Tyres are lethal.

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Tyres are lethal.

Unread post by MadMacs »

Use utmost caution when working on wheel assemblies.

https://www.theguardian.com/us-news/art ... -explosion
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Re: Tyres are lethal.

Unread post by StressMerchant »

Large tires contains a significant amount of energy

https://en.wikipedia.org/wiki/Mexicana_ ... Flight_940

I know there was a story that an Air Zimbabwe apprentice was killed by a tire in the early 1980s. Not sure how true the story was, maybe some of the old airways people remember an event?
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Re: Tyres are lethal.

Unread post by Mouser »

StressMerchant wrote: Wed Aug 28, 2024 11:57 am Large tires contains a significant amount of energy

https://en.wikipedia.org/wiki/Mexicana_ ... Flight_940

I know there was a story that an Air Zimbabwe apprentice was killed by a tire in the early 1980s. Not sure how true the story was, maybe some of the old airways people remember an event?
Sadly quite a few farm and construction workers have been killed or injured by tyres, usually bursting during inflation (or over-inflation) but the most bizarre was a tractor tyre, part filled with water for weight, ran away while being fitted and ran over the workers trying to stop it, killing him.

Inflation of big tyres, particularly with a seating ring) should be done in a cage (pardon the pun on an Avcom member).
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Re: Tyres are lethal.

Unread post by Lood »

Indeed a very serious and real safety hazard.

We do an average of 100 call outs per month, to do roadside repairs or replacement of truck tyres. With no cage available, we use an extension to keep the technician well out of harm's way, should something happen.
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Re: Tyres are lethal.

Unread post by SparkBerry »

Seeing as though this is Academy & Flight Safety, there needs to be a lesson here. I'll cut to the chase:

1.) NEVER put yourself in front of a tyre while inflating it. No ifs. No buts. No maybes.

..and, as I understand was the case here:

2.) NEVER disassemble a wheel while the tyre is inflated.

For (1.), this is just applicable to engineers on the flight line as it is to you as a young bush pilot pumping your 206's tire in Maun. You approach every propeller as if it's live, and you should treat every inflation as if the tire will burst. It is complacency that is the killer of many in this industry. We've all been complacent at some point, myself included. We see it, we learn from it, and never let it happen again.

For (2.), for every bolt that is removed or nut loosened, the pressure trying to pull the two wheel halves apart, is now divided amongst the rest of the bolts holding them together. Additionally, the pressure will no longer be evenly distributed around the wheel, and that pressure will find the new weakness, and it will tear itself apart in the process. This includes bolts that have been damaged by hard landings or being incorrect torqued. Engineers know this, and are taught this from the get-go as apprentices, but something went horribly wrong here, and it cost lives. I'm sure the investigation will uncover few Dirty Dozen lapses that led to this tragedy.

Wheels and tires are some of the most abused parts of an airframe. With every disassembly, they are inspected for damage and non-destructive testing is carried out on all commercial aircraft rims to ensure unseen cracks are picked up. The main wheel tyre of a 757 is inflated with nitrogen to 200psi. Compare that to your car, which is around 35psi. Imagine the energy stored in that wheel, and now imagine if that finds a weakness in the assembly. To prevent tire explosion on commercial aircraft as a result of overheating, fuse plugs that are designed to melt, typically if there is a brake overheat, allowing the wheel to slowly bleed off the pressure. An exploding tyre is what led to the Concorde disaster, albeit because of FOD, but the fact remains, the integrity of wheel and tire assemblies is critical to the safe operation of the aircraft and the personnel on the ground.

For us as grease monkeys, on the line, we would typically receive the wheel assembly as a unit from the wheel and brake shop, with no assembly required, and the removed assembly is shipped as unit to the shop where it will disassembled in a controlled environment. For light aircraft, the tyre and tube can be replaced in the field or hangar by disassembling the wheel with valve core removed and visible to you, and reassembled with the correct tools including a torque wrench, in accordance with the correct wheel manuals, and this is where it becomes pertinent to pilots or amateur assemblers who may find themselves doing this without a trained mechanic present. If you see a missing nut or damaged bolt on your pre-flight on the wheel, or a crack on the rim, walk away, far away, call the AMO. Don't try to fix it or tighten it by yourself, walk away. If you're in doubt, then there is no doubt, pick up the phone. A small wheel on a Cessna can be just as deadly as a large one, and it is not to be taken lightly. Also, during daily checks, remember that you cannot visually see what a tyre pressure is without a gauge, especially on dual bogeys. Kicking tyres, lighting fires is for actors, but professionals use a calibrated tyre pressure gauge.

