Aircraft rigging.

Dave Siciliano

Dave Siciliano

Final Approach
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Dave Siciliano
Brought 24Q up to Glen Biggs to have him look at the rigging of the aircraft. While 24Q has been a great plane, it has seemed a little slower than it could be and the rudder trim seemed to be different than any A-36 I'd flown before. When George Braly at GAMI flew it, he agreed it could benefit from having a rigging guy look it over and try to make some adjustments.
Today, one of Glen's folks and I discussed what was going on. They test flew the plane last week and adjusted one of the wings. They'll test fly if again and make some more adjustements. We'll see how much good they do.

Dave
 
This ought to be interesting. I'm looking forward to hearing about what they find.

What did they adjust with the wing? Its actual attachment or something else, like flight control rigging?
 
RotaryWingBob said:
This ought to be interesting. I'm looking forward to hearing about what they find.

What did they adjust with the wing? Its actual attachment or something else, like flight control rigging?
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They explained that of the four attachment bolts on the A-36, they could move the wing up to 3/8s of an inch. I would assume angle of attack, but didn't ask (unfortunatley, I was on the way somewhere and had to cut the call short). He said they would probably change aileron trim and maybe rudder. Guess we'll see.

Dave
 
RotaryWingBob said:
This ought to be interesting. I'm looking forward to hearing about what they find.

What did they adjust with the wing? Its actual attachment or something else, like flight control rigging?
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On a Bonanza (or Baron/Travel Air) the wing pivot on the front bolt and the rear bolt hole is slotted (actually arc'd) so each wing can be set at a different angle relative to the fuselage. Often times someone extends one flap a little bit to compensate for a "heavy" wing as this is much easier to accomplish than the proper adjustment of the wing. Also it's fairly common for wings to be adjusted w/o the rigging tools leaving both at the wrong angle. And given that a small fraction of a degree makes a noticeable differnce IIRC, the adjustment is tricky to say the least.
 
lancefisher said:
Often times someone extends one flap a little bit to compensate for a "heavy" wing as this is much easier to accomplish than the proper adjustment of the wing.
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Lance, this describes my plane perfectly. One flap down a little. Also, the aileron trim didn't seem correct. Rudder had the tab way to the left. Took full right trim on the yaw dampener in cruise flight a lot.


I'm really looking forward to seeing what Glen can get done. A lot of guys just swear by him around here. George Braly flew the plane as did Tim at GAMI. They called Glen and discussed what they thought was going on.


Can't really ask for much more than that. They pick up stuff I don't even notice.

Dave
 
RotaryWingBob said:
What did they adjust with the wing? Its actual attachment or something else, like flight control rigging?
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Don't know about Bonanza's, but the model airplanes I used to fly we would heat up the wing with a hair dryer and twist it.:goofy:

On a Cessna, there is an eccentric bolt holding the rear of the wing on that can be adjusted for angle of incidence. Ya gotta know what you're doing though.
 
There are so many planes out there that have become way out of rig over the years. I think they twist or maybe bend during hard landings/turbulence/heat cold cycles, who knows. (I saw a C172 a few years ago that had a rogue fixed aileron trim tab installed. It was bent up about 70degrees and everyone thought it had been backed into a post but nope that's just how it flew!) So you end up with a half dozen people over the years do the quick fix to raise a wing, center a ball.
The problem is, most airplanes require a good day's work to run through a proper rigging procedure. It means a lot of measuring, referring to specs, checking cable tensions, control surface angles, and then deciding on the problems and how to adjust, then reassemble and fly it, check for improvement, return, tear it apart again, readjust. No one wants to a) pay for this b)go through all this, so we end up with people doing the quick fix, a bend of this rudder trim tab, a droop of this flap, a tweak of this aileron.
The Cessna Pilots assn had a shop in Ca that was doing rigging on C's and were known for doing a thorough job but they are no more.
This is not a judgement of anyone, just an observation of how the world works!
 
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Dave Siciliano said:
They explained that of the four attachment bolts on the A-36, they could move the wing up to 3/8s of an inch. I would assume angle of attack, but didn't ask (unfortunatley, I was on the way somewhere and had to cut the call short). He said they would probably change aileron trim and maybe rudder. Guess we'll see.

Dave
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They are excentric bolts that change the angle of incidence. tiny adjustments there will give large corrections in lift on each wing.
 
When I bought my Mooney many moons ago, it needed rerigging. After the re-rig, what I had thought was an autopilot problem miraculously went away. (The autopilot would "level" the wings, at which time it would dive to the left, leading to an oscillation with ever-increasing amplitude.)

