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Elevator Trim/Electric Trim – Monty the ANswer Man Archives

ELEVATOR TRIM LOCATIONS… (5599)
Subject: Re: trim
From: Keith Bracht <kab_bjb@skat.net>
Jim-
Thanks for the trim info. As much as I’d like to keep the original setup, I find myself under trimming just because it is so awkward for me to get to. My wife doesn’t enjoy getting an elbow in the side of her head either. Looking at the area between the fuel gauge and the bench seat back there doesn’t seem to be much room. Does this mod require a split seat back or a gap between the bottom cushions? My bottom cushions don’t have have much of a space between them. BTW, I had 29K out of the hanger yesterday in the sun. It is unfortunate that the scans didn’t capture the true colors and brightness of the paint. It is dazzling. Bill Shepard checked me out and made some very nice comments about the airplane.

Keith,
The late “deluxe” Swifts had the trim wheel located by the gas gauge. The trim cables are rerouted beneath the baggage compartment and go to a drum which is tuned via a small bicycle chain from the trim wheel. You could ask Joe in Swift Parts if they have the drawing to sell. Univair sold a whole kit for this installation when they owned the t/c. The 172 setup is nearly identical and maybe you could adapt it via a field approved 337. If you did it per the factory drawing it actually is “original equipment”. You might find a late airplane with this trim system installed and look at it. Our N2460B is a “standard” (cheap) Swift and has the early type setup. I remember N2440B was the “deluxe” model and had the trim wheel by the gas gauge.  N2432B is in WA state, but I don’t know which style trim it has.  —  Jim

BETWEEN THE SEATS TRIM… (9399)
From: Tj3368k@aol.com
Subject: Between-the-seats trim
Are there any internet Swifters out there that have a 337 that approves a “between-the-seats” trim mod for the GC-1B? If so I sure would like to hear from someone. I’ve been getting nowhere fast. Thanks. T.J.Johnson,Tj3368k@aol.com, Okla City

TJ,
The “Deluxe” late Temcos had the trim relocated, the first airplane that had that done was N2307B, s/n 3607, apparently the owner worked for Temco and the work was done on the basis of a 1948 field approval and the other airplanes that had the same system were done with reference to that 337. That airplane was owned until recently by Ed Krause of NY. He may have sold it recently. Ed’s email is n97697@cecomet.net. Attached is the copy I have of it. The trim is actually not between the seats, but below your knees on the front spar web. I just re-read the 337 for the first time in a long time. It is dated 5-1-50 and has reference to drawing 5171 – I wonder if they have that at Swift Parts? Jim

ELECTRIC TRIM… (010300)
Subject: Re: Elecric Trim
To: kab_bjb@skat.net
You mentioned to Steve Wetherbee you had copies of a one time field approval. Could you tell me a little more about it? Is a manual backup or reversion required to keep the Feds happy? Thanks. — Keith

Keith:
I’ll look for it. I haven’t looked at it in years, but it seems to me it was just a reversible 12V geared motor mounted above the trim crank. The one Nagle used with the canopy had no backup. Apparently, he convinced the feds that you could overpower full trim in either direction and still land the airplane. — Jim

ELECTRIC TRIM #1…  (060500)
Subj: Electric trim
From: Jay Prentice <JWPREN@aol.com >
Would you recommend different ways to add electric trim? I like the idea of a manual backup, but I am open to all ideas. Jay Prentice <JwPren@aol.com>

Jay,
There are several field approvals for electric trim. The canopy installation uses electric trim with no backup. Apparently, Jack Nagle proved to the feds the airplane is controllable and landable with the elevator trim in either extreme. I don’t know how the feds would grant an approval for an electric trim just using THAT for a basis. I have not seen the canopy STC, but I understand the wording is a little light on some details such as that. Could someone copy their STC paperwork

and let me take a look at it? I have a copy of a field approval which used a surplus reversible 12V motor mounted on top of the trim crank and retained the crank for backup. — Jim

ELECTRIC TRIM #2…  (060500)
Subject: Re: Elect Trim
From: Jay Prentice <JWPREN@aol.com >
Jim, I just received your email and would like to know more about the 12v motor to run the trim. Right now I have a 28v cowl flap motor (which runs real slow) and a double pole double throw switch. I broke the switch and I am replacing it with a MAC SPDT four way switch and relay deck. I would like to install a 12v motor with manual hand crank and maybe a speed relay. Thanks Jay Prentice <JwPren@aol.com>

