When to replace tires

[Richard Randolph]

In thinking ahead about the purchase of my first gyro plane, a used one, how often should tires be replaced if the gyro is always hangared. I realize going by tread wear should not be the only indicator. If a tire should blow either on takeoff or landing, the transient force might be devastating. Please speak to pilot technique if this should happen, as well as frequency (years) that tires should be changed. Thanks, Richard Randolph

 

[GyroRon]

When the tread is wore off them and they won't hold air no more!

 

[Richard Randolph]

When the tread is wore off them and they won't hold air no more!

So, the age of the tire is not an issue? Thanks Ron! Richard

 

[WaspAir]

Hangared or not, eventually the rubber degrades (from ozone, UV, Karma, whatever). On many, many aircraft the rubber rots long before the tire wears out. You can see issues developing on the sidewalls with crazing / cracking / discolorations on lots of tires around most airports. Over five years, it's worth watching closely, You might get double that, or maybe not. After 15 years, even the ground handling wheels for my Bell (after only tiny mileage, just rolling in and out of the hangar) developed nasty splits.

 

[Richard Randolph]

Thank you! The problem for me is then - “watching closely.” What does that mean in reality? I am hoping some of the readers have some personal stories to share here. Also. what should one expect if a tire is blown? Could the gyro be controlled safely without the risk of rolling over - especially in take off?

 

[GyroRon]

Most gyros have tires with tubes inside them. And really, most gyros don't really achieve very high speeds on the tires, be it taxi or takeoff and especially landings. for me, I would base my tire evaluations on just overall condition. If bald or dry rotted then why not replace them... but i wouldn't replace them just for no reason.

 

[WaspAir]

Thank you! The problem for me is then - “watching closely.” What does that mean in reality? I am hoping some of the readers have some personal stories to share here. Also. what should one expect if a tire is blown? Could the gyro be controlled safely without the risk of rolling over - especially in take off?

Check condition and pressure as part of your preflight inspection each day you go out to fly and you can notice any developing issue (with extra attention to everything for the first flight of the season if you park it for the winter, for example). Some people just take it for granted and only notice if it's obviously flat, and that's not wise.

Ron's comment about low speeds is right on. Groundspeed at touchdown in particular should be no more than a brisk walk.

 

[Aerofoam]

When tires are actually used, the flexing of the rubber massages natural oils in the latex and it makes it's way to the surface.
When they are not used, like on trailers, the outside surface of the tire dries out and starts cracking which continues deeper
until the tire fails. There is no substitute for actually working the rubber.
You can use topical solutions ("It puts the lotion on it's skin") as long as they are not petroleum based.
Rubber likes lanolin and something like 303 protectant can help with UV, but there is no substitute for rolling frequently.....

 

[MikeBoyette]

Most gyro tires dry rot before they wear out.

 

[Abid]

Rubber thing dry rot. Used or not they need to be replaced at the first signs of cracking or dry rotting or wear if they are used.
Usually 5-6 years is a safe bet to replenish rubber components.

 

[Sv.grainne]

My experience - I've replaced the mains twice and nose wheel 3 times. In less than 2 years due to tire wear. About 170 hrs on the machine now. Tire inspection is part of my preflight.

 

[Richard Randolph]

When tires are actually used, the flexing of the rubber massages natural oils in the latex and it makes it's way to the surface.
When they are not used, like on trailers, the outside surface of the tire dries out and starts cracking which continues deeper
until the tire fails. There is no substitute for actually working the rubber.
You can use topical solutions ("It puts the lotion on it's skin") as long as they are not petroleum based.
Rubber likes lanolin and something like 303 protectant can help with UV, but there is no substitute for rolling frequently.....

A point of knowledge that I never knew/ thanks!

 

[Richard Randolph]

My experience - I've replaced the mains twice and nose wheel 3 times. In less than 2 years due to tire wear. About 170 hrs on the machine now. Tire inspection is part of my preflight.

That seems high but obviously I’d reality..

 

[Richard Randolph]

Check condition and pressure as part of your preflight inspection each day you go out to fly and you can notice any developing issue (with extra attention to everything for the first flight of the season if you park it for the winter, for example). Some people just take it for granted and only notice if it's obviously flat, and that's not wise.

Ron's comment about low speeds is right on. Groundspeed at touchdown in particular should be no more than a brisk walk.

Obviously those replying have made safe decisions. No one has had a blown tire in either take off or landing.

 

[okikuma]

We might want to get a hold of zinc-oxide impregnated white paint and then paint white walls on our tires.

Wayne

 

[WaspAir]

I always thought it was just to go with the Dagmar bumper guards and the tailfins.

 

[StanFoster]

Richard: I had a tire only 3 weeks old blow out on me during the take off roll. Let me explain.

I bought a used Air Command and had been flying it awhile. On preflight I noticed the outside half of both the tires were wearing excessively. I put two new tires on and you would think.I was good to go. I had wheel pants so the excessive tire wear was much harder to notice. So, with brand new tires I glanced at them to see if they weren't squatting from low air pressure...and that was that.

Like I said, I only had 3 weeks on the tires, but I did fly a lot and the prevailing winds made it necessary to back taxi on a 3000 foot runway a lot. I was on my take off roll and it was almost ready to lift off on its own when my right tire popped and the gyro darted to the right. I immediately gave it back stick to get it airborne as I would have had a challenge not to tear my gyro up. Immediately after I had jumped the takeoff, I straightened out its flight path and leveled off to get more airspeed and resumed my climb out. I surveyed the tire and even with wheel pants on, I could see it was indeed a blown tire.

I remember thinking..."OH great....but wasn't too concerned as I land very slow all the time, not like what I witness at the fly ins I have attended. I just figured may as well enjoy my flight with a flat tire...then come in and crash later.....ha. Seriously, my only concern was why did a tire only 3 weeks old blow out?
I flew for about an hour and then flew back to the airport and instead of landing on the asphalt...I chose to land as slow in the grass just off the taxi way right in front of my hanger. The landing was a yawn event....only thing I noticed was it leaned to the flat tire side.

So...I took the tire off and noticed both the blown tire and the other tire had their tread scuffed down on the outside half. Like I said, this was a used Air Command I had just bought and replaced the tires on. 3 weeks of flying should not have worn these tires down that quick....of course!

I knew these tires must have been toed in....so with two brand new tires AGAIN....I placed a long straight edge on the tires and sighted an imaginary extension of the straight edge. I soon could tell I had cross eyed alignment. It actually measure 3.5 degrees of toe in. I adjusted the toe in by my own improvised method...and soon had parallel tracking tires. I went to push my gyro out the hanger and immediately noticed it pushed much easier! Like I said, I was new to this gyro...and didn't know what a normal push felt like.

I went on flying that Air Command 2 more years before buying an RAF2000. I never had tire wear problems again
..but I sure learned to watch for abnormal tire wear even with a brand new set of tires!

 

[rancherman]

Most gyro tires dry rot before they wear out.

very true with just about ANY tire these days... regardless of what they are installed on!
the 'plastics' they use seem to out-gas their binding agents... and a fully inflated tire will 'hide' the preliminary checking. You have to deflate the tire, let it go flat, and look at the surface where the tire is no longer 'round'.. If it's getting crispy, the cracking will appear like magic- pump it back up, and it disappears..
About the only tires I've found that are survivors, are the 26 ply aviation tires I use on wagons. say, 12x15's rated for 180kts.. Total bastard to mount, but typically outlast the machine they are mounted on. Must still be using REAL rubber in those carcasses.