LANDING GEAR - GENERAL

"ATTENTION KMART SHOPPERS..." (3200)
Subject: Re: Aircraft Grease
From: Steve Roth StevenRoth@aol.com
Steve:
What grease do you recommend for greasing various places on the Swift? The landing gear trunnions, Scott tailwheel, wheel bearings, etc. You recommend AeroShell Grease? What Number? I have been using Drydene "Blue" grease (recommended by several mechanics in this area). I can't find it anymore. Thanks, Steve Roth

Steve...
I use "LubriMatic" Marine Corrosion Control and Trailer Wheel Bearing Grease. Their code number is 11402. The label says, "A sophisticated lubricant developed for use in severe operating conditions caused by salt water, salt air, and/or atmospheric chemicals. Outstanding mechanical stability. Unsurpassed water resistance. Superior rust and corrosion prevention." I've been using it for everything "Swift" for about 20 years. The really nice kicker is that it is sold at K-Mart, Walmart, etc., and is quite inexpensive. Good luck... Steve Wilson <SteveWlson@aol.com>

DON'T TRY THIS AT HOME...  (040400)
Subj: Landing Gear Hydraulics
From: Bob Runge <ejectr@javanet.com>
Hi Jim:  If you move the gear lever to the up position, therefore putting the valve in the gear up position, while sitting on the ground with the master switch off and the power lead going to the hydraulic motor disconnected, will this cause the pressure in the lines to the gear to dissipate thereby possibly causing a gear collapse? Thanks. -- Bob Runge

Bob,
If you put the selector "up" and if there is hydraulic pressure present, the downlocks would disengage. The gear would probably not start up, or collapse until the airplane started to taxi. I say probably, because I never tried it! -- Jim

LANDING GEAR TRUNION ASSEMBLY...  (060300)
From: John Foster <JOHNHENRY-ANNE@worldnet.att.net>
I am rebuilding Ser# 3660 and have both new landing gear lower tube assemblies (16084) and the sleeves (16085) but now that I have it apart I find that the steel barrel lower portion of the Trunion Assembly (16108) is very rusted and pitted. I do not think that it can be cleaned out without turning a bad situation into a disaster. I discovered that there is a lot of slack in the outboard-inboard motion when I pushed it up and locked it. I do not know if this is related in any way to the groundloop which folded that gear outboard. I am having it checked out for round along the sleeve area.  I called the Parts Dept. and talked to Anthony King who advised me that they show they have two Trunion Assemblies in stock, a 16108C and a 16108E. He does not know the difference and it was suggested that I send the assemblies to Athens and they would confer with Vaughn. Also the parts in Athens were used parts and Anthony did not know anything about them. I know that I cannot be the first to have this problem so the obvious question is...What is the usual solution??? What is best solution for the longest term for the cost? Is there a "standard" rebuild or a cleanout and chrome like a cylinder? A lot of questions looking for an answer. Thank all of you for your contribution to the Swift and for any assistance you can provide. -- John Henry Foster

John,
I'm not sure I understand all your descriptions, but I have never seen the steel lower portion of the trunnion that was unrepairable. (not that it could not happen!) Too bad my physical condition does not permit, I would have you ship it here and I'm sure we could come up with something.  By inboard - outboard motion do you mean between the aluminum and steel sections of the tunnion assembly? That would be a no-no -- those pieces are usually a very tight fit. If the lower (steel) portion is rusted and pitted that usually can be cleaned up (sandblasted) and cad plated. Unless it is exteme of course. If it's rusted and pitted on the inside, that is not critical, because the brass sleeve is the important part. The outer cylinder just must have a good enough surface to allow the "O" ring to seal.There should be a fair amount of these parts available used. -- Jim

