Introduction: Changing Aircraft Landing Gear and Tires
Hello to my subscribers, new readers, and aviation and restoration lovers. My name is Greg, this is my third instructable.
I have worked as a float pilot, flight instructor, and aircraft salvager. I love planes, motorcycles, and electronic goodies.
Today we're going to overhaul the landing gear on a Super Cub. The Super Cub was originally a piper cub with a big engine, now it is a whole genre of aircraft designed for 2 people and with versatile engine and landing gear options.
The super cub we got in our shop was crashed due to a miscommunication regarding fuelling the plane. Everyone survived the accident, but the plane will need significant work to get flying again.
If you've ever wanted to install big wheels on your plane , or heavy duty landing gear, get out your note pad and we'll get started.
Step 1: The Old Gear / the New Gear
So you had a bad landing. These things happen, as long as you walked away, life is good.
Now what to do about the many bent parts on your airplane...
Well let's look at the old landing gear.
The impact forces caused these flimsy tubes to split ,bend, and crack.
Let's take those off and put them aside.
Now this new landing gear is a little more sturdy, painted to match the plane, and the new tires are oversize at 8.50 inch as opposed to the normal 6.00 inch tires. I put my shoe in there for scale, a normal tire is slightly bigger than my foot.
These are not tundra tires, but they are bush wheels.
Step 2: Preparing the Wheels
These wheels we got a hold of were used, so who knows the condition.
One way to find out.
We start by giving the hubs a little clean up with varsol and the trusty tooth brush.
Now that we can see what we're working with, it seems there is rusty goop around the bearings so we'll pull them apart and clean and repack.
Next we're going to look at the bearings and see if they need replacing.
Step 3: Bearings (top)
There is a little c clip which retains the bearings in the wheel hub. There is one on each side. So we'll pull out the top...
Step 4: Clean the Bearing
No surprises here, everything is grimy but functional.
Let's give all the parts a once through the varsol, then blow them dry with the air hose.
Make sure the bearing and the felt guard especially are completely dry before continuing. Any moisture sealed into the wheel hub will cause them to rust out.
You can see in the pic where I have press dried the felt guard before blow drying it and the bearing .
Step 5: Repack Bearing
I'm sorry I didn't have my shop assistant here today, she's a very busy lady.
I didn't have enough hands to properly show how to repack grease into wheel bearings, so if you haven't done it before you probably want to get a pro to show you. I like to use gloves cause this stuff get's all over.
It's not any different from other bearings though, what I do is get a lump of bearing grease in my hand and then push the bearing sides down on it with a scooping motion and pushing the grease in gaps with palm of my hand.
When the grease oozes out the other side of the bearing you're done.
Step 6: Reinstall Bearing
After cleaning in and around the centre of the wheel hub, we can reinstall the bearing in the opposite order we pulled everything out.
Remember the c clip to retain it all.
Step 7: Opposite Bearing
Flip the wheel over and do the same thing on the other side.
Clean up the hub, remove c clip, remove bearing, clean all, repack bearing, reinstall.
Step 8: Waiting for the Other Shoe to Drop...
Same procedure steps 2-7 for the other main wheel we are working with.
Step 9: Mounting the Wheels on the Gear
Now that our wheels are ready to go, we try to mount them on the landing gear axles. If you choose to put the gear on the plane and then mount the wheels that's fair enough.
Only in our case, the wheels won't slide onto the axles because they are painted. Curious. We sand off all the paint using wire wheel and then wrapping sandpaper around and getting mostly all of it off, then the wheels fit on. With a little lube and a rubber mallet, we're in business.
One large nut and cotter pin hold the wheels onto the axles.
Step 10: Mount Gear on the Aircraft
In this case, we didn't mount the gear yet, but I'll update with pictures when we do, this particular plane will need much more work before it flies again.
I have included a comparison pic of old gear vs. new gear though of a similar plane.
The gear is held on by two bolts (one for each arm of the landing gear) and a shock chord system which is like bungee suspension. Make sure you put the gear on facing the right direction. One of the landing gear arms is a little beefier and is perpendicular to the body of the plane. This one is the front. The other arm is slimmer and connects around the rear door post.
Step 11: Go Flying!
The landing gear is good to go on this airplane until the next inspection is due.
Thank you! Please raise your hand with comments and questions.
