EMERGENCY EXTENSION CABLE SLIPS OFF PULLY…
From: gi@lucent.de
Subject: Re: Emergency Gear extension
Hi Monty,
I wanted to go flying last weekend and during the preflight check I found the right emergency gear down cable has jumped of the actuator-pulley (the one where the gear is). Playing a little bit with it I found that it could have come loose because of some friction (it needs grease) in the routing (all the pulleys in between) when I was lowering the gear the last time.
Do you know of similar experiences? Regards — George
George:
Yes, this is quite a common occurrence. There are several things that can be done. First, make sure the system is lubricated and operates freely. Univair used to sell a cable guard ref. SB #35, I don’t know if Swift Parts still has these or not, but it is a worthwhile thing to have. I would say having the Service Bulletins is a MUST! A cheaper, and perhaps more effective way to keep the cable on the pully is to drill the actuator pulley and install some .032 safety wire. The details of this are in a book published by the Swift Association many years ago. You should also have this book. It is available from the Swift Association. — Jim
LANDING GEAR EMERGENCY EXTENSION… (3699)
From: Steve Roth (StevenRoth@aol.com)
Subject: Re: Cable Gear Extension
Monty:
I don’t know if it is possible in short words but how does the cable emergency gear extension work? I see that when you turn the crank, it is turning a large screw. The other thing I know is that a central pulley is used to pull up the cable (in the middle of its entire length) to put pressure on the two sides of the cables that go to the actuators (thru a series of pulleys). What I don’t understand is this: With the gear emergency in the normal position, how does that central pulley ride up/down as the gear is actuated hydraulically? Is that pulley attached to a ring which rides up/down over the screw shaft assisted by a spring? So, when you do crank the emergency gear crank, it screws up a sleeve which pushes on the underside of the sliding ring and that pulls up the pulley?
Steve,
Well, I don’t know how good I can answer this from memory off the top of my head but……..There are 2 stationary pullys that change the direction of the cable 90 degrees, and another pulley which “pulls up” on the screw when the crank is turned, this in turn pulls the gear down thru a drum on the gear actuator OK – see the spring on the pull down screw/shaft assy? This allows the big pulley (sleeve assy) to ride up and down under normal gear retraction/extension. The best thing to do would be to watch it next time you have it on jacks and cycle the gear. — Monty.
EMERGENCY GEAR CABLE…(6399)
From: Jerry Swartz <JSw7211963@aol.com>
Subject: Re: Gear Cable
Jim:
Last preflight, found gear cable off of large actuator pulley. Moved cable guard, reinstalled cable on pulley, and then moved cable guard back in place. When this happens, should the airplane not be flown or is this a somewhat common happening. The cable does have a kink or two in it. Jerry S.
Jerry:
I suggest you look the cable over closely, (remove the upholstery by the gear crank) then add the .032 safety wire per the Commings Hydraulic Manual and the “Maintenance and Operation Information for the Swift.” If there is doubt about the system, the airplane should be put on jacks and the gear cycled, normal and emergency. The cable will not come off IF the pull down jackscrew is properly lubricated and if the cable guards are in place, which they obviously weren’t in your case. Be happy. You found the problem on the ground, where it really isn’t a problem! — Jim
EMERGENCY GEAR EXTENTION vs HYDRUALIC FLUID… (7299)
From: edlloydaustin@juno.com
Subject: Emergency Gear Extension / Reset / Retraction
Recently I had Duane Golding do a pre-buy inspection on a Swift for me. I wanted to do the emergency extension for the experience, never having done one. Followed the checklist, put the gear down with the emergency crank and everything worked as it was supposed to. “Un-cranked” the emergency gear system and replaced the safety pin. Then we cycled the gear a few more times, for the IA that was present, and hydraulic fluid came out the breather cap of the gear/flap reservoir and ran all down the firewall. The reservoir was not over serviced. My question is why? Duane said every one he has ever done, bleeds fluid out of the vent after an emergency extension/ reset / and subsequent normal retraction. Would appreciate your comments. Cheers….Ed Lloyd
Ed:
After giving it some thought… First, don’t worry about it. Just cover the reservoir with a rag and let it try to keep the mess to a minimum. To have a low fluid level in flight is BAD and to try to keep the fluid level low enough to avoid overflow is not worth the effort and subsequent risk of nonfunctioning gear. Incidentally, a too low fluid level will prevent the gear from going up, but it will go down, and the flaps will operate. What is happening is the volume of fluid coming back to the reservoir from the actuators is greater than the reservoir capacity. Back when I was an A&P school instructor I made a mockup with an F-84 hydraulic system. If I had the time and inclination today I could do the same with a Swift hydraulic system and figure out exactly why the excess fluid doesn’t go to the extend side of the actuator. But I am willing to accept how it works and am not losing any sleep over it! — Jim
PS: As I sent the previous mail it occurred to me, with the hydraulic pump not operating and the fluid being displaced from the actuator by the gear being pulled down the reservoir is going to overfill. The fluid can’t get to the “down” side of the actuator.
