Here is a heads up about wheels to all of us that fly older aircraft.

A friend of mine who is very serious about maintenance had this happen recently. The aircraft is used for personal transportation and back country camping. The co-pilot main gear wheel broke apart during a normal landing on a paved airstrip. It was the inner half of the wheel.

Things got very busy when the tire expanded at the wheel separation. The 800x6 tire (it had 25# air pressure) expanded far enough to grab the brake caliper which cut through the tire and tube and almost resulted in a ground loop. The caliper bolts were bent which moved the brake lining plate and shim into the brake disc assy. The disc, brake lining plate and shim were were damaged beyond repair.

Here are some pics of the wheel half. The missing piece was not found. Note the discoloration of the metal on the pics. It seems the wheel cracked from the inside some time in the past and then finally let go. It may have been possible to see this problem with the tire removed from the wheel but the owner had replaced the tires within the past 6 months and did not see any evidence of this problem when the tires were changed.

And I thought I was unique.

Back in 2006, taking off from a paved strip, with a slight right cross-wind, I just lift the tail up in my C170B, and roll up onto the right main and all the sudden things get VERY strange. I don't know what happened, but I opted to abort the takeoff and see what has happened. Reduce power, tail down, elevator in my lap, touch the brakes and WHAM, the fastest 180 degree left turn you can imagine into the grass and gravel. Body unharmed, prop tips bent, right wing tip bent up, shut down the engine, say "SH**T", shut off the fuel and the master and look for cause. All of this took about three seconds.

Much to my suprise, my 8.00 x 6.00 tire is out on the runway, as is my tube, and the outboard bead of my Cleveland wheel is in six pieces, all curled like little twisted pieces of magnesium. I learned that the rubber on the left side is better at braking than the remaining metal hub on the right side. I had tons of remaining runway, and I should not have touched the brakes. Hindsight is 20/20.

The wheel looked fine at annual, and during preflight. All of the pieces showed significant internal corrosion (intergranular, according to a metalurgist). There were some shiny sections that showed it had been working up to the big suprise, but nothing visible from the outside.

The wheel tag indicated that it was maunfactured on 12-72 (December of 1972).

Good news was I had paid my premiums to Avemco, bad news was I had a $5k deductible. Funny thing was, they would only pay to replace the right wheel. Guess what, I opted to pay for the left one.

Kinda wished I had installed the new Clevelands BEFORE the failure.

Also, I have one used Cleveland wheel for sale, manufactured 12-72. Sorry, sick humor.

My main wheels show moderate damage on the inside where some previous owner or mechanic had incorrectly used a pry bar to break the bead on the tire. It's a good hidden place for corrosion or cracking to start.

Wheels are something that owners of certified airplanes can take apart and inspect. If you've never had your wheels apart, it might be worth taking a look. Also, most planes use a springy landing gear, and when you operate them at less than gross weight, the gear legs aren't fully spread, and so you get more wear on the outside edge of your tire. While the wheels are apart, it's trivial to flip the tires around so that the inside edge becomes the outside edge, thereby prolonging tire life. And, it's a good opportunity to grease the wheel bearings.

Also, if you've got hollow axles, you might be surprised at what you will find in there as well, although that's probably a story for the campfire!

Had a 206 (s/n 18) do that years ago. He had a full load of Russian farmers that were visiting, and as he turned to do a runup into the wind, the r/h main wheel broke, just like yours. Locked up the brake and I had to jack it up on the spot and switch wheels with the 185 to get it back to the hangar.
I've talked to a few others that had the same thing happen.
John

Thanks for the reminder I went to the Caveman Ranch Fly in and Saturday landed at 6 dirt fields and hammered the shit out out my 6" 3 bolt Cleveland's I looked at the gear boxes after I got back but forgot to look at the wheels.

Another thing that'll lock up a wheel is having a nut come off the bolt on the wheel halves. This will allow the bolt to back out, and jam up against the gear leg/brake assembly and stop the wheel from turning. Some guys, I don't, put the nut facing in when putting the wheel halves together to prevent this. Though it does make it hard to see the nut on preflight.

Gump