Jay,
I will look for that 337, but as I recall, it gives little detail as to the type of motor. The airplane it was installed on was N3209K, which I believe is based at Zeuhl, TX, near San Antonio, maybe you could get down there and look at it! Hmm…maybe that wouldn’t do any good. N3209K now has a canopy, and that installation is probably now history. Maybe you could buy that setup from the former owner, Dorothy Golding! — Jim

THIS IS NOT AN EASY JOB…  (060600)
Subj: Elevator Trim
From: Steve Stevens <SSN80564@aol.com>
Jim,  The elevator trim rod that the spool is on broke loose from the mount and bearing that is connected to the spare or the bulkhead in the horizontal stab. Can I get just a new mounting unit, or how do I fix it? It is hard to explain without talking to you. The cable is still on the spool and the rod seems OK. It has just come disconnected from the forward mounting bracket. It looks like there is a bearing with a key which slips into the rod. The key appears to have broken off at the bearing. Need some advice on how to fix it and what I have to get for parts. Thanks, Steve Stevens

Steve,
They probably have the part you need at Swift Parts. (probably!) There is a screw that goes into a drum that from your description I would guess is broken. If I haven’t followed you and it is the drum that you need they might have that too, but if they don’t, run an ad in the various publications. These items almost always survive a crash, so there must be used ones around. If the ears broke loose from the spar, the aluminum is probably weldable, although I haven’t ever had to do that. It is a real pain in the rear to undo the trim cables. If they have never been worked on before, you need to go in the aft fuselage and remove the tension spring and cut the safety cable that connects the two trim cables. Before you do that, you may want to put in a long spring or a bungee to maintain tension on the trim cables. Otherwise, the cables will “birdsnest” when tension is relieved. If you don’t know what that means, just try it and you’ll see! After the cables are off the drum you can remove the assembly and determine what you need to do to make repairs. I am installing new trim cables right now on N80796, so I empathize with you! — Jim

WELL, OK, MAYBE IT WON’T BE THAT HARD AFTER ALL…  (060600)
Subj: Re: Elevator Trim
From: Steve Stevens <SSN80564@aol.com>
Thanks for the information. The drum is all right and the cable is still on it. The rod came off the plate that bolts to the rib or the spar in the horizontal stab. It looks like a bearing or something broke allowing the rod to drop free. I do not think it is going to be an easy fix from the looks of it. — Steve Stevens

Steve,
You may be in for a little luck. There is a K3L bearing at the forward end. It sounds like that bearing has disintegrated. It only lasted 54 years. I don’t suppose it ever got lubricated. You need to tape the trim cables down with duct tape, or make a cable block up with a couple of pieces of wood and a screw to keep the cables from birdsnesting off the cable drum. Then you can remove the two AN3 screws in the steel bracket with the ears on it in the rear spar. You can then remove the two AN3 screws holding front bracket on the false spar at the forward end of the trim mechanism. The drum assy. has a AN3 (10/32) stud extending thru the K3L bearing. After you get it free, you can remove the cotter key and castle nut and remove the front bracket (bearing block) and replace the bearing. They have those bearings at Athens. Let me know if it is, in fact the bearing — 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

ONLY TEN CENTS WORTH… (070600)
Subj: Elevator trim indicator cable
From: Mark Runge <rungem@ameritech.net>
Monty, Can you tell me where I could get a piece of the small cable that goes from the elevator trim mechanism up to the trim indicator? Thanks, Mark

Mark,
You can use regular .020 stainless steel safety wire, just plain fish line, or if you want a multi-strand cable use the stuff model airplane guys use for control line models. I just have plain .020 safety wire in mine. It takes about 10 cents worth to run from the tail to the cockpit. — Jim

A CABLE RUNS THROUGH IT… (080100)
Subj: Re: control surface balancing
From: Michelle Dolin <swiftgal@hotmail.com>
Hi Jim, We are in the process of rebuilding the horizontal. We have to replace the forward channel piece, that ties the 2 forward spars together, and the trim cables run through it. Is there a trick to getting the trim cables off? We can only see one attach point for the cables, and it has the spring and the safety cable attached to it. It sure would be great, if we could get the cables off, without having to unwind the assembly… Thanks — Michelle