Some additional thoughts on this subject from Don Bartholomew…
The situation you have described has happened to me many times. First, the fluid generally squirts out when the gear is being cranked down. You may not notice it until a short time later (eg another cycle or two). This is because an excess amount of fluid goes back to the reservoir due to none being pumped into the downs side of the cylinders.
There are a couple of things that cause this. First is over full on the fluid level. Some of the original pumps had a dipstick on the aft side of the reservoir, some did not. If fluid is added to the elbow on the front of the reservoir, even though the elbow is at the same level of the “full” mark of the dipstick, you are overfilling the unit. This is because in the three point attitude, the elbow is higher than dipstick giving an inaccurate indication. Typically I have found that if the power pack has a dipstick and the fluid level is between the indicator holes or marks, the spraying during emergency crank down does not happen. Another thing that can cause the problem is originally there was a flat, tin splash plate in the pump that deflected the return stream of fluid from spraying onto the top of the pump (right where the breather hole is). Sometimes I have found that when the power pack was resealed, the plate left out.
A suggestion for filling the power pack. If there is an elbow on the front of the unit, lift the tail to the level flight position and then add fluid until the level is at the BOTTOM of the elbow. If the elbow is a little loose, fill the reservoir and unscrew the elbow half a turn so the excess fluid runs out. Happy 5606 cleaning! — Don and Helo
EMERGENCY GEAR EXTENSION… (11199)
From: Steve Roth <StevenRoth@aol.com>
At annual in August I inspected, cleaned and lubed the emergency gear extension system. I used light grease on the shaft and extension crank screw. Shortly after that I talked to Joe who said not to use grease on the mechanism since during cold weather the grease could stiffen and prevent the mechanism from working. That made a lot of sense so I degreased the mechanism with solvent. Then I relubed it with spray lube (WD-40).
In late October I was doing the preflight check of pulling on the emergency gear extension cables in the wheel wells. I could pull the cable out but they would not spring back. So, I took the cover off the mechanism in the cockpit and could find no mechanical reason the cable would not wind back. So, I again degreased/cleaned the mechanism thoroughly (using a half can of spray brake cleaner in the process) then lightly lubed it with a few drops of high quality gun oil. That fixed it.
The next day I did the preflight check again and the right emergency control cable was frozen (would not pull out). I took the cover off the mechanism and found the right cable had become stuck under the aluminum brace which it usually rides on. Each side has these aluminum braces and they have fiber “plates” riveted to them on the front as rub plates for the cable. Somehow the cable had gotten stuck underneath this brace, probably from allowing too much slack to form in the cable. Investigating this condition, I found out the importance of having the safety wire “clamp” modification to the crank/pulley on the gear actuator in the wheel well (the large one where the end of the cable is anchored). This modification is mentioned on page 9 of the Blue book – “Pull Down Cable Fix” (Maintenance and Operation Information for the Swift). That safety wire “clamp” prevented the cable from coming out of the groove and off the actuator pulley. With slack in the cable when the gear is extended, the cable would definitely have come off the pulley. Thus, if that cable came off the pulley when the gear was retracted, the cable would have gotten tightly snarled somewhere outside the groove in that pulley, either jamming it or eventually breaking it. What did I learn:
(1) Keep the gear emergency system clean and degreased. Lube the mechanism lightly with thin oil products, not susceptible to thickening in cold. Follow the procedures in the Blue Book. I intend to do this several times between annuals.
(2) Perform the cable check in the wheel wells at every preflight.
(3) When performing the wheel well check, pull out the cable and let it slowly retract under spring pressure. Don’t pull the cable out and let it spring back — it may get jammed under the brace, as happened to me. If it binds in any way, investigate the problem.
(4) If not already done, install the modification to the extension pulley that uses safety wire to hold the cable in place (per page 9 of the Blue Book).
