Tire pressure

[Gerald McKibben]

All the inspection guides I've seen recommend 20 psi for the tires (all 6" I presume). I've been using 32 psi because the plane rolls so much easier. I have to pull uphill a bit to get out of the hangar.

I don't notice any problems in the higher-than-recommended pressure. I don't like to do wheel landings; maybe that's the reason. I'm sure it would a little less bouncy with lower pressures.

[Hank Jarrett]

Re: Tire pressure

Over pressure on tires is not a good idea. They will roll easier, but part of the shock absorption in a Taylorcraft is from the tire flexing on landing. By over inflating the tires you are transmitting those loads to the bungees and the landing gear to fuselage bushings. When you change your bungees you will be able to see how much you may be beating up those bushings. Under load it is VERY hard to tell when the bushings are damaged.
If you grease in every landing you "may" be all right, but I don't know anyone who does that, no matter what they tell others. At 32PSI you are at 160% of the rated pressure.

Hank

[Gerald McKibben]

Re: Tire pressure

No I don't grease in every landing, for sure. I will let out air to 20psi.

[astjp2]

Re: Tire pressure

The terrain you are landing on will determine what your tire pressure is. I run 8-12 on turf or gravel, 20 on asphalt. I like around 30 in the tail wheel but the critical thing is the tie bolts, if you run too much pressure, you can break the bolts and the only thing that will hold the wheel halves together is the axle nut. This is why you must always deflate the tire before removing the wheel, if the tie bolts are broke, the wheel could blow up in your face. Tim

[Hank Jarrett]

Re: Tire pressure

We had that happen on an A-6 or F-14 tire once (hard for me to tell after it blew and I wasn't on the investigation). It was a MASSIVE explosion and only the tire cage saved the guys life. Turned out there was a new guy in the tire shop who hadn't been trained and was told top go put the valve stem flags on the tires. There were little flags with the wire going through a valve stem cap. If the valve core wasn't removed, you couldn't put the flag on because of the wire. That makes sure the tire is deflated before the bolts are loosened.

New guy didn't understand the logic behind the process, but the chief told him to put the flags on the tires, so (can you see it coming?)....he cut the wires off because the valve cores were in the way, and OBVIOUSLY someone hadn't "trimmed" the flags yet.

As the tire mechanic started removing the bolts the tire jumped (not sure how many bolts were loose at the time) and he dropped the air wrench, dove out the cage door as the tire blew up. The wheel half hit the cage and the mechanic was blown about 30' across the hangar deck. He was beat up, deaf, semi-conscious, but alive. The steel tire cage looked like something from a Road-Runner cartoon. I think every guy on the hangar deck had ringing ears and I was two decks below and thought it was a 500# bomb going off. At least it was a short GQ that was called off as soon as the Hangar Deck Control watch told the Bridge it was NOT an explosive that went off and there was no fire.

EVERY ONE on the ship got some training on tire safety after that and the tire shop was taught to NEVER trust the flags any more. Don't think just because our tires are small they aren't dangerous. Where an A-6 tire was like a 500# bomb, ours are still like a good size grenade. If the bolts fail and you get hit by a chunk of the wheel, you will be just as dead.

Hank

[Bravo 6]

Re: Tire pressure

The structural aspects/impacts that Hank outlines makes complete sense and bears compliance in my mind. To add to that, I had someone 'helping' me and they put in about 30 lbs of pressure in my tires (6.00). I was operating off of an asphalt runway and noticed very undesirable handling characteristics. It just didn't feel right. 20 lbs feels and seams to work much better!

[astjp2]

Re: Tire pressure

What is your wheel alignment? Sounds like your toe alignment is off if a change in tire pressure is causing undesireable taxi handling. Most people squirm when they see me take a big pipe and tweek on the gear to get it to 1/8" toe and equal to the centerline of the airplane. If its toe out, it will dart all over as weight shifting is applied side to side when you taxi..Tim

The structural aspects/impacts that Hank outlines makes complete sense and bears compliance in my mind. To add to that, I had someone 'helping' me and they put in about 30 lbs of pressure in my tires (6.00). I was operating off of an asphalt runway and noticed very undesirable handling characteristics. It just didn't feel right. 20 lbs feels and seams to work much better!

[swoeric]

Re: Tire pressure

i run 7 ish

[astjp2]

Re: Tire pressure

Good way to shear off a valve stem, been there done that at 8psi.

i run 7 ish

[cvavon]

Re: Tire pressure

I run 4 psi in 26" in alaska bush wheel tires

[astjp2]

Re: Tire pressure

Their valve stem in on the tire, not through the rim so not really an issue.

I run 4 psi in 26" in alaska bush wheel tires

[taylorcraftbc65]

Re: Tire pressure

OK, I have a question, guys, my 4,700 foot strip is a hunk of far west Texas grassland that was mowed with a garden tractor regularly ever since it was graded 9 years ago. It feels a little rough, as you go over the grass clumps. My good friend, knowing how I fly, gave me his 8.00's from his C-175, I think. They are non retreads, but are are new tires with 80% still on them. Knowing that I only operate from pavement once every 10 or 15 times, what pressure should I run in those tires??
Brie

[cvavon]

Re: Tire pressure

Brie if i were using them i would run 12 to 15 lbs any less and they will spin on the rim and pull the stem out of the tube.also if you mow in three different directions it will help the grass clumps.

[taylorcraftbc65]

Re: Tire pressure

Thanks, I will run that in my tires. The next time that I will have to mow, will be next Spring, but I will remember.
Brie