HOW TO THAW A "FROZEN GEAR SWITCH"... (080400)
From: Rich Pizzi <cece@concentric.net>
This past Saturday Aug. 5, I departed Somerset, and retracted my gear, so I thought. The gear however remained in the down locked position. I attempted to recycle the gear handle, however, it was frozen to the up position. I then thought I could solve the problem by recyling the flaps. That brought the gear up but did not solve the frozen gear switch. The emergency crank would not work because of the location of the gear switch. I flew around for about 30 min. with my hand behind the panel attempting to feel what was freezing the handle. I eventually felt something fall in place freeing up the gear switch. The mechanic thereafter discovered that the gear switch rod had somehow slipped above the toggle switch causing it to go too far up and freezing the switch. HAS ANYONE HAD THIS PROBLEM BEFORE AND WHAT IS THE BEST WAY TO PREVENT THIS IN THE FUTURE? Rich N2328B

Rich:
I spent some time trying to visualize the panel in N2328B - of course it may have changed since I last saw it. When Swift panels are modified one of the first things that is discarded is the plastic that the factory installed near the lower edge - including around the gear and flap handles. If that plastic is not there, providing a spacer, the gear and flap rods can be pushed forward far enough to make the switch miss it's actuating lever which is welded to the rod. This same thing could happen if there is extreme wear or the lever has gotten bent. The switch can be worn or disintegrating also, after all it's over 50 years old now and very few of them have ever been replaced. If the plastic is there, providing a spacer, and the switch is in good shape, and if there is nil wear, the system is very reliable. If your plastic is gone, a spacer can be made. I believe it might be about 3/8" thick with a hole the diameter of the gear and flap rods. My congratulations on doing the right thing and reaching up under the panel until you got the desired results!  --  Monty

MONTY WAS RIGHT ABOUT WHY THE LANDING GEAR HANDLE WAS JAMMING... (080600)
From: Rich Pizzi <cece@concentric.net>
Monty:
Sorry for the delay in responding. Your help is very much appreciated. You were right - that plastic spacer keeps the gear handle rod from slipping above the toggle switch and jamming. My mechanic has now fixed the problem. This could have been really serious since the locked up gear handle prevents the emergency extension from turning. Once again thanks for all of your help!  Rich - N2328B

SOLVING A PUZZLE...(120200)
Subj: Landing Gear puzzle
From: Steve Whittenberger <jssjwhitt@email.msn.com>
Jim, Just finished my annual with the help of Ray Brown. Bird was is pretty good shape but did a little tweaking and cleaning up -- preventive maintenance stuff. Landing gear (Adel) was working well but when up on jacks it indicated that the upper trunion bushings needed replacement. Job was done as well as replaced the long emergency gear extension cable. Now the problem. The gear worked well in all respects during the jacking process and timing was good -- about 5-7 seconds for gear retraction. The problem arose when I flew the bird. The left gear would not come up. Adjusted the cable to a longer length and the right gear would not come up. We have redone the alignment and adjustments three times and flown it each time with the same results. Gear will not come up with air loads on it. The pump will run for about 10-12 seconds and then it will trip the circuit breaker. Gear extension (normal or emergency) can be accomplished with no problem. Next we attacked the pump to see what the output really was. We got 500psi on both ports. So we believe the pump is strong. (I have always gotten gear retraction in 5-6 seconds or so and many who have ridden with me have remarked at how fast the gear was)

Right now we are scratching our heads. We have adjusted the new extension cable a few times but that doesn't seem to have any effect one way or the other. Hmmmm............. Any thoughts on this? We have been through all the Swift and Hydraulic manuals and I researched all your previous writings that I have at my disposal. Anybody run into this before? Many thanks for your thoughts and ideas. Cheers, Steve Whittenberger

Steve,
The first thing I thought of was, perhaps those new trunion bearings are too tight. Does the gear swing freely? If it does, check that you have all the hydraulic plumbing connected properly and then back off the emergency extension cable and make sure the gear operates OK on jacks. Have you had a battery charger or jumper battery connected when operating the gear on jacks? Perhaps your battery or generator is weak. Did you do other work at the annual? If everything else checks out it sounds like there could be some internal leakage in an actuator or in the hydraulic power pack. -- Jim