I pay particular attention to the gear extension system since on my solo flight after Swift check out the gear motor failed and I had to crank down the landing gear. Just reinforced that after this episode, extra care is necessary. Thanks, Steve Roth & N2397B
SWIFT EXPERTS RESPOND TO A CABLE… (030600)
From the Yahoo! Globe Temco Swift Club:
The emergency gear extension cable came off of the large pully at the upper part of the strut. Though I put it back on, it remains somewhat lose. Could I tighten it by cranking the emergency handle counter clockwise? or Clockwise? while the plane remains on the ground. Thanks for your help. — Rich Pizzi <cece@concentric.net> N2328B
Rich:
The first thing that should be done is to get the airplane up on jacks and to make sure the system operates properly. There are several items which will keep the cable in the groove, one is a cable guide, SB #35, the other is a simple addition of a loop of .032 safety wire, see the Commings Manual. If the cable is too tight in the “down” position, it will be too tight and possibly break in the up position or pull the pully brackets off the spar web. DO NOT CRANK THE SYSTEM PARTIALLY DOWN TO TIGHTEN UP THE CABLE — Jim
Rich…
I know everyone talks about the “Maintenance and Operation Information Manual” available from Swift Parts, but who reads it? Please!!!! Get a copy… On page 10 it covers what is most likely your problem, i.e., “Emergency Gear System Lubrication.” Just in case you do not have a copy handy, in part here is what it says… “The most common complaint is the cable was off the pulley someplace. Lubrication of the worm gear assembly and regular thorough check of the entire system usually eliminates most of the problems… .” Whatever you do, Rich, do NOT operate with the cable partially retracted!!! Check the worm gear and spring. Make sure they are clean and well lubricated with “light” lubricant (NOT grease). Make sure it is not in contact with boot (upholstery) covering the front spar. Check it once in a while (at least at each annual). May the force be with you… Steve Wilson <SteveWlson@aol.com>
Rich,
I’m reading something in your message that the others have not mentioned. Study the gear system and especially the emergency pulldown so you know what’s happening in your aircraft’s system. Put the airplane on jacks as Monty has suggested and pull the bottom panel under the spar area. Secondly, pull the panel of the floor just in front of the seats. That exposes the emergency pull down mechanism below the emergency crank down handle. You get under the airplane and have someone (using checklist) crank the gear down for you so you can see what the emergency pull down system does for you. UNCRANK the system and cycle the gear using the normal gear system. Then you get in the cockpit and do the emergency crank down using the Emergency Pull Down Checklist yourself. Have someone watch from outside to tell you when the gear downlocks are locked on BOTH gear. This way you can see the emergency pull down do it’s thing from the bottom and the top as well as FEEL the pressures involved in cranking the gear down. You will have an appreciation for what the simple system does for you. If you ever have to crank the gear down you will understand what is going on and be a better Swift pilot in the end. Also, follow the suggestion to clean and lube the jack screw so the sleeve assembly (PN 2882) moves freely during the cranking operation. Look in the Swift parts manual on page 12&13 and you can see how the system is put together. Another hint, when you preflight, pull smoothly down on the emergency pull down cable a couple inches in each wheel well and release the cable slowly back to it’s proper location. This will give you an idea of how the cable routing is working and may disclose whether the cable is off the pulleys somewhere in the system. Hope this helps you understand your bird better. Added note: Plan on coming to National this year and attend the maintenance seminars. Wealth of information discussed there and IT’S FREE. Ed Lloyd <edlloydaustin@juno.com>
Rich,
Hoping to not appear that I am piling on —– I had similar problem with slack gear cable. It began with the pulling on the emergency gear cable in pre-flight. Cable would not go back smoothly so I examined the screw mechanism. I had some grease on it and cold weather had made it thick. The idler pully that rides up/down on that shaft would not move freely, so the spring would not keep the cable tight easily. So, I completely degreased the mechanism and used only light gun oil to lube it. That did the trick. But, then, while doing all of that I managed to get the cable beneath a stringer as it passes to the wings and it eventually got jammed, got some slack in it and came off the large pully on the actuator. Fortunately, I found that condition as I did my preflight by checking the gear cables. What really saved the day was the modification of adding the safety wire recommended in “the book” had been done. That prevented the cable from really getting jammed.
I wrote this up and Denis published my whole story in his electronic newsletter several months ago.