Michelle,
At the cable drum in the left horizontal it is necessary to tightly wrap the cables with duct tape or make cable blocks with two pieces of wood and a screw to hold the cables on the drum and prevent them from “birdnesting.” Then you must go in the aft fuselage and remove the tension spring and cut the safety loop. Then pull the cables free, after removing the stop blocks, pulling the one around the trim crank pulley. You may want to remove the whole trim mechanism from the aircraft next. Somewhere along here you will remove the stabilizer from the aircraft. I presume you can figure out the sheet metal procedures to replace the center spars. — Jim

EXCESSIVE PLAY IN TRIM TAB…(110500)
Subject: Re: Trim Tab
From: Bob Runge <ejectr@javanet.com>
While doing the lubrication on N80528, I notice I have excessive play in my trim tab. Although some of it is from the connecting arm bolt hole, the majority of it seems to be coming from the end that is inside the horizontal stabilizer. They must have put that in and built the rest of the aircraft around it for there is this slight hole right where that arm connects to the drum mechanism and I can barely see in there. What’s connecting that end to the drum, Jim? Is it another bolt through a bearing? Swift maintenance manuals don’t give much info on the trim mechanism. Thanks. Best regards……. Bob Runge

Bob, There is a threaded “slug” at the forward end of the actuating rod. To remove it is simple. Just remove the 3/16″ bolt or screw at the tab arm, then unscrew the rod and threaded “slug”. You may want to count the turns to be able to reassemble it the same way it came apart. You can inspect the parts for wear. If you find wear, Swift Parts may have the parts available. A coating of heavy grease may help your condition. When reassembling, make sure the trim tab travel is what’s called out in the operators manual. Hint – when trimmed full airplane nose up the power off glide should be the target airspeed for landing approach. i.e. about 80 mph. — Jim

SETTING UP THE ELEVATOR TRIM CABLE…(120301)
Subject: Re: Elevator trim:
From: Bill Doty <wdoty@earthlink.net>
Jim, As usual a question.. 80572 was disassembled when purchased … The elevator trimmer was not hooked up.. Can you define the spring, in the cable or give me an indication of the tension on cable?? My trimmer is located in the top of roll-over bar and looks original. It has a phenolic pulley which would indicate only one pass around the pulley. Is this correct??

Bill
The trim cable is just a simple loop, going around that pulley at the fwd end and has several turns around the drum in the left horizontal. The tension on the cable is maintained by the spring. I would guess the tension is not over a couple of pounds. To set it up, the cable should have its turns around the drum, then a cable block should be installed temporarily at the IB rib of the horizontal to prevent the cables from bird nesting. (fabricate a cable block with two pieces of wood, 1/2″ x 1/2″ x 3″ and a 3/16″ bolt) Then route the cables. There will be a gap of something less than a foot between the thimbles at the ends. This is where you install the spring. A safety loop can be installed beside the spring. The trim travel stops are phenolic clamps adjusted to contact the bulkheads to limit travel. — Jim

MORE ON SETTING UP THE ELEVATOR TRIM CABLE…(010402)
Subj: Elevator control
From: Joe Sills <JGSILLS@prodigy.net>
Hi . I am restoring Swift 80737 s/n 140 , I got this project in boxes and have rarely had another to look at . Ed Lloyd has flown his up for me to look at and take pictures of in the past but I hope you can answer this without me having go down to Zheul and look. I am having trouble figuring the number of wraps the cable goes around the spool for the elevator trim . I haven’t found any info in the archives on this. Thanks : Joe Sills

Joe
I don’t remember exactly the number of wraps on the drum. Just wind one cable up as far as it will go, then get the slug from the other cable in its slot, then pull the first cable to get about the same amount of turns for both cables on the drum. Apply a cable block to prevent the cables from birds nesting off the drum. (make the cable block from 2 pieces of wood about 1/2″ x 3″), and drill in the middle for a 3/16″ long threaded bolt or screw) Route the cables. Crawl in the aft fuselage. There should be a gap between the cable ends so the spring has the right tension. If it too much of a gap, either unwind one turn or more as required, or get a longer spring! — Jim

NEEDS PAPERWORK FOR ELECTRIC TRIM…(070302)
Subj: SWIFT TRIM ….337 NEEDED
From: mlimri@yahoo.com (monica inskeep)
I have just set up a electric trim unit in my Swift. I used a pitman gear motor. I mounted it just behind the stock location using 2″ angle. I made an aluminum pulley with an extended shaft to remount the crank handle back on. I made the angle long enough to place 2 relays on for the reversing circuit. It works great. Now for the reason I am writing you. I was looking at the old archives and saw that this has been done before and perhaps there is already a 337 on it. Buzz Winslow asked me to see if we could get a copy of it. I planned to have a field approval and this would help greatly. As I’m sure you realize. Thank You. Michael. E-mail me at: mlimri@yahoo.com.