ED LLOYD ALSO HAS SOME ADVICE FOR STEVE...(120200)
Subject: Re: Landing Gear puzzle
From: "Ed A. Lloyd" <edlloydaustin@juno.com>
Steve, for what it's worth.........when I had my gear off last winter and reworked them, I noticed the trunnion tubes were egg shaped on the ends and this made the individual gear leg sloppy in the partially retracted position while on jacks. The gear was moving fore and aft greater than the limits mentioned in the manual and the AD 51-11-04. I went to Joe Ranson for parts and he suggested I rotate the trunnion tubes 90 degrees, drill a new hole for the thru bolt and see if the "play" would disappear. I did that as well as replaced all the bushings that were out of tolerance which was all of them. Especially the two trunnion or tube bushings. (Part #16117 on page 17 in my parts manual). I assembled the tube into the gear leg and rotated it by hand to feel for any tight spots and I found some. I kept working the problem until the binding was gone, hung the gear and before the side braces were attached, I made sure the gear swung freely up into the well. All this done, I completed the assembly and everything worked fine. When you say one gear stays down, are you saying or do you know, is it unlocking and trying to move at all? Has Ray observed from the ground or in the air? There are some VERY close tolerances between the actuator arm with the emer gear cable drum on it and the downlock actuator housing. I have observed more than one Swift with scrape marks on the emer cable drum on the actuator arm caused by interference with the downlock actuator. Bottom line of my theory is, maybe the air loads are causing this close tolerance to become NO CLEARANCE and the gear wont move out of the down position because it's bound and can't go up. Know I'm preaching to the choir but then again, maybe from a different sheet of music. Good luck.........Ed

LANDING GEAR PUZZLE CONTINUES...(120200)
Subj: Re: Landing Gear puzzle
From: Steve Whittenberger <jssjwhitt@email.msn.com>
Jim, Agree with the thought of the bushings being too tight. We did then swing the gear and it came down freely with no apparent hesitation. All the hydraulic plumbing is connected and in the right place. I did back off the emergency cable but only about 3/8"-- maybe that wasn't enough. However, the tension on the cable when in the normal preflight mode is pretty loose. Don't want it to get so loose it comes off. Expect it has about 15-20 pounds on it. Didn't check it with a tensiometer. Battery is ok and plenty strong enough to run the gear at this time. We did replace all the bolts on the gear hinges but they seem to be ok as the gear doesn't bind and will swing freely down. The gear hydraulic is tight at the gear and I have no leakage or seepage. Guess that leaves internal leakage in the power pack. Hmmm. Guess I can get a kit from Swift parts but as I recall from Joe Ransom it is a bit of an art in doing that job correctly. Ray may be able to do it. We'll keep working and let you know. Many thanks for the swift and informative reply. Cheers, Steve

Steve,
Before you get into the power pack or actuators, run the gear on jacks again. Manually attempt to hold on to one of the gears, preventing it from going up. Can you stop it easily? If so, you might be able feel or hear the fluid bypassing the "O" ring on the piston in the actuator. If you measured 500 psi at the outlet ports, I would not think the leakage is in the power pack. You can manually retract the gear by pushing the downlock in with a screwdriver and then pushing the gear "up". Do this to check free operation. Your problem sounds like it may be as simple as low hydraulic fluid quantity. Are you sure you have the correct amount of fluid in the reservoir? --Jim

LAST LANDING GEAR PUZZLE THIS ISSUE...(120200)
Subj: Re: Landing Gear puzzle
From: Steve Whittenberger <jssjwhitt@email.msn.com>
We have checked the hydralic fluid several times and even after some of the extensions/retractions. Something I did find was one of the gear doors (original) was somewhat loose and though the gear works on the ground the airloads may be pushing it around to act as a speed brake. We tightened it and aligned it perfectly ......now. So I guess I'll have to suck it up and go fly and see if that was the problem. I am just trying to do everything I can to insure success. As long as the emergency extension works okay I should be fine. However, I have not had a problem with the normal extension. Just don't want to leave anything to chance and screw up and land gear up. That would really ruin my day.