The bottom line for me was (1) keep the mechanism cleaned (several times a year) and lubed with light gun oil; (2) make sure the safety wire modification is installed; (3) when checking during pre-flight if you pull cable out to check for free movement let it go back slowly so as not to “jump” and get caught on anything. Steve Roth <stevenroth@aol.com>
EMERGENCY GEAR CABLE TENSION… (040500)
To: Dennis Mee <jmmee@nh.ultranet.com>
Hi Jim, My question is how tight should the emg ext cable be when the gear is retracted? I can pull the left gear down with the hyd system depressurized, it takes a good pull but it will unlock. The emg ext cable is pretty tight with the gear up so I intend to loosen it but don’t know how far to back it off, any suggestions? Thanks, Dennis Mee
Dennis,
The pull down cable gets pretty tight. If you can pull the gear out with the selector “up” but with he system depressurized, it may not be going over center enough. The cause is usually that the teeth on the rack are mis-indexed on the gear in the actuator, (one tooth off) or the pull down cable is too tight. Before you tear out the actuator back off the tension on the pull down cable. Back it off enough that the gear won’t crank down and lock, then add just enough tension so it will. The right amount of tension is the minimum amount that will get the job done. I presume you know that it takes approximately 52 turns of the crank. Be sure the screw does not unthread. Read the service bulletin on this. (the serial numbers in the service bulletin may not be right) — Jim
FEDS APPROVE… (050100)
Subject: Landing Gear
From: Dennis Mee <jmmee@nh.ultranet.com>
Hi Jim, The fed’s finally showed up today, they inspected the installation but did not care to see it operate, they took my word for it. I’ve mailed you a copy of the approval just to keep with your records, the final package was about six pages with pictures, and a copy of your approval. The good news is that my new PMI will be a lot easier to deal with then the present one. I checked the LG adjustments IAW SB #7 & #28. Item #9 of SB #28, for s/n prior to 3501, (N3812K is s/n 3501) calls for a gear-up pull down cable tension of 90 -100 lbs. AD 51-11-4 (every annual or 100 hrs) applies to all s/n, so I backed off on the pull down cable tension a little and that solved the up-lock problem. Now all I have to do is get the strips painted and she will be ready to fly!!! Thanks again for all your help, sometimes the paper work is the most difficult part of the job! — Dennis Mee
DO IT ON THE JACKS… (050200)
Subject: Re: Hydraulic Pump Motor
From: Phil Howell <POPPAPOU@aol.com>
Jim: Question: Is it a no-no to test the emergency system in the air now and then in addition to the tests on jacks? Thank you for your help. Phil >>
Phil,
I wouldn’t say it is a no-no but I wouldn’t do it. If something malfunctions, you probably would end up with a belly landing. It’s better to test it on jacks, where any error (human or mechanical) is easier to correct. — Jim
PULL DOWN CABLE ADJUSTMENT STOPS GEAR PUMP MOTOR CYCLE… (060300)
Subj: Electric Gremlins
From: Peter Kailey <kailey@sunri.com>
Monty,
I am a rookie Swift owner and am learning much already from the group. My Swift has a panel mounted Apollo GPS that was pronounced to be “intermittent” by the previous owner. In monitoring the unit in flight, the problem does not seem to be in the GPS, but rather in the power source. What happens is that every few minutes in flight, the “gear pump” light comes on for a split second. At the same moment, the ammeter shows a very large drop in voltage, again for just a split second. The “gear up” light does not flicker during this moment, however. As soon as this occurs, the GPS goes into it’s startup sequence, just as if it had been turned on. (The digital Nav/Com is not affected.) This event occurs more often in rough air, and I must confess I have not noticed if it occurs when selecting “Gear Down”…I seem to be too busy to look just then. While I suspect that the answer may be to add the filter or capacitor you mentioned concerning the fuel totalizer problems of another member, I also am wondering why the pump light should come on for that split second. It doesn’t seem to come on long enough to actually do anything…is there some adjustment in the switch that could be a simple fix? Peter Kailey
Peter,
I think you have the answer to your GPS problem. All we have to do now is figure out why the pump motor comes on in flight. Obviously, the gear is falling out far enough to activate a microswitch. With the airplane on jacks and the gear up, turn off the circuit breaker switches. Make sure there is no pressure on the hydraulic system by operating the flaps. Place the gear selector down. If one gear comes out, or can be pulled out, the actuator arm may be mis-indexed with the gear in the actuator. (one tooth off) Or the pull down cable may simply be too tight. Read the service bulletins. Perhaps you can get by adjusting the microswitch so it doesn’t click. (providing the gear doesn’t come all the way out of the well) Dennis Mee had some gear problems recently, maybe he has some hints for you. — Jim
WELL… IT JUST SO HAPPENS THAT WE DO INDEED HAVE SOME HINTS FOR PETER FROM DENNIS MEE… (060300)
Hi Peter, Monty copied me in on your gear problem, I had a very similar problem with the pump coming on in flight causing a voltage spike on the radios. I determined the problem was with the left gear by turning the hyd pump motor off in flight and letting the speed build up in a shallow descent then with a gentle pull up the left gear came out, I have the external “curb feeler” indicators on the gear doors so I was able to see it was the left gear, after slowing to 80 mph I retracted the gear and pressed on with my flight. The same thing can be accomplished on the ground with the airplane on jacks by following Monty’s directions:
Make sure there is no pressure on the hydraulic system by operating the flaps. (manually – with the hyd pump motor off). Place the gear selector down. If one gear comes out, or can be pulled out, the actuator arm may be mis-indexed with the gear in the actuator. (one tooth off), Or the pull down cable may simply be too tight. Read the service bulletins.