When I bought my Citabria from the factory, it was a little wing heavy and it benefitted from a rerigging, although that problem was minor. When I test flew the Pitts I just bought, it seemed to fly fine. But the prebuy mechanic (a Pitts guru) said the rigging was off and that a rig would make a world of difference in the handling. Haven't done that yet, though.
 
So you've dealt with a lot of rigging stuff Ken. It's pretty new to me. But it was apparent the A-36 wasn't flying as straight as it could. The P-Baron seems to be performing at book or better; so, probably won't spend a lot of time on rigging.
 
Dave Siciliano said:
So you've dealt with a lot of rigging stuff Ken. It's pretty new to me. But it was apparent the A-36 wasn't flying as straight as it could. The P-Baron seems to be performing at book or better; so, probably won't spend a lot of time on rigging.
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Not getting performance up to other models is a pretty good sign, too.

The problem with rigging is that you zero everything out according to the factory specs, and then fly it. You may still need to do some tweaking, at which point you can occasionally find yourself back where you started. It's a little like troubleshooting intermittent electrical problems in that it can be straightforward, or it can be an exercise in frustration.
 
I'm fighting a little rigging problem in my Mooney right now. To fly a straight heading the left wing is low and the ball is slightly to the left. Light left rudder brings up the wing and centers the ball.

The problem with the Mooney is that with a one piece spar there are no slots, or arcs or eccentrics to individually adjust the wings. Nor (on my vintage) is there any in cockpit rudder or aileron trim. Nor are there trim tabs on the rudder or ailerons.

As said before, getting the rigging right on our aging planes is time consuming.
 
Lance F said:
I'm fighting a little rigging problem in my Mooney right now. To fly a straight heading the left wing is low and the ball is slightly to the left. Light left rudder brings up the wing and centers the ball.

The problem with the Mooney is that with a one piece spar there are no slots, or arcs or eccentrics to individually adjust the wings. Nor (on my vintage) is there any in cockpit rudder or aileron trim. Nor are there trim tabs on the rudder or ailerons.

As said before, getting the rigging right on our aging planes is time consuming.
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If rudder can make it fly straight (wings level and calibrated ball centered) you don't need to adjust the wings, you need to trim the rudder.
 
lancefisher said:
If rudder can make it fly straight (wings level and calibrated ball centered) you don't need to adjust the wings, you need to trim the rudder.
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I need to have someone look at the rudder on my Grumman too. But I am not sure it's the trim, it may be something sticking.

Ever since I had it painted I have noticed that I need to hold left rudder to center the ball in cruise. But I discovered that if I kick in too much left rudder and put it into a skid, and then slowly let the ball return to center, as the ball centers I can feel the airplane sort of "settle" into a slightly different attitude. After that, I will no longer need to hold left rudder (until I make a turn) and my airspeed will be 6 - 8 mph higher.
 
GaryO said:
I need to have someone look at the rudder on my Grumman too. But I am not sure it's the trim, it may be something sticking.

Ever since I had it painted I have noticed that I need to hold left rudder to center the ball in cruise. But I discovered that if I kick in too much left rudder and put it into a skid, and then slowly let the ball return to center, as the ball centers I can feel the airplane sort of "settle" into a slightly different attitude. After that, I will no longer need to hold left rudder (until I make a turn) and my airspeed will be 6 - 8 mph higher.
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Gary, it sounds like you have something binding the cables, maybe at the pulley. I'm thinking something soft, like a balled up rag.
 
Here's the latest update. Spoke with Glen Biggs today:
He's made some adjustments. Adjusted the trailing edge; left wing was all the way up. Put it down. There is 3/8ths of an inch of travel. Will adjust right wing up a little. it was off quite a bit. He still feels there may be a problem he hasn't uncovered yet. He's searching for the problem; may take a couple more flights.

He's discovered the rudder has been rebuilt on this plane; it has a twist in from the top to the bottom. Trim tab is bent full left; opposite of almost every Bonanza. Doesn't know the reason is rudder has twist in it. May be able to take some rivets out and fix or may need new skin. Doesn’t think it's really affecting roll; just not as efficient as it could be. Looked at the window seals; the seals are fine, but the windows need some adjustment.

He usually gets a plane out of here quicker. This plane needs a little more than most. Still a little befuddled and is trying to see if there's another problem. After we discussed things a little, he wants to make sure the yaw dampener is off even when the auto pilot is swithed off. It could affect the test flights if it's engagine. He'll give me an update next week.

Dave
 
For several years I used to perform lots of rigging checks. Something I noticed was almost every aircraft I performed a 100-hour or annual inspection on was out of rig. I would reset the rigging to the aircraft manual requirements and have the owner/pilot perform a test flight and make a record entry returning the aircraft to service.

