It is disappointing to walk out to the hangar, anticipating a quick morning flight, and find your airplane sitting on a wheel pant ? deflated black rubber oozing out from underneath. Not quite as disappointing as that sudden feeling of deceleration when the tire blows on landing, of course, but nevertheless, it can mess up your morning! I have been flying the Val almost every day, and as a matter of fact, had checked the tire pressure just last Sunday for the first time in months. It seemed like she was getting a little harder to pull in and out of the hangar, a usual sign that the tires need air.
But when I checked, the pressures were right where I put them about five months ago, when I installed these tires (standard Van?s tires that came in the RV-3 kit ? I figured I might as well use them before they aged?). When I saw the flat, I naturally figured that it was caused by my checking the pressures the other day ? perhaps the valve not seating properly, and the safety cap gasket leaking. So I jacked things up, added air, spit-checked the valve for leaks (found no bubbles), and went on my way for a short flight to get fuel. A couple hours later, I went out to the hangar ? and once again, she was settling down on that tire! Out came the jack, and this time, the wheel came off and I disassembled it on the work bench. Fortunately, we keep spare tubes on hand(Michelin AirStops), so it didn?t take long to put it all back together. (What took the time was that it was evident from ear patterns that it was time to flip the tires on the rim anyway ? which meant I had to do the OTHER tire as well. And, oh well, three years on the brake pads ? I finally got through the wear notch, so it was time to change those too?.)
Once I had the airplane airworthy, I inflated the bad tube, and checked for leaks, and this is what I found:
It?s a small line of nicks on the shoulder of the tube ? about where the tread meets the sidewall. Only the largest was making bubbles, but it looks like something linear caused the damage. As normal, I inspected the inside of the tire by running my ginger tips around, feeling for anything that might cause a puncture, and didn?t find anything. I DO re-use tubes (after inspecting them) a few times, so it is possible this started with a previous tire. I?ll probably never know ? just found it interesting. A good reason to do a thorough inspection every time the tires, tubes, and wheels are apart!
Paul
But when I checked, the pressures were right where I put them about five months ago, when I installed these tires (standard Van?s tires that came in the RV-3 kit ? I figured I might as well use them before they aged?). When I saw the flat, I naturally figured that it was caused by my checking the pressures the other day ? perhaps the valve not seating properly, and the safety cap gasket leaking. So I jacked things up, added air, spit-checked the valve for leaks (found no bubbles), and went on my way for a short flight to get fuel. A couple hours later, I went out to the hangar ? and once again, she was settling down on that tire! Out came the jack, and this time, the wheel came off and I disassembled it on the work bench. Fortunately, we keep spare tubes on hand(Michelin AirStops), so it didn?t take long to put it all back together. (What took the time was that it was evident from ear patterns that it was time to flip the tires on the rim anyway ? which meant I had to do the OTHER tire as well. And, oh well, three years on the brake pads ? I finally got through the wear notch, so it was time to change those too?.)
Once I had the airplane airworthy, I inflated the bad tube, and checked for leaks, and this is what I found:
It?s a small line of nicks on the shoulder of the tube ? about where the tread meets the sidewall. Only the largest was making bubbles, but it looks like something linear caused the damage. As normal, I inspected the inside of the tire by running my ginger tips around, feeling for anything that might cause a puncture, and didn?t find anything. I DO re-use tubes (after inspecting them) a few times, so it is possible this started with a previous tire. I?ll probably never know ? just found it interesting. A good reason to do a thorough inspection every time the tires, tubes, and wheels are apart!
Paul