I followed Monty’s directions and found that with a hefty pull the left gear would come down, but it took a good pull. I had already replaced seals in any actuator that had the slightest leak in the entire hyd system, and the travel on the gear actuator looked ok so I focused on the pull down cable. Following the advice of Monty and Steve Wilson this is what I did: with the Swift on jacks and the gear down I loosened the pull down cable turnbuckle in the left wheel well until the cable had no tension on it, (about five or six turns). I then retracted the gear, when the gear is up and locked take the hyd pressure off the system as Monty previously described and try to pull each gear down, if they both stay up, then extend the gear and tighten the turnbuckle one turn and try it again. You may have to do this several times, tightening the turnbuckle until it is just loose enough to keep the gear locked up. Once you have the correct cable tension set so that the wheels cannot be pulled down you will have to check the operation of the emergency gear extension system. Caution never retract the gear unless you are sure the pull down system has been reset, (cranked back up)! With the gear up and the hyd pump motor off place the gear selector lever to down, crank the gear down (about 52-54 turns), when you have finished cranking check the over center side brace links and the hyd down locks IAW AD 47-06-01 (due every 100 hrs or annual inspection) and Swift service bulletin # 7, if this is ok, with the gear lever down turn on the hyd pump motor and gear switches to check for proper light indications. This would be a good time to reset the pull down system, (crank it back up if you haven’t done so). AD 51-11-04 (due every 100hrs) and Swift service bulletin # 28 address the pull down system, don’t forget to check for the spacer, I was recently helping someone annual a Swift and found that did not have one installed, this was a very well maintained and documented Swift. You may want to charge the battery before you return the Swift to service. This solved my problem and is not as complicated as it sounds.
I’ve sent a copy of this to Monty so he could make any corrections or additions, he knows far more about Swifts then I do, but if I can be of any help just let me know. Good Luck, Dennis Mee
EMERGENCY PULL DOWN CABLE SHOULD BE TIGHT AS A “G” STRING… (100400)
Subj: Pull down cable
From: Sheridan Owens <Sandb12345@aol.com>
My emergency pull down cable broke during a gear swing. was rusted a little bit. put in new cable and pulled the gear up the cable is tight as a “G” string adjusted to pull the locks at turn and a half as per blue book. but still seems tight. is this normal??? thanks. Sheridan Owens N80776 sandb12345@aol.com
Sheridan,
Yes, when the cable is adjusted right and the gear is cranked down it seems VERY tight. — Jim
HOW ONE SWIFTER SOLVED THE EMERGENCY EXTENSION CABLE TENSION PROBLEM… (100500)
From: Porter Houston <phouston@erols.com>
Subject: Emergency cable G String Problem
I solved the cable tension problem many years ago with two very minor modifications to the original design of the gear emergency extension system. The original design, as a concept, is good except the design cable travel is actually less than what is required for gear up/ gear down positions. Basically the jack screw is too short. Also, a spacer at the bottom of the jack screw( required by AD) reduces travel even more. Therefore, the correct cable adjustment is so critical there is even and AD note on how to do it. Also, the tension on the cable has to be excessively high because just as it goes into down lock there is alot of extra force required. This translates into very high cable tension in gear up position. The modifications address these two problems.
(1.) increase the available cable travel. (2.) decrease force required (read cable tension) to pull into down lock position.