Rigging Cessna and Pipers are pretty much the same with the cable systems and only requires a few special tools, which I have. However to rig a Beech aircraft it requires more special rigging tools to set the rig. Many mechanics including myself did not own or purchase a set of rigging tools because of the cost. I would farm out the rigging to a shop I knew that had the proper tooling and training to rig Beech aircraft.

Something I learned from past experience if someone had performed any rigging I would check it and if necessary start the process over myself from scratch from start to finish. On some aircraft a mechanic would tweak the aft wing eccentric bolts (bad thing).

If I found an eccentric bolt had been moved I would jack the aircraft and snap chalk lines like the maintenance manual calls out to reset the angle of attack back to the correct position and begin re-rigging the entire aircraft including the trim tabs. Having an eccentric bolt out is the worse thing that can happen to an aircraft. Resetting the wings angle of attack takes time and a lot of patience and should not be accomplished by an untrained mechanic.

One last thing I learned over the years the aircraft may look like it has the right wings installed, but never assume. The same make and model aircraft may have two different wings installed with the wrong twist. No matter how good a rigger you are you can never get it to fly right. The wings have to be match sets by serial number learned this the hard way once on a Cessna. This is why good record keeping is important.

Just one man’s opinion.

Stache
 
Dave, all I can say is, Wow! I mean, you said it was off quite a bit and your A&P said this one will take a bit longer. As I was reading your update I was thinking of your flights to Merida, San Diego, WI, et al. Makes a guy wonder......

I am not at all surprised by Denny's comments. I see guys pushing on parts which shouldn't be pushed on. I've seen guys--including high time pilots and CFIs--bending tabs back to position by eye.
 
Lance F said:
I'm fighting a little rigging problem in my Mooney right now. To fly a straight heading the left wing is low and the ball is slightly to the left. Light left rudder brings up the wing and centers the ball.

The problem with the Mooney is that with a one piece spar there are no slots, or arcs or eccentrics to individually adjust the wings. Nor (on my vintage) is there any in cockpit rudder or aileron trim. Nor are there trim tabs on the rudder or ailerons.

As said before, getting the rigging right on our aging planes is time consuming.
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Lance, there are three travel boards (huge protractors) used to rig a Mooney. The entire process isn't all that involved, simply involves raising the aircraft off the ground, retracting the wheels, leveling on horizontal skin line on the aft fuselage side, and then checking with the travel boards. However, the boards are expensive (~$600/set for an M20J). The good news is that Wilmar will rent you the entire travel board set for $20.

FWIW, a Mooney will drop 3-5 kts cruise speed in a heartbeat if the rigging is off very much at all, and more if things are really out of kilter.

Also, FWIW, the wing on a Mooney is rarely, if ever, tweaked--it's usually the control surfaces.
 
Stache, Richard: Thanks for the comments.
This is why I've taken it to Glen Biggs; he's kind of the local Bonanza skin and rigging guru. He talked me out of a P-Baron that had had a hard landing. Even thought repaired by a factory shop and properly signed off, he saw indications of damage that couldn't be confirmed without opening up the wings where the repairs had been made. That plane didn't quite fly correctly either.
As far as the Bo; nothing dangerous about it now, it's just not as efficient as it could be. I also had the wing bolts pulled and inspected about a year ago and, as diligent as my A&P tries to be, this is very precise stuff. Who knows! The rudder trim has been left since I purchased the plane.

This is how ownership of a keeper is different than buying something to fly a few years and sell. If you're going to keep it, you can do fine little tuning things that a transient owner would never spend money on.

This planes had several owners prior to my purchase. Some took really good care of it; others, had no idea what they were doing. It's another reason to think low time, few owners or new if you're looking for a keeper of a plane.

Dave
 
Ed Guthrie said:
The entire process isn't all that involved, simply involves raising the aircraft off the ground, retracting the wheels, leveling on horizontal skin line on the aft fuselage side, and then checking with the travel boards.
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Ed, I'm curious about one thing. I know about leveling the pitch axis along the two screw heads on the aft left fuselage side. But what's the official way to level a Mooney in the roll axis?
 
Lance F said:
Ed, I'm curious about one thing. I know about leveling the pitch axis along the two screw heads on the aft left fuselage side. But what's the official way to level a Mooney in the roll axis?
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This may not be applicable to a Mooney, but many aircraft use the pilot/copilot seat rails as a level reference.
 
Glen Biggs has done a couple more tweeks on the A-36 but says he still feels there's something he can get better. Right flap was hung a little low; so, he's giong to fix that next, then test fly it again.