Michael
Erin Chanson has a limited approval on an electrc trim system, but it is considerably different than what you describe. I don’t know if anyone has an approval for one like yours, but maybe someone will reply. — Jim

MARK KADRICH COMMENTS ON THE CESSNA TRIM MOD… (FEB 03)
From: Mark Kadrich <starwizz@pacbell.net>
Subject: RE: January #4 GTS Internet Update
Jim,
I have the Cessna trim in 43K and although it has a distinct advantage over the stock trim, (you don’t wind up with arm cramps) there are some interesting problems. In the Cessna system, the indicator will tell you where the trim wheel is set, not where the trim tab is set! The reason is that the trim indicator is a needle that rides in a spiral grove machined into the trim wheel itself. As you turn the wheel the needle move in a similar fashion to a needle in a record. As the needle moves, it pushes an arm (not unlike a tone arm) along an arc. The end of the arm has the indicator on it and you read it through the slot. The reason that this is a problem in the Swift is that the travel for the trim jackscrew is greater then the amount of travel allotted by the spiral. The way the grove is machined, at least in my airplane, is the end of the spiral at the center is machined such that the needle can jump if you keep turning the wheel. So when you command nose up trim, the end result is the trim jackscrew keeps moving but the trim indicator does not. When you’re done it still indicates full up nose. The good thing is that you do have full up nose trim. When you turn the wheel the other way, The needle moves through the grove but the end of the grove at the outside is flat and won’t let the needle jump. The end result of this is that you wind up with less nose down trim. On my ship after a few times I could only get the trim tab back to even with the elevator! Very evil depending on how you’re loaded. To fix the problem what I did was use a hybrid of the old and the new systems. I used the wheel to set the trim, but I went back to the stock string indicator. The position indicator in the cockpit is connected to an arm via a very very thin cable that presses against the cable at the jack screw. As the cable moves along the jack screw if pushes on the arm pulling on the cable and moving the needle in the cockpit. It very accurately tells me where my trim tab is set. You just need to be very careful with the spring tensions or you can wind up with a very screwed (pun intended) up trim system since you can push the cable off of the jack screw. I can assure you that it’s no fun fixing that mess! If you are interested, I can send some drawings. As for the field approval….I consider this a non-structural modification. Don’t ask, don’t tell I suppose. My AI (unofficially) thought it was quite elegant. — Mark

MORE ON THE “CESSNA TRIM”… (FEB 03)
From: Steve Roth <Swift97B@aol.com>
Subject: Re: February #1 GTS Internet Update
Denis: I also have the Cessna Trim System in my ship and have none of the issues that Mark has. I really like mine. It operates exactly the same as in my old (1950’s) Cessna. As you probably agree, little trim change is necessary with the Swift but I have the full range of travel (if necessary). The neutral position mark is similar to that of an old Cessna. The only bad thing is that it is more of a challenge to crawl into the tail code with the trim wires in the way and there is the “tunnel” behind the trim mechanism (for the wires) which takes up a portion of the baggage area. All of my parts are Cessna, including the wheel with the grooves. Installed under Field Approval. Regards, Steve

TRIM RELOCATION… (AUG 03)
Subject: Re: trim stc
From: diamondswift@earthlink.net
The old STC, SA4-157, to relocate the trim to the left side of the fuselage is show as being held by M.E. Bodell in California. He was also the one that held the STC for the electric boost pump and Bonanza wing tips. Do you know who holds the STC now? As I recall, he donated the boost pump STC to the association. Did he do the same with the trim? Or, have I just lost my mind completely?

