5 punctures in 2 years, any ideas?

[COYB]

I'm a member of a syndicate that operates a PA38 out of Kemble, in the last 2 years we have had 5 punctures! In decades of flying (20 in this syndicate alone) I’d never encountered a flat tyre/blow out until September 2017, and now we have had 5 in 2 years: 3 starboard side and 2 port. It is beginning to be hard, though, to put this down to bad luck.

There doesn't appear to be any pattern to the flat /blow outs, the tyres themselves don't have any flat spots, which would indicate a landing with the brakes applied. The first two flats showed an absence of chalk dust, nothing else. Only one had a large pin hole in the side wall of the inner tube, no evidence of what made it. The final two were found completely flat.

Any ideas?

[A and C]

Bottom of the range budget tyres ?

I operated three aircraft on a flying club a few years back and top of the range inner tubes and mid range tyres ( condor or Michelin ) offered the most landings / £.

Goodyear flight custom offers the most landings but replacement was usually required between maintenance checks and involved higher costs

almost all punctures being attributed to failure to maintain the correct tyre pressure.

[Pilot DAR]

No chalk or talcum powder? 'Could be chafing, or a wrinkle in the tube, though if that was the cause, it should be evident upon disassembly. I've had two flats in one wheel on one of my planes in the last year, having never had a flat mainwheel before. Sometimes, tubes just have a weak spot. Also consider that the tire could have been under inflated, which can cause the tire and tube to get hot, particularly after a long taxi. PA-38 tires in particular work a little harder, as they are small for the size of the plane compared to other types. Also check to be sure that you're running the correct ply rating tire.

My idea is to maintain a spare built up wheel to replace each on my planes quickly if needed. When I took my taildragger on a long trip, I left a whole tailwheel assembly built up and ready for shipping at home, so my daughter could ship it if I needed it. That tailwheel works really hard, with an operating pressure of 70 PSI, and if flown with too low a pressure, a shimmy can develop, which in the past has broken a steering arm - so I have extra incentive to keep that wheel round!

[BigEndBob]

We have about 3-4 a year across two club aircraft.
Never anything stuck in the tyres.

[MrAverage]

What A & C said.

[Maoraigh1]

Does your aircraft visit an airfield which uses wire brushes on the runway in winter? The machine is followed by a magnetic pick up device. But wire bits can remain at edges. I found a few at the edge of the hangar apron, where I push onto the grass, this summer.

[COYB]

Thanks for your replies.

It appears our maintenance outfit have been using rubbish budget tyres and we are now going to replace the blown one with a top-of-the-range Goodyear. So fingers crossed.

We'll look into and monitor the correct tyre pressures.

There also is a concern that the plastic matting by the gnat on the grass taxi way may also be a contributory factor, we'll have to ask fellow flyers if they have also experienced issues on said matting.

[astir 8]

Also check if tyres are being fitted in clean conditions. Grit or bits of rim corrosion between tube and tyre can chafe through tubes invisibly, as can corrosion on the interior of the rim.

[scifi]

Have you checked the type of stones you have on the taxiways. Our taxiways are WW2 vintage and have lots of sea type pebbles on them, from the concrete breaking up. Maybe you have sharp Flint type stones that are sure to do some damage.. I suppose you have ruled out sabotage, if your plane is securely housed..?
.

[treadigraph]

Originally Posted by astir 8

Also check if tyres are being fitted in clean conditions. Grit or bits of rim corrosion between tube and tyre can chafe through tubes invisibly, as can corrosion on the interior of the rim.

Obviously not the case on a Tomahawk, but I had a long series of inexplicable punctures on a push bike; colleague said "check the rim tape" and sure enough a short stretch had slipped and the tubes were fretting on a spoke recess. Prior to that, every puncture I'd ever had was something through the tyre. Now when changing tubes I have a good look round the rim and give it a careful wipe with paper towel, see if anything snags.

[mikehallam]

FWIW.

If a tube type & the a/c is used at fields with Blackthorn hedges (Sloe) the hedge cuttings have vicious spikes which enter even a stout car and my tractor tyres !
Somehow despite feeling all around inside the tyre before refitting to the wheel they can still lurk and repeat thier damage to an inner tube.

[NutLoose]

Make sure the rim is cleaned of all the old rubber deposits that build up too, I put on ours Goodyears with their tubes as well, makes sure there are no rubbing or creasing in the tubes, if there is replace it, use chalk and don't forget the valves either, if reusing the tube inspect it. If it has it on it check the date of the tubes, it might sound odd but if the tube was ok it would get reused, I did one that the tube was serviceable in it, but I noticed the date on it was 1975, so decided the poor thing had served well but it was about time to retire it lol which at the time was about 35 years old!

Tryto avoid tight turning circles to that load up the tyres as well.

[memories of px]

absolutely, i punctured a pa28 nosewheel tyre doing a tight turn getting into/out of wind for the power checks, felt a bit of a wobble going down the runway, didnt think too much of it until we landed an hour later on a totally flat tyre, that woke me up!.

[A and C]

Originally Posted by memories of px

absolutely, i punctured a pa28 nosewheel tyre doing a tight turn getting into/out of wind for the power checks, felt a bit of a wobble going down the runway, didnt think too much of it until we landed an hour later on a totally flat tyre, that woke me up!.

The most likely reason that nose tyre went down was it was under inflated.

I would also say that unless you are operating in a very strong wing turning directly into wind in a PA28 is a wast of effort, the wind from any direction in front of the wings is good enough.

[Russell Gulch]

For power checks, into wind or tail to wind is OK. cross-wind is less desirable (assuming tractor rather than pusher type engine).
Russ

[Andy H]

I had a string of punctures but solved the problem after buying a new tyre pressure gauge. The old one was faulty resulting in underinflated tyres

[A and C]

Originally Posted by Russell Gulch

For power checks, into wind or tail to wind is OK. cross-wind is less desirable (assuming tractor rather than pusher type engine).
Russ

Please explain your reasoning.