Cobra27 From Slovenia, joined May 2001, 1001 posts, RR: 0 Posted (6 years 1 month 4 weeks 9 hours ago) and read 4953 times:
How much do they cost? The 747 Michelin tire I think is around 4500 $?
How many landings do they last an average? 150?
Do they blowout regulary? Are they changed frequently? How do they fill them with nitrogen
I would say around 500 landings, about every 4 months for a short haul aircraft.
With modern radial ply tyres, about 99pc are changed because they are worn out, They are extremly resistant to cuts and other damage.
Older cross ply tyres are more susceptible to punctures but only a little, maybe 97pc are changed due worn out.
I have worked on the line on A320 since 1988, and have NEVER changed a tyre for damage.
When I worked on B737-400 with cross plies, I changed about one a year for a puncture (4 flights a day).
RoseFlyer From United States of America, joined Feb 2004, 9174 posts, RR: 52 Reply 7, posted (6 years 1 month 3 weeks 6 days 23 hours ago) and read 4812 times:
Most tires are not actually new on an airplane unlike cars. Tires can be retreaded many times. You get new tires out of the factory, but after that unless there is a problem with the tire, it will be reused.
Quoting TristarSteve (Reply 3): When I worked on B737-400 with cross plies, I changed about one a year for a puncture (4 flights a day).
Finally the 737 will be moving to radial tires within the next year or so. It's been a long time in development to switch them, but hopefully it will help.
If you have never designed an airplane part before, let the real designers do the work!
KELPkid From United States of America, joined Nov 2005, 6153 posts, RR: 4 Reply 10, posted (6 years 1 month 3 weeks 6 days 21 hours ago) and read 4783 times:
Quoting 474218 (Reply 8): Its called a Schader Valve. The are also used on the landing gear for air charges.
I remember one time, when stranded at a remote airfield (due to a nose strut that had deflated on the ramp overnight) in New Mexico, trying to inflate the nose strut in a Cessna 172 with a nitrogen bottle (note: I'm not a mechanic ). Well, I ended up getting sprayed with pink, oily-smelling goo So I ran into town from the airport, and got ahold of the plane's mechanic (via payphone) back at the home base who told me "Have someone hold the tail down next time, you idiot!" BTW, it's just a standard Schrader valve on top of the nose strut...
Celebrating the birth of KELPkidJR on August 5, 2009 :-)
474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9 Reply 11, posted (6 years 1 month 3 weeks 6 days 20 hours ago) and read 4769 times:
Quoting A10WARTHOG (Reply 9): All the valve stems on the tires I have serviced from a ERJ-145 to a 747 are just like a valve stem on a car or truck tire.
The valve stem used on car and truck wheels is a Schrader Valve, just like the one used on aircraft tries and landing gear struts. While the aircraft my hold a little more pressure than the ones on your car, they share the same basic design. I use aircraft Schrader Valve caps (the yellow ones) on my car.
TristarSteve From Sweden, joined Nov 2005, 3856 posts, RR: 34 Reply 20, posted (6 years 1 month 3 weeks 6 days 4 hours ago) and read 4626 times:
Quoting AirframeAS (Reply 19): Ah ah! Hold on sec on that....thats not necessarly true. Certain aircraft tires can only be retreaded a certain amount of times. It all depends on the tire manufacturer and the aircraft type.
Yes allowable retreads on airline tyres are from 0 to about 10 times before the tyre is scrapped.
does the tread depth change each time? or will the tenth tread be as deep as the first?
not been in the game long, but all the wheels ive changed, i think the new ones have always been brand new, certainly had that "new" look to them anyway, you know you get those little strands of rubberon the surface?
TristarSteve From Sweden, joined Nov 2005, 3856 posts, RR: 34 Reply 22, posted (6 years 1 month 3 weeks 5 days 18 hours ago) and read 4553 times:
Quoting B78710 (Reply 21): does the tread depth change each time? or will the tenth tread be as deep as the first?
No it is the same.
Quoting B78710 (Reply 21): i think the new ones have always been brand new, certainly had that "new" look to them anyway, you know you get those little strands of rubberon the surface?
Retreaded tyres look brand new. We are not talking about regrooved tyres here. The whole cap is new. The only way to tell if a tyre is retreaded is to look at the sidewall. You can see the original tyre, and the retread, and the join. Sometimes the retread is a different manufacturer from the original.
By the way the shelf life of a retreaded tyre is 10 years from date of original tyre manufacture. Might not seem significant but on a line station we sometimes send tyres back because they are time expired!!