Steve,
Good luck and be sure the emergency extension works before you fly!  --  Jim

LANDING GEAR PROBLEMS? BLEED THE AIR OUT..(120300)
From: Harry Asbury <gypsyone@tds.net>
Subject: Re: December #2 GTS Internet Update
Dear Jim, I'm not up to date on the Swift's hydraulic system, but I've had a lot of experience on other hydraulic systems and one that has happened to me quite often was to have some part of the system not to work under load, such as the gear retracting in the air, but works fine on the ground. I have found in most cases when I can't find anything else wrong with the system, that there is a little air in the system and it will compress enough to stop the actuator from performing to it's maximum limits under load. The solution was always to bleed the system simply by jacking the aircraft and actuating the gear at least twenty times. The way the actuator is mounted in the aircraft sometimes lead it to trap air and it's awful hard to get it out. Just a thought on the gear retracting problem. -- Harry

Harry,
Good point. If I were working on Steve's aircraft I would have cycled the gear numerous times on jacks. I assume Steve and Ray also did this. When I am trying to help via email I don't know if they for a fact did that. Air in the system will indeed cause symptoms like what they are experiencing. The Swift system will usually bleed itself out after a few cycles. -- Jim

MORE FROM HARRY ON THE IMPORTANCE OF BLEEDING THE HYDRAULIC SYSTEMS...(120300)
From: Harry Asbury <gypsyone@tds.net>
Many a time I would ask the military did they bleed the system and all ways they would say yes! I have found that they would give it a half hearty try and in some cases on the larger hydraulic systems they would never get all of the air out. I know on the SH3s and HH53s this was a problem with the landing gear. I've even seen it in the rescue hoist systems. In that case it would cause a chattering on the up cycle with a weight on the hook. The big internal winch system wouldn't even pull the cable in if there was the slightest air in the system. I've even investigated fatal crashes where the control system wasn't bleed properly and this caused the pilot to get out of sync with the cyclic stick to the response of the aircraft to the controls. It got so bad as that he was 180 out with the response and crashed into the sea. I didn't figure that one out until four years later when the same thing happened to another of the same type aircraft and believe it or not, the co-pilot on the fatal crash was the command pilot on the one we got back. Once on the ground, I tried the controls in a low hover and right away I could feel the spongy respond and knew it was air, due to a auxiliary servo change in the aircraft the day before. They had failed to bleed the complete system. This gave me the answer to the fatal crash. The same type of maintenance had been performed on the fatal crashed aircraft. I guess if you stay in this business, you will eventual see the same thing occur again down the line. Pardon my long winded message, but I have always loved working and solving the little mysteries of maintenance. -- Harry

STEVE'S THOUGHTS ON THE LANDING GEAR PUZZLE FROM LAST UPDATE...(120300)
From: Steve Wilson <SteveWlson@aol.com>
Subject: Re: December #2 GTS Internet Update
In the last update...
<< We did replace all the bolts on the gear hinges but they seem to be ok as the gear doesn't bind and will swing freely down. >>
My first impression is one of a gross internal leak. Jim's suggestion of holding the gear and see if you can stop it from retracting should prove that one way or the other. I occurred to me... One time I went to pick up a Swift (N78083) from an annual (not done by Swift mechanics). It was at night and one gear did not retract (acted like you say, partial retraction, then in about 20 secs blew circuit breaker). It did extend OK though, so no big sweat. What I found was the bolts in the lower scissors had been replaced and were one size too long. My guess is there was enough "play" in the system to allow them to pass on jacks, but air loads prevented one from making it during flight. Just a thought...

LANDING GEAR SCHEMATIC ERROR...(020501)
Subj: Documentation Error
From: Steve Thompson <sthomp@swlink.net>
Jim, I've been chasing a gear light problem (red gear up light won't come on...but white operates normally and goes out OK when gear is up). But this is something that I have to solve myself. It does not lend itself to an "internet solution". However, in my pursuit of the problem, I'm pretty sure there is an error (besides the ones already documented and corrected in the Commings Hydraulic Manual)...in both the Swift Owners Manual and the Commings Manual. It relates to fig. 32 on pg. 77 of the former and the same schematic in the Hyd. Man. (no pg or fig). The error is that both of the L.H. Landing Gear Limit switches (down limit and up limit) are shown in the wrong position...the center arm should be pointed to the upper contact of each switch...to be consistent with the gear in the DOWN position. It is also intuitively indicative that this is the case since the two R.H. switches are mirror images of the two L.H. switches...yet the center arms are not mirrored. The real clincher is that it just won't work the way it's drawn. Maybe this is old news...if so, dump this and open another Michelob... Steve

