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Airframe: Ailerons – Monty the Answer Man Archives

A RIVETING TALE… (well, aileron, actually)…
From: Eddie Shields (WVSWIFT@aol.com)
Re: Swift aileron
Jim, I need to know how to line up my aileron prior to start riveting it back together. Is it a straight aileron or does it have a twist? If so, how much? I didnt realize how much it would move around without skins on both sides. Eddie Shields 2403B

Eddie, As far as I know it straight. It should line up correctly when you cleco the skins in place. You did back drill them using the old skins, right?  —  Jim

Jim, I did back drill all the skins from the old skins but didn’t do the trailing edge. I wanted to do that to have a nice straight row of rivets and use my air rivit squeezer to avoid bowing. I have already bucked the top skin on by using the old bottom skin in place. Thanks, Eddie

AILERON & FLAP BEARINGS…  (12599)
Subject: Re: bearings
From: skipnann@earthlink.net
In need of a source for the bearings that press into the flap and aileron wing fittings.

Skip
Those are K3L and K3SL bearings. The “S” denotes “swivel”, the tail surfaces have plain K3L and the flaps and ailerons have K3SL. I would imagine Joe at Swift parts has them. I see Aircraft Spruce has them also in their catalog.   — Jim

CONICAL WASHER PART NUMBER… (060100)
Subject: Re: Need part number
From: Eddie Shields <WVSWIFT@aol.com>
Jim,
Do you know the part number to the conical washers that go around the flap bearings at the attach point?? Is that the same ones that go at the aileron attach point also?? Thanks, Eddie Shields

Eddie,
Those washers go everyplace a KS-3L bearing is used. (At the flaps and ailerons on a Swift) I don’t know of a p/n but Swift Parts has them. The DC-3 used them and we used to have them in stock at the airline, but Swift Parts is the only source I know of these days. Missed you at the fly-in. — Jim

YOU MUST BE YOKING…  (070100)
Subj: NC80505
From: Joe Murphy
Jim,  I am having some trouble with my yoke column. It does not move very freely, but is rather stiff. Lewis Brashear, a local Swift enthusiast, has taken the covers off the column and gotten underneath the panel. He says that the nylon bushings are new, and he has put some grease on the column and that has helped some. Can you give me any advice. Thanks, Joe Murphy

Joe,
Usually, some silicone grease applied to the control columns or the bushings will free things right up. The “nylon bushings” statement puts up a warning flag to me. Originally, the bushings were made out of a micarta type phenolic material. No doubt someone has put some more modern material in there. Perhaps they are fitted too tightly. As you know, N80505 was out of service for about 30 years until it got restored in the ’80’s. Check AD 47-06-03 to make sure it has been done. Perhaps that AD note “slipped thru the cracks”. It is S/.B #8. — Jim

HOW TO SET-UP THE AILERONS… (110400)
Subj: Rigging
From: Brian Silcox <76250.2445@compuserve.com>
Dear Jim, I’m interested in checking the rigging on the ailerons on N46GS. I think the adjustment of the rod ends is a little off, as one aileron appears to be up, and the other “faired” with respect to the adjacent flap, when stable hands off cruise trim. I am guessing the flaps and ailerons have a specified inclination relative to level??? Thanks, Brian Silcox

Brian,
The Swift Operators Handbook gives a good procedure on aileron rigging. Refer to pages 28 and 29. Note the ailerons should be adjusted “neutral” in other words, “0”. This is accomplished by adjusting the push-pull rods from the actuating bellcrank to the aileron so that the center line of the aft arm of the bellcrank is at a 90 degree angle to the spar when the aileron is in neutral. Wing heaviness should first be corrected by raising or drooping the flaps. Minor wing heaviness can be corrected with the tab on the left aileron. In my experience, the smaller engined, more underpowered airplanes benefit from drooping both the flaps and ailerons slightly. The big engine airplanes may be faster with the flaps and ailerons slightly reflexed, i.e. adjusted so the neutral position is above wing chord plane. You may not like the stability of the airplane when so adjusted. If you like aerobatics remember, the “down” aileron is the one that gives good roll authority. (It goes down into a high pressure area, the up aileron goes up into a low pressure area) Many Swifts have the stops set to limit aileron travel. I see no good reason for this. I believe in setting to the max allowed figure of 16 degrees down and 19.5 up (+2)

To get the ailerons right to start with, tape a yard stick across the control wheels to keep them neutral. If you have sticks, use a “T” square and tape with masking tape or duct tape after you find neutral. You can eyeball the bellcrank or make or buy a swinging protractor to find the aileron angle. You may want to disconnect one or both aileron cables to get the push-pull rods adjusted, then reconnect when you can easily do so, then tension the cables to 20 lbs. – a little less tension may make the ailerons feel better. — Jim

MORE ON THE RIGGING ISSUE… (110400)
Subj: RE rigging
From: Brian Silcox <76250.2445@compuserve.com
Jim, I found the section in my owners handbook on rigging…. my question is, what is the 19.5 up, neutral, and 16 degrees down measured relative to? Is it the top skin of the wing, or reference level with the airplane leveled? Thanks, Brian

Brian,
Neutral is more or less determined by eyeball. Some strips of wood can be duct taped* to the top skin and the bottom skin and the aileron should be faired. Or you can align it with the wing tip. Or if the flap is in line with the rib at the wing walk all these items can be used to determine neutral. If you were going to work on one Swift after another a rigging board could be made up – they probably had one at the Globe factory. A swinging protractor can be bought from aircraft tool suppliers or one can be made with a school protractor, an aluminum angle and a suction cup. (Or simply duct tape* the angle to the top aileron skin.) With neutral found, the up travel and down travel angles can easily be determined. If neutral, measured at the top skin is an actual 25 degrees, set the protractor to “0” after you have determined it is neutral, then up is 19.5 degrees from that and down is 16 degrees from that. (I use the plus 2 degrees for maximum aileron travel) * Red Green, are you listening? — Jim

ALIERON BELLCRANK BOLTS… (070201)
From: John Cross <jpcross@airmail.net>
Subject: Aileron Bellcranks
I pulled the bolts on the aileron bellcranks today. They were stripped, so I had to do it. Anyway, I got some new AN3 bolts to replace the old ones, and guess what, they won’t go through the bushings! Any tips, secrets, advice, etc? I am stumped. BTW – I am almost done with mounting an overhauled O-360 on N2398B. The belcrank issue came up during the annual part of this exercise. — John Cross N2398B

John
The bolts at the cable attach to the aileron belcranks are a special truss headed AN3 screw type. I forget the AN number, but if regular AN3 hex head bolt is used it will hit the cable on the aft end. Regardless, the diameter of all AN3 bolts and 10/32 should be .190 as manufactured. If the bushings in the bellcrank are smaller than .190, say .187, a bolt can be polished down to fit. If the bushings have been buggered by some incompetent mechanicing, ream them to .190.

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