Rigging

[robert7467]

How much does rigging normally cost, and can any A&P do it? I disabled wing leveler with rubber band on yoke to see how she flys, and she wants to pull right and downward. With wing leveler, she flys strait and cordinated.

[Bennett]

If you are in the West, I suggest calling LASAR, and talking to Mike or Paul.  They recently ran a "special", which might still be in effect, that if you had other work done there, they would do a free rigging.  They re-rigged my Mooney last month, and I am very happy with the results. I can take my hands off the yoke, leave my feet on the floor, and the airplane will just track along perfectly, with no tendency to drop a wing, or turn.  Better yet, I picked up a knot or two.  Previously, while the airplane otherwise tracked fine, both ailerons were up about 2 to 3 degrees in level flight.  I'm sure that I have read that the Mooney factory extensively tested various positions of the ailerons, and upwards deflections resulted in a moderate loss in airspeed.  In my case, various bushings were worn, and therefore replaced, along with taking a bit of "slop" out of the controls. 

[robert7467]

So if they were willing to do it for free with other services, then it shouldn't be that much I guess..... I am in the Memphis area

[rob]

She wants to pull "right and downward"? Does that mean that you lose altitude due to the loss of lift created by the right banking, or does the plane fly downward? 

[1964-M20E]

On my previous plane I worked with the mechanic and did the rigging after changing some rod ends.  We rented the travel boards and followed the manual.  It most likely took us longer than an MSC but it was a great learning experinece and the plane flew good before and after.

[robert7467]

I guess the best way to describe it is "drop a wing" in the above post from Bennett.

[KSMooniac]

It isn't a fixed-price job because it depends on how bad it is, what needs adjustment, and what needs replacement.  Hard to quote without flying the plane, and even then you don't know definitively until you dig into the job.

[Marauder]

It isn't a fixed-price job because it depends on how bad it is, what needs adjustment, and what needs replacement. Hard to quote without flying the plane, and even then you don't know definitively until you dig into the job.

I second his comments.the underlying problem that caused the issue needs to be found. It can be something as simple as an airelon with slop in it or a bent flap from extending them at too high of an airspeed. Mine was a mis-rigged landing gear.

[robert7467]

Interesting. It's got to be something in airleons since the wing leveler fixes it.

[rob]

The wing leveler being able to fix it doesn't necessarily mean its in the ailerons, it just means that it's correctible with aileron input. It could be any number of things causing it. Including one that's simple to check: was the fuel equal or nearly so, in each wing?

[jetdriven]

The service manual calls for rigging the flaps as well for roll. A 1/2 turn on that flap up stop screw makes a large difference in roll.

[N201MKTurbo]

You can rig the airplane in a few hours. If you want to maximize the speed of your airplane it takes weeks. I am an A&P so I can do it myself and have done my last two planes.

My current J refuses to go any faster and it should, I suspect it is because of the wing repair after the past owner hit a tree.

 

But My old F model, that shows what can be done with rigging, I actually got it to perform to book values, which everyone thinks are wildly optimistic.

I found the biggest gain was with aileron angle. I would adjust the angle through the allowed range ½ turn of one rod end at a time and then test fly the plane. I did the same with the flaps. When I got close I started moving the ailerons and flaps in unison until I found the sweet spot that gave me the most speed. This gained me 7 knots without spending a penny on speed mods.

 

There is also some speed to be gained by optimizing the elevator bungee tension in the tail. You can find the sweet spot by going out on a calm day getting the plane stable and noting the airspeed. Then move the trim to where you have to hold pressure on the yoke to fly level and note the speed, it will change ( a little) find the mis trimmed position that gives you the highest speed then re-adjust the spring bungees to bring the highest speed and the trim position together. This will alter the trail angle of the elevator at cruise trim.

 

It is also very important to make sure the landing gear are closing properly. If they are hanging to low or the doors are not laying flush with the wing, it will slow you down.

 

I found that if the belly skins are wrinkled by not tightening the screws in the correct order it will cost you as much as 3 knots.

[N201MKTurbo]

There really cannot be slop in the ailerons. The lift produced by the ailerons causes the rods from the two sides to pull against each other which removes all slop except on the linkage between the yoke and the center bell crank.

 

Have you ever noticed how much slop there is in the ailerons while on the ground, but while flying it is absolutely precise? This is because of the aerodynamic tension put on the control system.

 

The trim system is doing the same thing. The horizontal stabilizer has down force on it that takes all the slop out of the trim system.

[nels]

There really cannot be slop in the ailerons. The lift produced by the ailerons causes the rods from the two sides to pull against each other which removes all slop except on the linkage between the yoke and the center bell crank.   Have you ever noticed how much slop there is in the ailerons while on the ground, but while flying it is absolutely precise? This is because of the aerodynamic tension put on the control system.   The trim system is doing the same thing. The horizontal stabilizer has down force on it that takes all the slop out of the trim system.

Great comments. All make sense.

[robert7467]

Went out to the plane, and the left alerion was pointing down a little, and the right was level with the wing. With the left alerion down it is causing lift on the left side, which is causing the plane to bank right. Is there any easy way to adjust the alerion? The maintenance manual is not specific. Thanks

[jetdriven]

Robert, it doesnt work that way.  Aerodynamic loading centers the ailerons in flights.  The service manual calls to lock the control wheels in the centered position (yuo can tape a long straight bar to the bottoms of the yokes to lock them together and centered).  Then you adjust the ailerons and flaps per the service manual.  I wouldnt touch it without following the manual to the letter. There is a specific sequence of steps to rigging an airplane.

[robert7467]

Yeah, I didn't see an adjust point on the pushrod going into the alerion, and the manual is not specific, so I am going to have my mechanic look at it. It now makes perfect sense of why it's doing what it's doing. Even though the wing leveler corrects it, I want everything to be right.

[robert7467]

Let me rephrase that. The manual is specific on the tolerances, but not exactly where the adjustment points are.

[jetdriven]

The aileron adjust threads are on the rod end that goes to the bellcrank inside the wing. You pull the aileron horn bolt and rotate the whole pushrod to adjust the length.

[robert7467]

Ok, so the rod that bolts on to the alerion... Take out the bolt, and turn it? As far off as this is, it would make a huge difference, just to line up by sight, but I would have my instructor with me who is a A&P.... I have a great, clean well maintained plane, but it's a never ending squak list... That's half the fun, keeping these old birds maintained. I spent last summer polishing and waxing her. My wife says I am married to my plane.

[jetdriven]

I would caution you to strictly follow the service manual on rigging. Everything with the flaps and ailerons affect each other. To adjust the aileron, you pull the inspection cover at the bellcrank end of the aileron pushrod, loosen the jamnut on the rod-end.  Then you remove the bolt that holds the other end to the aileron.  Then you turn the whole pushrod in 1 turn increments (it has a bend in it) to get the aileron where you want it.

[robert7467]

Gotcha. I see that there are special rigging tools. I am going to see if my mechanic has them, and I guess let him deal with it.

[georgeb]

Before you go and down the re-rigging road, I would suggest making sure the outer 2-3 inches of the ailerons are not bent even the slightest bit. That is the way that minute adjustments are made specifically for these situations. I did the whole ringing thing and In the end, the last bit of heaviness that the plane was experiencing was due to the afore mentioned. At some point, without anyone noticing, the trailing tip of one of my ailerons was bent up, and I mean like less than 1/4 inch on the last inch of one the ailerons. That was enough to have the Wing drop every time I disabled the wing leveler. You couldn't even tell unless you looked closely at the aileron.

Just food for thought and something else to look for.

Good luck