The other day Wagonwrench and I were rotating the 8.50's on my 180 using the normal gear jacking method with a big tripod jack and gear clamp.

The question came up about how the hell would you change a tire in the bush without carrying a big jack and gear leg clamp on a Cessna gear leg? You only need to get the tire about an inch off the ground to pull the tire then change a tube. Without having someone fly in with a big jack, does anyone use a small, lightweight jack for a field repair? AND tried it??? For me, in my opinion, bottle jacks are too heavy to carry around.

I thought it would be simple to put a small scissor-jack under the bottom of the leg,.... until I saw how MUCH the gear moves during jacking. Every time you jack up the gear moves inward. Changes everything.

I carry a can of Fix-a-Flat as a first try. A tire tube for a bigger fix. I know its been done I am sure. I heard about a method of using a couple of 2x4's under the gear leg, then digging out the dirt around the tire to get it off, but sounds stupid if the dirt gives way since the tire is inches from the wood and gear leg.

Any tried and true ideas?

A bottle jack doesn't wigh that much. I carried one until recently when I discovered that for some reason it doesn't want to jack all the way up now. (cheap Walmart POS !) In my hangar, I now use a small floor jack.
My old Toyota pickup came with a mechanical (screw-type) jack about the same size as my hydraulic bottle jack. Something like that might be an option. Don't know if it goes high enough though.
FWIW, I carry a spare tube for my 800 mains, and a spare t/w tire & tube. Also carry my little gear-leg clamp set-up for a jack-point.Started carrying the bottle jack when I got a flat (at an airport!) with no one around to borrow anything from. Need to get something (like maybe the screw-jack mentioned above) to replace it in the kit bag.

Eric

I made a bracket to slide into the strut attach point on the scout. You dont have to lift much there to get the wheel off the ground.

It probably wouldn't work for you guys that have strut fairings. But it works slick, finding enough blocks to get that high in the field might be a challenge.

I've got visions of a U-shaped sapling boom hewn with a Gerber hatchet, positioned over the gear leg, and a micro-winch yarding upward on the jackpad.

You know, all 7 seasons of MacGyver can be watched online at cbs.com.

I carry a Cessna gear attach point and a two ton bottle jack. There's always rocks, sticks, or scrap lumber around to get things lifted high enough.

With the Cessna gear it's a two-step lift process. First lift to spread the gear leg out, let things down to re-set the jack, then lift straight up to pull the tire. I stash a spare tube, patch kit, and a couple cans of fix-a-flat. I don't trust the fix-a-flat for a main, and use the can just as a compressor to fill the tire. Nose or tailwheel flat tire is a non-event, but landing on a flat main is hard on the gear. Too easy with the fix-a-flat to have things pumped up nice, just to have it all leak out by the time you get home. I'd rather patch the problem and be sure it'll hold air.

Or, if things are really FUBAR, fill the tire with sand, and it'll hold round long enough to get one TO/landing out of it.

Gump

Splashpilot wrote:The other day Wagonwrench and I were rotating the 8.50's on my 180 using the normal gear jacking method with a big tripod jack and gear clamp.

The question came up about how the hell would you change a tire in the bush without carrying a big jack and gear leg clamp on a Cessna gear leg? You only need to get the tire about an inch off the ground to pull the tire then change a tube. Without having someone fly in with a big jack, does anyone use a small, lightweight jack for a field repair? AND tried it??? For me, in my opinion, bottle jacks are too heavy to carry around.

I thought it would be simple to put a small scissor-jack under the bottom of the leg,.... until I saw how MUCH the gear moves during jacking. Every time you jack up the gear moves inward. Changes everything.

I carry a can of Fix-a-Flat as a first try. A tire tube for a bigger fix. I know its been done I am sure. I heard about a method of using a couple of 2x4's under the gear leg, then digging out the dirt around the tire to get it off, but sounds stupid if the dirt gives way since the tire is inches from the wood and gear leg.

Any tried and true ideas?

I've been avoiding the subject, but it needs to be addressed. A scissor jack would work. As the tire moves inboard during the lift, drop it down and jack again. Doing this about three times will lift the tire without it moving inboard anymore. Practice in your hangar and you'll see what I mean.

The Skywagon has enough useful load to allow carrying a jack and adapter. My flyaway tool kit and spares weighs about 35 lbs. Gives me a warm and fuzzy having the stuff when in the boonies.

Since my adventure at the Owahee last year, I've got some experience with flat tires and a light plane. I used a 2x4 I found at the airstrip and cut it to be just slightly higher than the distance from the ground to the point where the gear leg attaches to the fuse. I used string to hold the upper end in position at the junction of the gear leg and fuselage. The other end was allowed to rest on the ground under the plane. Going out to the the strut attach points and lifting, the 2x4 swings under the gear leg and dangles until I lowered the plane onto the 2x4. Worked pretty well. The only caveat is that you have to be able to lift that wing. On my 650 pound plane it is no problem, but with a heavier plane, I'm not sure you could lift 1/2 the weight without help.

Somebody else mentioned a bottle jack. The cheapos don't weigh much, and even the wimpiest would have plenty of lifting force, but probably not enough stroke. I could see making some blocks out of cedar that would be nice and light, but sufficiently strong for lifting in two steps. These blocks could double as wheel chocks. You might think about making some kind of special lift attachment that would be added to the adjusting screw on the bottle jack that would make a secure way to attach to the gear.

Another thing to think about, no matter what you use for lifting, is that some spots are pretty soft, and the weight of the plane will sink a block or a little jack right in the ground. I had some trouble with this at Owahee. I had pulled the plane off the runway so it wouldn't be in the way for other aircraft, but this put it in a very soft, sandy area. I was luck to find some boards at the Hilton, but not every soft place will have these resources.