Mod #1 : To increase available cable travel cut the cable groove in the pulley deeper by 1 cable diameter. I used a wire saw blade available from local hardware stores and using a shoe shine action to deepen the groove. The side benefit is that the cable rides deeper in the groove and doesn’t pop out and therefore the original simple cable guard bracket is all you need. I also adjusted the up stops and micro switches as far out as required so gear doesn’t over center in up position and gear doesn’t fall out of gear well in flight.
Mod#2: .To reduce the force required to pull into down lock I replaced the AN315-3 nut that locks the #10 socket head adjustment screw with a AN365-1032 elastic stop nut installed backwards. The extra thickness (use washers as required) of the AN365 nut eliminates the space between the head of the socket head and the old nut. Originally the down lock lever would fall into this space and the extra force was needed to raise the down lock lever over the head of the screw into position. Plus the AN365 nuts tapered diameter creates a ramp for the down lock lever to fall into position almost on its own.
These two mods allows you to significantly reduced the gear up cable tension and still guarantee gear down lock when you need it. — Porter Houston
SWIFTER DON ON THE EMERGENCY EXTENSION CABLE…(010502)
Subj: Gear extension cable
From: DON THOMSON <swifterdon@attbi.com>
Hey Monty:
I was reading your response in the GTS newsletter to Jack Gladish about the tension on the emergency gear extension cable. I thought it would be worth sharing the experience I had with Charlie Hopkins when we did my last annual. During the gear emergency extension check we found that the left gear leg fell from the wheel well immediately after placing the selector in the down position, but before we started cranking on the handle. I remember you telling me that the condition was a symptom of the cable was too tight. We continued to play with the tension until we could place the selector lever in the down position, with the circuit breaker pulled and the gear would stay in the wells. We found that the difference between being “right on” or being too loose or too tight was not more than a 1/4 to 1/2 of a turn on the adjusting turnbuckle. Charlie and I had a blast getting it right, but once we figured it out, the satisfaction made the effort justifiable. The extension worked with the customary 51-52 turns to get the green lights on the panel, and the gear down and locked. After reading your advice about setting the tension between 90-100 pounds, I got curious and went out to the airport to measure mine. It was exactly 95 pounds. Good call on your part. About the only other thing I remember doing was checking to see that the gear cable didn’t rub excessively on the wing ribs in the wheel wells. Minor adjustments corrected that problem, and I was sure to polish the opening in the rib with a small Dremel stone to avoid any unnecessary wear on the cable. Well, it’s clear here today, so I’m going to go out and warm of the oil with a flight around the valley. Oregon gets so few beautiful days in the winter, but when they come, they’re usually spectacular. Keep up the good advice, we all depend on it. Thanks, Don T.
LEAKING HYDRAULIC FLUID RESERVOIR…(030102)
Subj: Emergency Pulldown
From: Brian Silcox (briansilcox@harbornet.com)
Hi Monty,
I am doing my annual on N46GS, had a strange thing happen when I pulled the gear down with the cable this time. I have been doing this each year since I got the plane ten years ago, and never had this: As the second (left) gear is reaching the stop limit, the reservoir over fills and squirts several ounces of hydraulic fluid out the cap vent. Thinking it was a transient anomaly, I reset the cable, refilled the reservoir and recycled the gear up and down…. no problems. fluid level remained at the proper level. I once again pulled the gear down manually (cap off, cowl open) and watched the gusher a second time. I repeated the above one more time to ensure I wasn’t seeing things, and once again same! It works fine in both the normal, hydraulic powered cycle, and extends fine manually. I am suspecting a port problem in the powerpack… return fluid is moving back to the reservoir, but not vice versa through the down lines during the pulldown. When the overflow occurs, the reservoir is absolutely full, and stays that way till you activate the system hydraulically, and then it indicates the fluid loss on the stick. Ever seen this one? Thanks, Brian Silcox
Brian
Unusual? No, that is a very USUAL happening. This is the first time in 10 years that that happened? You must run very low levels of hydraulic oil in your reservoir. Ordinarily, when the gear is cranked down it is quite common to have hydraulic oil spray out the vent and over the windshield. Rather than repeat myself, go to the “Monty the Answer Man” archive and read about “Landing Gear – Emergency Extension”. I think Charlie Nelson even talked about that same thing in this months newsletter. Jim