For some reference material, I highly recommend this:

https://www.goodyearaviation.com/resour ... ecare.html

It makes for excellent reading an gives details of things you should be looking out for as the owner or operator and even a refresher for us spanners that may have forgotten some basics. For something so seemingly simple like a tyre and wheel assembly, it's a part of the aircraft that warrants careful attention to detail, and if often the part of the aircraft where the operator may well have to get involved with in terms of inspection and daily care, and it is absolutely critical to their safety and those around them that they are aware of the dangers and correct practices.
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Re: Tyres are lethal.

Unread post by dollar »

Learned something. Thanks Sparkberry. 200 psi/13,7 Bar. So this tyre is pumped up way beyond what your average air compressor can provide - typically a maximum of 8 Bar. Occasionaly an air compressor (8 Bar) lets go with devestating results - Iv'e seen one. If you are next to it you are likely dead. Now these tyres are at nearly 14 Bar! Goodyear appear to be confident that their tyres are pretty safe to handle unless they are damaged in some way. They warn about this. They also say that one should not be side on to the tyre, but rather behind the treads. So in this case it was either damaged or it was grossly overinflated?
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Re: Tyres are lethal.

Unread post by Sunbird »

The old, old, old, C210's had a split rim without bolts that was held by nuts on the outside of the 2 halves, as it is done nowadays. It had just bolts screwed into the threaded holes of the aluminum opposite halve. Since it was threads into aluminum, they wore out further with each tire change, until they pop. I had one go during take-off, luckily at rotation. It was better to be airborne, rather than to have left the runway at an tangent. Unfortunately it led to a 2 hour flight to a suitably firm and wide runway to put it down on the leftovers without further mishap.
This could be one of the reasons why newer models of aircraft tend to gain weight, as the solutions nearly always weigh more, each little bit adds up - unless your name is Elon: "the best part is no part". :D
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Re: Tyres are lethal.

Unread post by MadMacs »

SparkBerry wrote: Fri Aug 30, 2024 10:33 am Seeing as though this is Academy & Flight Safety, there needs to be a lesson here. I'll cut to the chase:

1.) NEVER put yourself in front of a tyre while inflating it. No ifs. No buts. No maybes.

..and, as I understand was the case here:

2.) NEVER disassemble a wheel while the tyre is inflated.

For (1.), this is just applicable to engineers on the flight line as it is to you as a young bush pilot pumping your 206's tire in Maun. You approach every propeller as if it's live, and you should treat every inflation as if the tire will burst. It is complacency that is the killer of many in this industry. We've all been complacent at some point, myself included. We see it, we learn from it, and never let it happen again.

For (2.), for every bolt that is removed or nut loosened, the pressure trying to pull the two wheel halves apart, is now divided amongst the rest of the bolts holding them together. Additionally, the pressure will no longer be evenly distributed around the wheel, and that pressure will find the new weakness, and it will tear itself apart in the process. This includes bolts that have been damaged by hard landings or being incorrect torqued. Engineers know this, and are taught this from the get-go as apprentices, but something went horribly wrong here, and it cost lives. I'm sure the investigation will uncover few Dirty Dozen lapses that led to this tragedy.

Wheels and tires are some of the most abused parts of an airframe. With every disassembly, they are inspected for damage and non-destructive testing is carried out on all commercial aircraft rims to ensure unseen cracks are picked up. The main wheel tyre of a 757 is inflated with nitrogen to 200psi. Compare that to your car, which is around 35psi. Imagine the energy stored in that wheel, and now imagine if that finds a weakness in the assembly. To prevent tire explosion on commercial aircraft as a result of overheating, fuse plugs that are designed to melt, typically if there is a brake overheat, allowing the wheel to slowly bleed off the pressure. An exploding tyre is what led to the Concorde disaster, albeit because of FOD, but the fact remains, the integrity of wheel and tire assemblies is critical to the safe operation of the aircraft and the personnel on the ground.

