Spare tires
Looking back at my job as A&P at a very big flight school, I think replacing tires was a big part of my average day. The daily Touch and Go’s really wore them out, and there were quite a few doozies sprinkled in occasionally with some serious flat-spotting. Our tire section in the parts room was quite extensive. Luckily, Cessna 172 tires were not all that hard to find back in the 90’s when the C-172 and the C-152 were still the vast majority of training airplanes on the ramp.
The old 1957 Beechcraft Travelair I flew last year, however, was a different story. These particular tires were so rare by now, the school kept one of each in the airplane at the ready just in case a student would flat-spot one. All you had to do then was to find a mechanic. It didn’t help, that the brakes on this aircraft were a little touchy as well. Of course, for me, the challenge was to “not be that student” and not have to use my A&P. Luckily, I was able to pull that off and never had to ask Roost Air for a favor…
Mike
I confirm students love landing with feets on the brakes. Especially when the tires are brand new. Thus my policy to replace tires only when they are fully worn (when I can see some threading on it, and not before).
However, sometimes, a lucky tire lives it’s life (being the nosewheel tire helps..) and the tire gently wears with grooves disappearing, but the tire is still OK (no threading).
On one day, one of the airfield constable noticed during his tour that I had a plane with a tire in such shape, and, being used to control cars, went to the conclusion that it was a safety hazard to be reported to the authority, and that I should be sued for it. A club instructor that was here and talked with the guy told me about it’s intentions, so I called the gendarmerie, and explained that a tire can have no grooves and still be OK on an airplane. Minutes after, the guy came back with a camera to take photographs, and well decided to fine us on that matter. So I called the gendarmerie again, this time sending by mail Goodyear’s instructions about aviation tires that stated that a tire is airworthy with “up to 1/8 of it’s circumference showing threading”. With the manufacturers instructions in hand, the guy finally reluctantly admitted that my tires were right, and that “he learned something about aviation today”….
This is one more reason to prefer grass runways over hard: they are so much gentler on the rubber. I remember one owner who had moved from an asphalt runway to our grass field for precisely this reason – amongst others. Had to change tyres every year before, on grass they would last several years.
As for landing with feet (sic!) on the brakes: that was a no-NO with every instructor I flew with. Touch down with one knot faster than stall, keep the nose high until it drops by itself, no need for brakes. If you have any, at all.
Funny story. I worked at a school and we had the usual suspects on the mains, but the nose tires where basically immortal. We taught good landing discipline and emphasized not using breaks unless necessary. We got some new instructors and the nose tires started showing extreme wear. I’m really not sure how they managed that.
Now I rarely use any breaks at all. Beta does the trick. I’m sure there are some very happy mechanics I don’t see very often.