tire selection

[Dot_AK]

what criteria do you look at when selecting tires for your aircraft?

What size do you choose for which planes - and what do you use those planes for?

 

[katanabob]

For a given wheel, there are any number of tires which may fit; for a given airplane, there are certain wheels and tires which were itemized within the type certificate data sheet when the aircraft was originally certificated. Any wheel/tire combination other that those specified would require a Supplementary Type Certificate (STC) to be approved and placed within the aircraft's logbooks.
As to selection of the allowed tires (or selection in general) you can buy tires in 2 to 8 (or more) ply which is essentially how many layers of rubber there are on the tread. Aircraft with higher touchdown speeds will generally require higher ply tires. (For example, most Bonanza tires are 6 ply, we use 8 ply on ours)
Some people like one brand over another. I like Michelins; they wear like iron. You can buy a Condor tire for half the cost, but in my experience it will last a quarter as long.
What kind of flying are you doing? If you're flying out of dirt and gravel strips, (or the bush) the tires you choose will be very different than if you're always operating off of 6000' paved strips.

 

[CatYaaak]

If your aircraft has only one wheel per main gear, buy the highest quality tire available (even if you think it's more than you can afford), and change them early and often. With tires you usually get what you pay for, and while all flat tires are equally flat, your biggest concern at that moment is that the flat tire remains attached to the wheel, and doesnt shred, etc as you roll down the runway trying to stop. If it comes completely unglued and leaves the airplane, damaged wheels and struts (or worse if things really get exciting) are more expensive than the money you save by scrimping on tire cost, or letting them wear to the point that they decide for you when their useful life is up. Apparently, they do this at the highest speed, at night, and on the wettest, narrowest, shortest runway possible.

I remember our Westwind tires were 18-ply, rated to 210, and cost about $700 dollars each, but that was money well-spent considering each one protected $10,000 wheel and brake assemblies, struts, flaps (if things began to grind down), and against FODing an engine. Ones who have been unfortunate to have experienced incidents of lost tires say its a lot noisier than a regular takeoff or landing (and at this time I'd like to thank the aircraft designers at Israel Aircraft Industries for deciding to rest their 23,500 lb. bird on only one tire per side, thereby making this appreciation for good rubber possible).

Of course, this doesn't even touch on the costs involved if such a loss of directional control caused a high-speed runway excursion, forcing an impromptu and eye-opening "Bagel Bomber Baja" ride through the pucket brush. Whether at 60 knots in a Skyhawk or 140 in an Israeli Love Machine, I'd rather be in my Jeep for that kind of "moment".

Of course, dual-wheel main gear tires and nosewheel tires aren't quite as critical, and you could get by with less quality if you swear to change them when there is any question as to how much life is left in them. No matter what kind of tires you buy, always make sure the wheels are inspected during changes as per maintenance manual.

 

[avbug]

A good set of retreads will run you just as long and just as well, for much less cost. I've used them to good effect on light airplanes through large heavy airplanes, without ever so much as a hint at a problem. I'm not big on their use on high speed applications on small tires, but otherwise, they're great.

Desser Tires can give you a good price and good service.

 

[katanabob]

Well put. Especially the part about the wheel inspections being important...
I was flying a dentist around in his Skymaster for a while, and one night in particular we landed at some airport in the middle of nowhere. On the rollout, I noticed the aircraft intermittantly pulling to the right, accompanied by a massive braking action. This intermittant braking action was strong enough to set up an oscillation that lifted the nose up and slammed it back into the ground about once a second. I cleared the runway and brought the aircraft to a stop just past the hold short--shortly before coming to a complete stop I heard a loud ping, much like that pin dropping on the AT&T ads.
I got out of the airplane with my flashlight and immediately noticed many shiny little things on the ground in a semi-debris field behind me. Closer inspection showed these small fragments to be the right wheel. A few large sections stayed in the tire, (they actually penetrated the tube) and most of the rest completely disintegrated.
Examination of the wheel (a magnesium wheel) revealed severe corrosion which should have been noticed perhaps when the tire was changed during the annual less than a month before. The wheel had powderized (it was even a good landing!) and thankfully I was able to maintain directional control and get off of the runway. (as planned on a taxiway and not the grass)
The rest of the night was equally interesting, though has nothing to do with tires and wheel inspections. Thus, I will save you all the pain of listening to me retell it.

 

[TurboS7]

The biggest one I can find an STC for.

 

[throttlejockey]

It really depends on the application.

For those who are operating fleets of aircraft in a high utilization environment (flight schools, air-taxi, commuters) you just cannot beat retreads for the cost. Retreads have equal strength and durability - as long as they are on the first few retreadings. We would not use retreads after R6. (R1 = first retreading, R6 = sixth retreading).

For personal light airplanes, I would go with the highest ply tire available per the aircraft maintenance manual. Usually the MM only specifies the tire size and ply requirements, and not any specific brand. Retreads are usually not worth the trouble for personal airplanes because the cost savings does not justify the trouble or the shipping costs to/from the retread shop.

I do not recommend paying the $$ to buy the STC for a specific wheel (switching from Cessna to Cleveland) unless your wheels are BER (Beyond Economic Repair) and there is no cost to obtain the STC as part of the switch.

As for different brands of tires, Goodyear and Michelins are considered the best, but with anything else, you should always consider your wallet, and the application. If you are only going to change your tires once or twice a year, it makes sense to spend a little more for better quality. If you are a fleet operator changing several sets of tires each month - you may want to consider something a little less expensive or consider retreading your tires.

throttle

 

[tarp]

Hey Dot,

A student buying aircraft tires. Did you buy the 152 or 172?

Grass fields / Soft fields, I 'll go along with what some of the others say about buying the biggest tire that will fit the rim and still be legal.

Off of tarmac, just go with the POH - I think you get a good roll-out with "right sized" tires for any plane.

I used to use 4-plys to save bucks since my students were literally ripping the treads off my two planes, but I went 6-ply for my own single. Had good luck with all the brands - Air hawks worked nice, Good Years were fine. Folks say the Michelins are nice, but they've always been too pricey for me. When I had students in planes, I never saw an old looking tire. Now that I fly my own stuff around, I have to watch for dry rot more than wear and tear.

I've never done re-treads due to my own background in cars and trucks. The old retread stuff used to be just miserable. Our airline uses retreads and they seem to work just fine.

 

[azpilot]

A good set of retreads will run you just as long and just as well, for much less cost. I've used them to good effect on light airplanes through large heavy airplanes, without ever so much as a hint at a problem. I'm not big on their use on high speed applications on small tires, but otherwise, they're great.

Desser Tires can give you a good price and good service.

I agree with Avbug. Retreads are great! I buy them from Desser as well for about $58. They come with a yellow tag which you need to put in your logbook. Last year I put and retread on one side and a Aerotrainer on the other. The Aerotrainer wore out in less than a year (250 hours) and the retread still looks new.

- AZPilot

 

[avbug]

AZ,

It will even out...just wait until you get a year of crosswinds from the other side...