For us as grease monkeys, on the line, we would typically receive the wheel assembly as a unit from the wheel and brake shop, with no assembly required, and the removed assembly is shipped as unit to the shop where it will disassembled in a controlled environment. For light aircraft, the tyre and tube can be replaced in the field or hangar by disassembling the wheel with valve core removed and visible to you, and reassembled with the correct tools including a torque wrench, in accordance with the correct wheel manuals, and this is where it becomes pertinent to pilots or amateur assemblers who may find themselves doing this without a trained mechanic present. If you see a missing nut or damaged bolt on your pre-flight on the wheel, or a crack on the rim, walk away, far away, call the AMO. Don't try to fix it or tighten it by yourself, walk away. If you're in doubt, then there is no doubt, pick up the phone. A small wheel on a Cessna can be just as deadly as a large one, and it is not to be taken lightly. Also, during daily checks, remember that you cannot visually see what a tyre pressure is without a gauge, especially on dual bogeys. Kicking tyres, lighting fires is for actors, but professionals use a calibrated tyre pressure gauge.

For some reference material, I highly recommend this:

https://www.goodyearaviation.com/resour ... ecare.html

It makes for excellent reading an gives details of things you should be looking out for as the owner or operator and even a refresher for us spanners that may have forgotten some basics. For something so seemingly simple like a tyre and wheel assembly, it's a part of the aircraft that warrants careful attention to detail, and if often the part of the aircraft where the operator may well have to get involved with in terms of inspection and daily care, and it is absolutely critical to their safety and those around them that they are aware of the dangers and correct practices.
Wheel assemblies should never be disassembled anywhere but in an approved workshop, definitely not on the line or in the hangar hangar.

Always deflate the tyre before removal.
Never approach an over heated brake assembly/wheel from the side.
When loosening the main nut on the axle, make sure that the rim doesn't follow the nut i.e showing that the centre of the rim has cracked around the bolts holding the two rim halves together. This is a common failure on cargo trucks.





https://www.google.com/url?sa=t&source= ... sTazoW[url]
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Re: Tyres are lethal.

Unread post by Christo Kritzinger »

I can concur- very very dangerous. This is my experience.
rim1.jpg
rim2.jpg
rim3.jpg
rim4.jpg
I was fortunate to survive this one.
Stay safe.
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Re: Tyres are lethal.

Unread post by Ugly Duckling »

Eina :shock:

My cousin had his tibula and fibula smashed by the locking ring of a Bedford tyre while doing National service. He was walking through the vehicle park while someone was pumping the tyre.
He did his camps in 1 Mil where each year they did further surgery to tidy up the wounds.
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Re: Tyres are lethal.

Unread post by JCA »

It should be mandatory for all tyre/wheel workshops, Aviation or Vehicular including mobile facilities, to have tyre inflation cages. It was, in numerous tyre facilities in Rhodesia to the extent that failure to utilize the cages, resulted in instant dismissal. It's not to say that a tyre won't let go after inflation and removal from the cage, but the primary inflation is the most vulnerable period.
But how many times have videos been seen where petrol, or any other volatile substance has been used, sprayed around the rim and then ignited explosively. Mostly 'hold my beer' episodes.
The danger, even for the smaller tyres, cannot be over emphasized.
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Re: Tyres are lethal.

Unread post by SparkBerry »

From what I've seen on the Reddit threads from people close to the accident, the wheel assembly was actually in the shop when the A&Ps tried to disassemble it while still inflated. If that's true, it should have arrived in the shop already deflated, which means at least two holes in the swiss cheese model were lining up. One being that the guys on the line did not deflate the tire before sending it, and two, the shop guys did not verify that the tire was deflated. Doing just one of those steps would have averted tragedy.

These accidents involving human factors like complacency are just as relevant in the maintenance environment as they are in the cockpit. Because pilots are the face of the industry, it's often forgotten the dangers that maintenance personnel face on a daily basis, but these incidents can and do happen. Every maintainer has stories of the things they've seen or heard thats never made the news. It's a thankless job, but one that's fraught with hazards, and tragic accidents like this sometimes remind us to take a step back, reevaluate, and be reminded of those dangers.
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Re: Tyres are lethal.

Unread post by Davidc »

Watch from around 13:30, apparently neither of the guys working on the wheel were qualified A&P. One was a painter working overtime in the department.

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Re: Tyres are lethal.

Unread post by roadrunner »

ON the farm back 8n the day there was a ring insert onto rim.I was about ten years old and they inflated the tyre .Suddenly that insert flew out missing me hitting the wall behind mr.Tyres are dangerous
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Re: Tyres are lethal.

Unread post by V5 - LEO »

roadrunner wrote: Tue Oct 01, 2024 7:06 pm ON the farm back 8n the day there was a ring insert onto rim.I was about ten years old and they inflated the tyre .Suddenly that insert flew out missing me hitting the wall behind mr.Tyres are dangerous
...that ring murdered more people than Jack the Ripper.
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