts and band-aid tweaks by well-intentioned A&P's
I've seen things like this in many areas though my career as a mechanical engineer (non-aviation stuff).
The example that comes to my mind often is lug nuts on a car. Most folks would say that any mechanic could properly change a tire, right?
I grew up turning wrenches. Small engines, small appliance repair, cars, tractors, etc... reading and following maintenance manuals for torque specs, etc... I knew how to change a tire. Later I went to college for a drafting and design degree, followed by a Mech E degree. Took extra courses in machine design which included threaded fastener stuff, etc... I knew how to "properly size and design" a threaded fastener system. My first job out of college had me doing some work with threaded fastener inspection, NDT work, and such
OK, I knew a little something about changing a tire.
A couple years after school I sat through a day-long threaded fastener course at work. It was put on by some engineers from the company that supplied threaded fasteners to the paper mill I worked for. The class was targeted at our millwrights and other maintenance folks. My eyes were opened to the concept of "you don't know what you don't know". I was blown away by how much I did not know about properly torquing a lug nut!

it seems like a "done correctly" rigging job would be a very involved thing. A whole-aircraft alignment restoration in a way...
it would need to START with inspection/replacement of things like engine mounts and panel mounts, frames, etc.
probably followed (or maybe preceded by) inspection of proper structural alignment (wing washout and positioning, fuse and spar damage/twist, etc..)
then followed by a very methodical point-to-point adjustment based on type.. such as flap, then ailerons, then... in a specific order, not out of order.
 
Brad W said:
it seems like a "done correctly" rigging job would be a very involved thing. A whole-aircraft alignment restoration in a way...
Click to expand...
Not really. But it does take some disassembly and following the book procedure in its entirety which includes checking the serviceability of the control system.

Brad W said:
I'd guess that many/most aircraft flying are mis-rigged as a result of partial efforts and band-aid tweaks by well-intentioned A&P's
Click to expand...
Yes, plus performing a rigging "check" vs performing a rigging process and the owner requests to keep things "simple."
 
I guess my point was....and this based on assumptions since I haven't read any example procedures
I'm doubting that most procedures for rigging get into the weeds of checking motor mounts, panel mounts, panel and Turn Coordinator alignment, checking structural alignment, etc.... which it seems all pretty much need to be checked before any control surface rigging is going to be "correct"
I suppose they could be thought of as two different things.... but seems like it's all part of one "system"
 
Brad W said:
I guess my point was....and this based on assumptions since I haven't read any example procedures
I'm doubting that most procedures for rigging get into the weeds of checking motor mounts, panel mounts, panel and Turn Coordinator alignment, checking structural alignment, etc.... which it seems all pretty much need to be checked before any control surface rigging is going to be "correct"
I suppose they could be thought of as two different things.... but seems like it's all part of one "system"
Click to expand...
All that stuff is on the manufacturer's inspection checklists and/or in the manuals. The holes in the panel for the screws that retain the attitude indicator and turn coordinator are slotted, and the mechanic is supposed to make sure the instrument is level with the airframe, as measured according to manual instructions.

If the airframe hasn't been in an accident or severe turbulence, it should be as straight as it came from the factory. Wing incidence is easy enough to check. Most rigging problems, 99% of them, are due to previous mechanics not reading and following the instructions in the manual.
 
I working up the idea that I’ll have my local mechanic check/ re rig things per the book as a stop gap, get things better. Make an appointment a year out to get the “rigging guru” to do the precise rigging.
 
Brad W said:
which it seems all pretty much need to be checked before any control surface rigging is going to be "correct"
Click to expand...
Not in my view or experience. Each system is independent and while one system can influence other systems the goal is to fix the broken system and not mask the problem by “fixing” the wrong system. And since most “rigging” issues start with a pilot discrepancy, which system I would troubleshoot first will depend on how that disc is described and felt by the pilot. If that makes sense.
 
I want to follow up and report on the rigging services that Deason Aircraft Services provided to me today on my C172. I was very pleased with their capabilities and knowledge, I highly recommend them. First thing the did is ask me to describe how the plane flew and any issues that I have experienced. Then they carefully examined the plane, checking all the control surfaces and wing alignment with all kinds of fixtures. Then they had their pilot fly the plane with me in the co-pilot's seat. We flew for a good half hour with then taking photos and notes. After landing the went to work adjusting. Turned out to be a super simple adjustment then back up for another flight to confirm. Excellent job, and to top it off, because it was just a simple fix, no charge for their time!

deasonaircraft.com

Small Aircraft Repair & Maintenance in Kansas | Deason Aircraft Services

With over 45+ years in the aircraft repair field, you can trust Deason Aircraft Services, Inc. to carry out any aircraft repair needed.
deasonaircraft.com deasonaircraft.com


IMG_6312.jpeg
 
The pic shows usage of the simple fixture used to check for proper wing

twist or “ wash-out” per Cessna SM.


Easily made and used but IMPORTANT!
 
Is there an online source or link to the service manual for proper rigging steps and specs? Or does one need a paper shop manual or pay for a PDF download?
 
455 Bravo Uniform said:
Is there an online source or link to the service manual for proper rigging steps and specs? Or does one need a paper shop manual or pay for a PDF download?
Click to expand...
There are some free ones online. Just search for "Cessna 172 service manual" or whatever airplane you have, and see what comes up. If they show as a .pdf, try one. Rigging will be under the various chapters of flight controls, or wings, for washout. and incidence.
 
Cherokees and Cessnas are fairly easy to rig and most experienced Techs can do the tasks. However; even the best will need the required fixtures and information to do it correctly. A shop that works on Cessnas in unlikely to have the fixtures on hand for a Cherokee or Grumman. In some cases; the SM details how they can be made. Some Type Clubs may have loaners too.
If you want correct results you have to start with correct equipment and procedures. You may pay for the Tech’s education but it may be better than waiting a year!
 
You must log in or register to reply here.
Back
Top