Nitrogen tires
I just bought a 5th wheel. I have yet to take possession of it:), I notice the tires are serviced with Nitrogen. So how do I maintain nitrogen filled tires?
Forum Discussion
I've posted this on a couple of other forums. When I was at Boeing, I was in the landing gear/tires/brakes engineering group for several years. We started a project to stretch the 727, and ran afoul of a new FAA requirement that we had to certify that a tire burst on a main gear tire, after retraction, wouldn't endanger the airplane.
There had been one fatal accident with a Swissair Caravelle where a tire burst had brought down the airplane, resulting in 70 fatalities. There had also been an accident which totalled a USAF C-5A, but only minor injuries to the crew and one with a 727 where an 18" hole had been blown into the bulkhead separating the wheel-well from the pressurized aft cargo compartment. In that one, three USPS mailbags jammed in the hole and slowed the decompression rate so that there was no big structural failure. The Mexicana wreck was later than my research and shouldn't have happened. Maybe they didn't get the word, who knows?
Common to all these incidents were very hot brakes and gear retraction before they had cooled sufficiently. I did a detailed study on the 727 incident. Structural cables that made up the bead of the tire had failed in tension and there was extensive burning of the inside of the tire carcass. We eventually concluded that there had been a spontaneous explosion inside the tire, reaching a pressure of almost 12,000 psi to cause the bead failure.
It turned out that the airplane had taxied a long way at the airport because the take-off direction had been reversed because of a wind shift. One of the brakes was dragging and got very hot, particularly during the takeoff run. At the time, that particular airline was still using air for tire inflation. Boeing put out an immediate recommendation to switch to nitrogen, which cannot support combustion/explosion.
You only NEED to use nitrogen if your RV can accelerate to 150mph with a dragging brake and then you retract the wheels into a closed box. If you WANT to spend the extra money, that's up to you. Even using air at gas stations these days costs money, so I carry a small compressor to keep my RV tires at the correct pressure.
There had been one fatal accident with a Swissair Caravelle where a tire burst had brought down the airplane, resulting in 70 fatalities. There had also been an accident which totalled a USAF C-5A, but only minor injuries to the crew and one with a 727 where an 18" hole had been blown into the bulkhead separating the wheel-well from the pressurized aft cargo compartment. In that one, three USPS mailbags jammed in the hole and slowed the decompression rate so that there was no big structural failure. The Mexicana wreck was later than my research and shouldn't have happened. Maybe they didn't get the word, who knows?
Common to all these incidents were very hot brakes and gear retraction before they had cooled sufficiently. I did a detailed study on the 727 incident. Structural cables that made up the bead of the tire had failed in tension and there was extensive burning of the inside of the tire carcass. We eventually concluded that there had been a spontaneous explosion inside the tire, reaching a pressure of almost 12,000 psi to cause the bead failure.
It turned out that the airplane had taxied a long way at the airport because the take-off direction had been reversed because of a wind shift. One of the brakes was dragging and got very hot, particularly during the takeoff run. At the time, that particular airline was still using air for tire inflation. Boeing put out an immediate recommendation to switch to nitrogen, which cannot support combustion/explosion.
You only NEED to use nitrogen if your RV can accelerate to 150mph with a dragging brake and then you retract the wheels into a closed box. If you WANT to spend the extra money, that's up to you. Even using air at gas stations these days costs money, so I carry a small compressor to keep my RV tires at the correct pressure.