I'm sure a lucky guy. If I didn't have two planes, I'd have been grounded since early December :rolleyes:
 
Glen Biggs has done a couple more tweeks on the A-36 but says he still feels there's something he can get better. Right flap was hung a little low; so, he's giong to fix that next, then test fly it again.

I'm sure a lucky guy. If I didn't have two planes, I'd have been grounded since early December :rolleyes:
 
I am happy for you too, Dave.

Twice!
 
SCCutler said:
I am happy for you too, Dave.

Twice!
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Hey Spike, did you hear any more from Ben? Sent him a PM and never heard back. Last I knew, he was coming here today.

Dave
 
Looks like we're getting the rigging issues cleared up on the A-36. The latest is each of the flaps had a slight twist in them--about a quarter inch from the inside to outside. They were causing the plane to roll to the left. They looked twisted; so, Glen took them off the aircraft and put them in his jigs to check them; they didn't lay flat in the jig. He thought one could be fixed, but wasn't sure; so, we are replacing them both.

When that's done, he will pull the front seats out to have them recovered and touch up the paint on the aircraft. From there, it's back to GAMI to them to re-test fly the plane with the new prop. Then, just then, I may get it back to fly!!

Dave
 
wsuffa said:
All this, and you're selling it???
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Who said I was selling it :rolleyes:

Actually, took it off the market. When I did, I decided to fix it up as a keeper.
 
Dave Siciliano said:
Who said I was selling it :rolleyes:

Actually, took it off the market. When I did, I decided to fix it up as a keeper.
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Sweet! Must be nice when your cold backup is an A-36!!! :D
 
Bill Jennings said:
Sweet! Must be nice when your cold backup is an A-36!!! :D
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Actually Bill, I'm doing this to solve a big problem!

My estate was starting to get too complicated. After sitting in a bunch of boring meetings with these "advisors" changing outrageous rates per hour; then, having to read these boring documents setting up this trust to do this and this entity to do that--it came to me. No substantial assets means no more big estate issues; no estate issues, no more boring meeting with paperwork to follow!! Now, I'm on a roll--get rid of all those pesky assets. I'm free----I'm free. Or, at least for awhile :blueplane:

Dave
 
Dave Siciliano said:
Actually Bill, I'm doing this to solve a big problem!

My estate was starting to get too complicated. After sitting in a bunch of boring meetings with these "advisors" changing outrageous rates per hour; then, having to read these boring documents setting up this trust to do this and this entity to do that--it came to me. No substantial assets means no more big estate issues; no estate issues, no more boring meeting with paperwork to follow!! Now, I'm on a roll--get rid of all those pesky assets. I'm free----I'm free. Or, at least for awhile :blueplane:

Dave
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LOL I'd do the same thing in your shoes.

But, if you want to feel even more free you could purchase me a nice V35 Bonanza...you know just to help you out a bit.

Info (always coming through to help in a jam) tango
 
Dave Siciliano said:
I'm free----I'm free. Or, at least for awhile :blueplane:
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LOL! I think my parents, in their retirement, are doing the same thing on a smaller scale. Hey, they earned it, they deserve to enjoy it, as do you. Enjoy, Dave!
 
Dave Siciliano said:
Who said I was selling it :rolleyes:

Actually, took it off the market. When I did, I decided to fix it up as a keeper.
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How close is it to TBO? With the TATurbo on there, how hard is the overhaul?
 
Chris:
We're past the ten year age limit: the IO-550B was put in in 1994 but at around 1550 hours on a 1700 TBO. I've topped the plane since I purchased it five years ago. No problems with the oil analysis or filter check; it's running great. May very well stretch it a little.

I'll have to see what the overhaul will cost. There are three engine shops I've discussed with the guys I think highly of. The prop is pretty low time; the engine would be a complete rebuild; some of the turbo parts--like the intercooler could be resued. I'll just have to get a quote and it may depend on how my business is doing. Where I go to a specialty shop or factory for instance.

Dave
 
Glen Biggs called today to tell me the things we discussed have been completed. Parts are on the plane, everything painted that was replaced and the touched up a couple other areas. He flew the plane today and is happy with everything but the rudder. It has been rebuilt, the trim tab goes the opposite direction of 90% of bonanzas and it's twice as big as most trim tabs. So, Glen is going to replace the rudder with an existing one. If it doesn't improved things, he'll put the old one on and we're done. If it improves things, he'll take it off and reskin the existing rudder. Should be able to get to this next week.

He said on the test flight the the plane flew well, ball centered when properly trimmed, flew straight, etc. It's going to be nice to get this back and see/feel the difference in handling and speed!!

We're also looking at recovering the seats and arm rests.

Dave
 
Great news! I'm pretty lucky that 37S flies straight and level with the ball centered.
 
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