MANUAL LANDING GEAR EXTENSION…
Subj: Swift gear cable question
From: Larry Owen <Larry.Owen@Tenethealth.com>
Hi Monty
A few years ago, the gear cable was replaced during annual because “it needed it” by a inspector I never used before or since. I was doing some prep work for an upcoming annual and found something “odd”, that I have not noticed before. On the ground, the emergency retract cables are “just short of slack”, or VERY light tension. The retract spring is all the way up and lose enough to move around with your fingers. When I do a retract test (on jack stands) and retract the wheels using the hydraulics, the tension on the cable is serious, VERY serious. The retract spring is compressed all the way down and the cable will pluck like a violin string !!! I can easily adjust the cable tension, using the cable splice turnbuckle in the left wheel well, but I am concerned that by doing that, I will put too much slack in the system during wheels down. Does the retract spring need replacing to keep the wheels down tension “normal” after backing off the cable turnbuckle? The pulleys all test good, free and smooth turning. Thanks ! Larry Owen N78287
Larry
I don’t think you have a problem. The cable is “almost slack” when the gear is down. The cable is very tight after cranking the gear down. Also, with the gear up the cable gets very tight. If you read S/B #28 you will see they call for 90 – 100 lbs. I presume you have done retract and emergency extension checks at annual inspection. DON’T back off the cable tension because it “feels” too tight! — Jim
PORTER HAS A SENIOR MOMENT… (OCT 02)
Subj: SB 28
From: Porter Houston <porter.houston@comcast.net>
Monty,
Ref: Emergency gear extension. I seem to remember, or maybe I’m having one of those senior moments, but is there a special lower casting used on some late model Swifts that does not use the spacer per SB#28. Fact or Fiction? I’ve never seen anything in print about this. — Porter
Porter
Yes, s/n 3501 to 3760 had a different casting which does not require the spacer. The s/b requires some interpretation to deduce this – since it is not required to have the spacer on s/n 3501 and later, the casting is different. However, the parts catalogue only shows one p/n — 11-532-2894. When I used to have all the Swift parts around, I remember comparing two brackets and they were a little over 1/4″ different in height. — Jim
OOPS… (JAN 03)
Subj: Gear emergency pull down cable
From: John Ewing <jonewing@bellsouth.net>
Jim:
I broke my pull down cable the old fashioned way, by raising the gear with the system wound down after maintenance testing. Is it difficult to thread a new cable in? I can easily remove the sheave bolts in the gear wells, but how do you thread the male threaded end around the pulleys in the crank down apparatus itself. I say this not yet having removed the panel to look at the piece itself, but only looking at the drawings provided in normal swift manuals. Please advise if the are any “swift secrets”. Thanks for your help, hope to see you at “Sun n’ Fun. Over, Jon Ewing
Jon
I haven’t installed that cable in a few years but I don’t recall anything very hard about it. The right side (long) cable must be routed thru the three pulleys at the c/l of the airplane. To hold the screw at the outboard end of the cable at the actuator clamp a short Phillips bit in a small vice grip and then ratchet the 10-32 nut off. (unless someone has put in a slotted screw!) I don’t remember if it is necessary to remove the pulleys or not but it was not a hard job as I recall. — Jim
SHARING A “GOTCHA”… (AUG 03)
By Larry Owen
Was doing a retract test this last weekend. Things were normal enough, but was not quite smooth. Cleaned everything and did several more tests. Couldn’t find a problem but….. Did a manual test with the hand crank, worked but not well, not smooth, something as “almost” not working. Took the rest of the day to find it. In the left wheel well is the splice joining the two gear cables together. It of course, has safety wire on it. The safety wire was no longer “perfectly wrapped”. Tight and solid but not neat and uniform. It had been dragging on the Phenolic block used as a guide in the wheel well. The block was slightly beat up, the safety wire was “not straight and pretty”. A chicken or egg type of question of which problem came first. Removed the cable, cleaned and smoothed out the block, re-installed the cable and redid the safety wire, (verrrrryyyy carefully) ! Manual crank down is much smoother, electric pump sound is much more even. Have to remember to look at the safety wire separately and not just look at the gear wire during pre-flight. ( And I didn’t even have to break anything to learn something this time!)