WARNING:
Do not attempt maintenance of an aircraft unless the work in questions is by definition "elementary maintenance" and you are the owner or are supervised by the owner of the aircraft. Do not attempt maintenance other than maintenance that is elementary unless the aircraft is registered as an "Owner maintenance" aircraft and the previous conditions apply, or the aircraft is a kit, homebuilt, or experimental aircraft where modification and maintenance is allowed by law in your country/state/province.
WARNING:
Do not go flying unless qualified under the licensing standards of your country/state/province. Do not fly in an aircraft unless it is properly maintained accord to the manufacturers standards. Do not fly an aircraft unless you are trained on the type and class of aircraft you intend to fly. Do not fly an aircraft unless you are current on that type of aircraft. Do not fly an aircraft without considering weather or airport conditions at your departure point, arrival point, and enroute points. Do not fly an aircraft in conditions it is not made to withstand.
8 Comments
10 years ago on Introduction
Now all I need is an airplane!?!
Reply 10 years ago on Introduction
Haha, well not exactly, but the plane is the big part.
10 years ago on Introduction
I have NO aircraft experience...but I just had to stop and check this out! I mean how often do we see aircraft maintainance and repair on here? Beside, never knopw, i might need this info one day! Thanks GC!
Reply 10 years ago on Introduction
Thanks for your comments! Sorry about the late reply.
message me anytime for aircraft info.
10 years ago on Introduction
We'd use the jack on low winged airplanes like our Cherokee 180, but with the Cessnas and other (light) high-winged craft, we'd sometimes just have a co-worker put some weight on the opposing wing while we pulled the wheel and slipped a jackstand with a cupped head under the end of the gear strut. The front wheel on a tri-gear plane is easiest, a few weight bags on the tail and you're good.
Also, to add to the above, a common problem with inexperienced folks changing tires and tubes (hey, we all have to start sometime) is pinching the tube between the wheel halves. Talc the tube, and be very careful when joining the wheel back together.
10 years ago on Introduction
I was hoping you would say something about how you jacked the plane up to remove the landing gear. I know there are special jacks that push against a dimpled jackpoint in each wing. I was curious because I have a friend with a Piper Cherokee (low wing). He got tired of paying $100 to have a tire changed. He also had a 5 ton hydraulic bottle jack. I designed and built a mount for his jack that used telescoping pipe and 1/2 inch bolts inserted in holes through the pipes to lock the telescoping section so the jack can be reset to lift to the next hole set for the bolts to lock the telescoping sections in place again. It worked and he has had to use it at least once. I did it as a favor to him for taking me with him in his plane and teaching me a bit about flying the plane.
Reply 10 years ago on Introduction
Thank you for your comment.
For this aircraft we brought it in on a flatbed and we used winch straps from the rafters in the barn to lift it up off the flatbed. It was hanging there for a week then we built temporary gear until it is ready to be put together.
I can picture the telescoping tubing you are describing. I don't have anyone handy to ask about a low wing plane, but your device would work providing you use a pad to not scratch the paint, always work on a firm flat surface, and only jack up the wing from under the wing spar. Anytime you jack up one area of the plane the C of G will cause the plane to tilt and wobble so you'd need to support the nose (or tail) all the while you are raising the mains up off the ground.
You still fly at all?
Reply 10 years ago on Introduction
Thank you for the explanation of how you lifted the airplane.
I am glad you can picture my attachment for my friend's jack. There were two tubes welded vertically to a base with the jack between them. An assembly with two slightly smaller tubes telescoped inside the tubes on the base. A piece crossed between the second set of smaller tubes with another vertical tube directly over the jack piston. I made a couple of tubes different lengths to fit inside the tube over the jack piston and each of these could be locked into position with a bolt in crosswise holes.
The airplane has a steel cone under each wing at an approved jack point. The top end of my tube over the jack piston had a heavy piece of steel over it that I had ground out to have a hollow spot for the cone to fit loosely. Anyway, it worked fairly well. The jack was always working on a factory approved jack point, never any old place that looked convenient. I also made a bar about 4 feet long with a loop welded to it for connecting a small block and tackle. He weighted the bar with sandbags and connected the block and tackle to a loop under the tail. With it he could pull the tail down to raise the nosewheel off of the ground.
I never went to ground school, nor did I try to get my license. I may have had the money, but not the time or the need. He enjoyed taking me or others with him at times. I decided I wanted to learn enough that I could get us safely onto the ground at an airport if he suddenly and unexpectedly took a long nap. Other than that, I practiced flying the pattern around a nearby airport on my Microsoft home computer simulator. I have also retired and moved to another state where I know no one with an airplane. My flying now is on commercial airliners.