Don
I don’t know who, if anyone controls the Bodell STC’s now. The boost pump STC was held by Paul Lacy and he donated it to the Swift Assn. Bodell did have several STC’s. I don’t know if he is still around or not. As I recall, I tried searching M.E. Bodell and Mickey Bodell in <www.switchboard.com> a while back and didn’t find him. — Jim

MONTY ON THE ELEVATOR TRIM DEAL… (AUG 03)
Seeing the question about the trim in the newsletter jogged my memory. Did you know they made some Swifts with the elevator trim crank relocated to a point by your right knee? There was a kit available from Univair for all the parts necessary. The factory did this on a field approval! The Swift was owned by a Temco employee and the factory produced some other airplanes based on his 337. A 337 dated before some date in 1955 is accepted as approved data by the FAA. I believe the Swift with the trim relocated was N2307B. I might have a copy of the 337 here someplace. You might contact the present owner of N2307B also. I believe that whole setup was pretty similar to a Luscombe elevator trim crank, but I haven’t had a chance to compare them side by side. I used to be hangared with N2440B and that airplane had the trim relocated by the factory. — Jim

TRIM… (SEPT 03)
Subj: 2440B Elevator Trim
From: Robert Tomecek <swift40bravo@aol.com>
Dear Jim,
The factory TEMCO trim was removed from 40B when the sliding canopy was done at Dorothy Goldings place. I still have the parts and will eventually re-install them elsewhere since the Thomason sticks were in the way. Anyone out there every install it in a different spot like between the seats? Thanks, Robert Tomecek

Robert
Vince Fette installed numerous Cessna 150 or 172 trim wheels near the fuel gauge. I don’t believe there was any STC to cover this. I don’t know if anyone has a field approved 337 either. If someone has a 337 on this mod maybe they will let us know. Is there any paperwork for the relocated trim with your aircraft? If so, you might try for a revision to the factory installed related trim to a 172 type trim wheel. — Jim

LATE STYLE TRIM WHEEL MOD LOTS OF WORK… (SEPT 03)
From: Paul Lacy <Swiftwagon@aol.com>
Subject: Temco Trim
I have the “late” style trim wheel. I had it installed in 3296K by Piedmont Avn. Roanoke Va. in about 1975. They and I badly underestimated the work involved and said they’d not like to do them on a regular basis. I got the kit from Univair and it was totally complete. However, It necessitated relocation of the emergency fuel pump to the passengers side as there was an interference with the fuel lines. The end result was convenient and desirable, and the trim wheel is sort of like an early Bonanza with an internal ring gear located inside the wheel that drives a small pinion operating a position indicator visible through a small opening beside the trim wheel. I remember a Swift that had the stock trim relocated to the front of the windshield turnover structure (The area occupied by the stock hatch hold open), that used to come to KY Dam. I believe it had a stock hatch or a split hatch with a small channel used to protect the cables. I remember how much simpler it must have been to accomplish (longer cables, probably spliced behind the hat shelf bulkhead). Don’t know the history of it, or anything about paperwork, but at the time I wished I’d done something like that and saved my money and aggravation. Also there was a Swift with a Piper electric trim motor and no manual trim. I doubt you’d get by with something like that these days but the guy was tickled with it. I believe the theory was that you could fly a light control pressure plane such as the Swift in and emergency with the trim inoperable. I’d not like to experiment at extreme settings.– Paul Lacy

DENNIS TACKLED THE ELECTRIC TRIM DEAL… (JAN 04)
Subj: Re: C209 McCauley Prop
From: Dennis Mee <meetwo@comcast.net>
Hi Jim,
The Ray Allen system I installed is fine but it is all electric, the entire cable operated system is removed from the aircraft and the servo is installed in place of the drum in the left stabilizer, even though there are no new holes introduced it takes away from a stock airplane. Since there is no back up for this system I had to demonstrate to the FAA that the Swift could be flown with the trim stuck at it’s limits under the most adverse CG conditions, it flew fine, better slower than faster! (Washington Swifter) Ernie Hansen was first to obtain a one time STC for this trim system, he did all the work and was kind enough to supply me with the data and drawings. I thought I could use his STC as substantiating data for a field approval, but about a year later and after a lot more paper work, DER costs and flight testing, I got my one time STC. The BOS ACO insisted that since I had the 210 hp engine it would be “morally irresponsible” to not require a flight test! My electric trim STC is for N3812K, s/n 3501 only, I believe other people are working on getting a multiple use STC for this trim system but I’m not sure of the progress and I think Charlie would like to pursue it as well. — Dennis Mee

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