Steve, Your gear light system has evidently been modified. The original system had a green light for "down", a yellow light for "in transit" and a red light for "up". The error on the original wiring diagram is well known and I'm glad you spotted it yourself. There are several gear wiring diagrams in the blue book "Maintenance and Operation Information for the Swift", published in 1987 and available thru the Swift Association. If you don't have this book, get it! Also, read the "Monty the Answer Man" archive in the Swift site. Some of the earlier answers are not as good as the definitive answer Ron Williamson gave on the subject of relays. The Commings Manual also has several useful wiring diagrams. I'm glad you got in contact with Joel Sampson, he is an excellent Swift pilot and instructor. I don't know if he has kept his CFI current, but I'm sure hehasn't forgotten how to fly a Swift! -- Jim
PS - I like Heineken's over Michelob!

SAVE THOSE RETRACT ARMS... (040201)
Subj: landing gear
From: Mark Gallicano <sharky@rctvonline.net>|
Hello Monty : I have a question about my retract linkage . the actuator - arm #16030 and the crank 11-313-2302-2 are wearing egg shaped on the link assembly end. can an oversized bushing repair the wear or are they toast . thank you, mark gallicano sharky@rctvonline.net

Mark
Don't throw away worn retract arms! They can be bushed to be as good as new. Even bent arms can be straightened. They are very mallable and hardly ever crack. -- Jim

SOMETHING EVERY SWIFT OWNER SHOULD HAVE...(040501)
From: George McClellan <WWIIPILOT@aol.com>
Are the bushings easy to find for the Adel landing gear side arm links? I have some play and intend to replace the bolts. The long connecting bushing looks OK. I hope you can tell what I am talking about. The side arms that allow the gear to retract.

George
Swift Parts has a bolt and bushing kit that every Swift owner should have. You can use whatever bushings are required whenever you need them. I buy a new kit every few years. It's always nice to have spares on hand. -- Jim

WHAT'S THAT CLICKING SOUND... (050101)
Subj: Re: Landing Gear question
From: sthomp@swlink.net (steve thompson)
Jim,
I finally got my jacks and today I did the retract test. The "up" time was 9 sec. and the "down" time was 5 sec. There were a couple of anomalies that I hope are SOP... 1. going up, both struts start up together, then the left stops about 3/4 up and holds there until the right is completely up, then it finishes. 2. going down, the first several cycles the right strut went completely down before the left started down...then after several cycles the order reversed, with the left going down first. The question is...is it normal for the sequence to change...and, does it matter? 3. when the gear is up, pump off...there is a sound like a clock ticking coming from behind the panel. (never able to hear this previously due to engine noise). This does not happen with the gear down, master on. Please tell me all this is normal so I can move on to other issues like fixing the fuel tank leak and replacing the vert. stab. (corrosion...both the previous owner and the A&P who did the annual in Dec. assured me of no corrosion. I'm going back up to Don B. when I get all the parts together). Thanks, Steve

Steve
It makes no difference which gear goes up or down first. If one gear has more drag, like a tight bushing, it will take more force to operate and go slower. And if one actuator is more efficient it may operate faster. Or if one actuator has a worn "O" ring and thus more internal leakage, it will go slower. The clicking noise behind the panel likewise is normal. The gear is up, right? And the throttle is closed, right? The gear warning system thinks you are flaring out to land with the gear up! Advance the throttle a little and the clicking will stop. -- Jim

JOHN’S EXCELLENT LANDING GEAR ADVENTURE CONTINUES... (120101)
Subj: More Gear Stuff
From: John Cross <crosses@houston.rr.com>
Jim:
Does anybody replace the aluminum plumbing in the gear well with flexible lines? I want to eventually replace one and it looks hard to fabricate since it shaped like a drunken pretzel. -- John Cross N2398B

John
Why don't you want to file that corner off? That's the way Mr Commings used to do it at Univair. Wobble on that plate is normal and it would be bad if you got it fitted up too tight. It is very easy to bend soft 1/4" aluminum tubing for the hydraulic lines. I would not recommend you substitute any other material. -- Jim

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