My final solution was to modify a surplus military folding shovel. I put a longer handle on it and drilled a hole for the support string. With the blade set for 90 degrees, the blade will support the weight with soft ground. I also sharpened one side of the blade to use as an axe, and ground teeth on the other side for sawing. While this tool is definitely a compromise compared to real tools made for the purpose, it will serve in several different emergencies.

I know my ideas won't fit you folks with larger planes, but maybe they will give you some food for thought.

tom

The cheap bottle jack that won't jack up all the way anymore is low on fluid. Usually there is a rubber plug on the side of the bottle, pull it out and re-fill the jack with automatic transmission fluid and your in business again.
Ever seen the plastic wheel looking things made to lift a trailer axle off of the ground by rolling it forward? They have a flat side are almost impossible to roll too far, maybe that could work on some of the tubular gear? For the Cessna flat spring guy's, I don't think you can beat the bottle jack and the slide on jack pad, except maybe with a mechanical type of bottle jack that was mentioned. Ford use to use those in their full size trucks in the 70's and I think they would extend at least 10 inches or so, weighed less than a hydraulic jack, didn't leak, and could lift a loaded F250.

Sure I can carry some big jack or 4x4 High Lift around, but I hate carrying extra heavy crap around if there is a lighter simpler method. I guess the main reason for my original post.

A64 I have seen those trailer plastic things, and gave it some thought also, just not sure how to place it.

Gump, do you have an adjustable wedge that you can place low on the gear leg? Otherwise you are cribbing 12-18 inches or so to place the short bottle jack under the wedge which fits 1/2 -3/4 of the way up the leg?

Any reason why you guys like a bottle jack instead of a lighter simple scissor type jack that comes with a car? They both go up and it doesn't have to lift much. On the surface it seems like a simple deal. Just jack it up. Until you hear about all the 170/180/185 guys talk about how their plane fell off the jack changing a tire with the gear wedges.

Its all very simple in the shop.

Thanks for your input.

Splashpilot wrote:Gump, do you have an adjustable wedge that you can place low on the gear leg? Otherwise you are cribbing 12-18 inches or so to place the short bottle jack under the wedge which fits 1/2 -3/4 of the way up the leg?

I use a jackpoint that I've had for years, made for the Cessna spring gear. It fits about two feet up, depending on the gear leg, and I use wood or concrete blocks to raise the jack to the proper height.

http://www.aircraftspruce.com/catalog/t ... cessna.php

I've never had a problem finding blocks or raw material on the ground to make a base for the jack. Like Manny says, the secret is to jack and release several times to get the gear flexed to where you're lifting straight up. Until you do that, the airplane won't be stable on the jack and you run the risk of dropping it on the axle.

I use a funky old bottle jack for the mains and the tail, but a screw jack works just fine too. I bet jack and jackpoint together don't weigh five pounds total.

Gump

Splashpilot wrote:A64 I have seen those trailer plastic things, and gave it some thought also, just not sure how to place it.

You're not going to roll a Cessna 180/185 with a flat tire anywhere by hand.

Gump

Interesting stuff...by the way Splashpilot, what psi do you use in the 8.50s?

GumpAir wrote:

Splashpilot wrote:A64 I have seen those trailer plastic things, and gave it some thought also, just not sure how to place it.

You're not going to roll a Cessna 180/185 with a flat tire anywhere by hand.

Gump

Ain't that what the fan up front is for?

a64pilot wrote:Ain't that what the fan up front is for?

I bet it'd work, but you still have the same problem as with using a jack. The spring gear is going to flex, and roll the lifter inward as the weight and friction comes off the wheel. When stuff slips and airplanes fall, something expensive is gonna break.

And, I'm not sure how you'd position the lifter onto a jackpoint. Someone on this site has to have one of the things so we can get a report.

Gump

I'm not saying it would work, really I'm not sure. I doubt it would hurt anything if it say slid off while being lifted. The attraction was light weight and simplicity, nothing to leak or rust etc. The manual bottle jack with a jack pad is probably the best idea. Hydraulic bottle jacks have always leaked for me and made a mess in whatever vehicle they are stored in.

Maybe that stuff Wup sells is a better plan.

a64pilot wrote:Maybe that stuff Wup sells is a better plan.

No, because the big problem is always shearing the valve stem or tearing the tube where you can't patch it, which means new tube to get home. Which in turn means you gotta have a way to jack the thing up.

Damn... Murphy's Law says with all this flat tire talk that's what's gonna happen this afternoon when I go play. Shit.

Gump

Damn... Murphy's Law says with all this flat tire talk that's what's gonna happen this afternoon when I go play. Shit.

Gump[/quote]

Gump you are funny.

So I guess the bottom line is jack it 2-3 times to get the gear to settle to a position that it no longer moves, use an adjustable wedge to bring the jack point as low as possible on the gear leg. Then hope you can find enough wood or rocks to crib the jack.

Flying Kiwi, 12-15 normally unless I load up then 20 because its a bitch to move around otherwise.

Thanks everyone for your input, I'll let you know how it works the next time I get a flat.

Just fly with hydrolic wheel skis all year. seriously if you had the traler axle cam idea that went on the ski axles would work great as long as you have ski axles.

As a safety measure once, we tied a rope to weights at the opposite wing tie down after we had jacked a citabria (I think). Anyway, it seemed to hold the jacked wheel off the ground ok, so hang weight (rocks, logs, passengers) on the opposite side??? John