Larry Owen
N78287
El Paso, Texas
915-577-6832
Larry.Owen@tenethealth.com
CABLE CONCERN… (FEB 04)
Subj: Pull down cable problem
From: Harry Fenton <gippsaero@charter.net>
Hi Jim,
On pre-flight today I found that the pull down cable has jumped out of both of the big cable guide at the actuator and has gotten wedged between the guide and actuator. It looks like a relatively simple fix of fishing the cable out and re-installing in the guide. Must have happened on the last flight as I check for this condition before every flight thanks to Mark Holliday’s instruction. My question- is this a common experience and is their a fix or maintenance that I should do to keep this from happening? To be honest, the cable is wedged in pretty tight and if I were out on a wind swept ramp, this could be a real hassle. I’d just like to avoid this as a continuing problem. Otherwise, the Swift is flying great! The Hanlon Wilson mufflers really put out the heat!! Too bad they don’t sound as good as the straight stacks.I should have checked first, but found some answers out on the Swift website in the answer archive. Sounds like this is a common problem. I’ve been going through each system, bit by bit, but my shop isn’t heated, so kind of tough to do any real maintenance in the winter. And when the weather gets warm, I want to go flying! It’s a vicious circle, but safety first. I’ll knock my bird down for a month or so when it gets warm and really go through it. Harry
Harry
You have already found the answer but be sure you read the Commings Hydraulic Manual Pg. “Hints and Tips From Here and There” Also I believe the blue book covers it. Like Mr Commings says — you can drill #60 holes in the crank down pulley and safety wire the cable to the groove. Univair used to sell a kit which did essentially the same thing in a more elaborate manner — it kept the cable in the groove. — Jim
CABLE CONCERN. THE PLOT THICKENS…(FEB 04)
Subj: Pull down cable problem
From: Harry Fenton <gippsaero@charter.net>
Hi Jim,
Well, what seemed like a simple fix has become a bit more complicated. The right cable is back in place, but the left is firmly wedged between the cable guide and the shaft extending from the actuator. I’ve tried wiggling the pulley to get the cable loose, but no luck, the cable is pinched really tight. It looks like I could loosen the bolt at the scissor link to which a support bracket from the cable guide attaches to get some freeplay . My concern is the down lock and if I can trip it loose with my fiddling. I don’t have a set of jacks yet, so I’m trying to do this work without. Is it a bad idea to be trying to fix this without putting it on jacks? — Harry
Harry
You usually can insert a screwdriver and pry the pulley enough to get the cable out. You will need jacks or jackstands sooner or later. If you don’t want to pop for jacks right now just make some fixed height jackstands. Make them out of car jackstands or 2×4’s just about 2″ higher than the distance from the jack points to the floor with the struts fully extended. Raise the tail, put the jackstands in place and lower the tail. (You will need a helper to put some weight on the tail) If you do get it jacked up by some means, take a big straight screwdriver and push the downlock in and partially fold the gear. It may be necessary to put the selector in the cockpit “up” or in an intermediate position. The cable will not be too tight and by manipulating it you should be able to break it free. On jacks, you can remove the center bolt in the retract linkage and then the pulley will be loose on the retract arm. The cable should come free easier then. When up on jacks, the gear should be checked per the reoccurring AD notes and the gear door fit should be checked. — Jim p.s. You can do this with just one side jacked up. That way the airplane will not have such a tendency to nose over.
WHAT A JOB! (FEB 04)
Subj: Emergency gear fixed- finally!!
From: gippsaero@charter.net (Harry Fenton)
Hi Jim,
I finally fixed my jumped cables- what a job! The cable for the left gear had developed a small loop, and then this loop was wedged between the landing gear housing and the cable guide. I had to disassemble a bunch of components to loosen the cable guide, disconnect the cable anchor end from the guide and pulled on it like crazy until it came loose. It probably took me four solid hours to get it finally worked loose. One significant condition that I have noted is that the emergency cable is pretty loose in tension. I have read in some of the discussion on this topic that the cable tension should be pretty tight. A second observation is that there is an adjusting turnbuckle that is positioned right in the middle of the grommet in the center rib in the left wheel well. This turnbuckle seems to be hanging up on the grommet as the cable pulls through. Finally, the kink in the cable caused by the pinch bent the cable and the cable tends to keep jumping out of the guide. I’m going to tension and lube the cable, and drill the guide to install safety wire as described in the Swift maintenance tips book. A final mod is to replace the Phillips screw that anchored the cable with an Allen head machine screw. The Allen head is much easier to work with than a Phillips in that tight environment. — Harry
Harry
I use the Phillips head screw, I clamp a Phillips bit in a small vice grip and that works fine for loosening/tightening. The cable tension is only meaningful after the gear is cranked down. (about 100 lbs) Normally, there is only spring tension on the cable. The cable tension should be just enough to pull the gear to the down position. Too much and you may have retraction problems or the gear may come unlocked in flight. You are on your way to becoming an expert! — Jim