Airliner tyre wear

[facthunter]

This is what you are paid for. Management these days would not have a clue.  Nev

[Deano747]

5 hours ago, Methusala said:

Landed at Hamilton last week. 737 came in so hot we hit at about 2g then bounced. Full reverse thrust, lift dumped and brakes to avoid tumbling off the end into water. As Nev says, we had a close view of the tray tables. Landing pilot probably needs an eye check.

Take it you mean Hamilton Island.

1,700m landing distance is bloody short.

737 has a little wing - high wing loading - high Vref (landing speed). Faster than the 767 and 747 for example.

Touchdown zone is ~ 300 m in for them, so ~ 1,400m max to stop in using tiny little brakes on 4 wheels.

Little wonder it was a positive arrival (no float) and then everything it had to avoid getting the passengers wet.

[facthunter]

You can't  slow down till the wheels are on the ground and the spoilers raised..  Nev

[Moneybox]

Ok so we tested your theory. How much does the stationary wheel slow the aircraft upon landing?

 

 

While on our way to Perth we were travelling at 100km/h when I noticed we were about to be overtaken by a stray wheel and tyre. I alerted Mrs M who had time to open the camera app on the iPad and take a shot.

 

 

 

Then she used the iPhone to record the rest of its journey down the Great Northern Highway. The fact is it was our trailer spare that hit the road stationary but still managed to rotate at road speed in a very short period of time. It didn't need any fan assist to get it spinning and it didn't lose too much speed in the process. It did, however, travel for a very long way so may actually assist in keeping the plane moving down the runway 😁

 

Loose wheel2.HEIC

[BrendAn]

38 minutes ago, Moneybox said:

Ok so we tested your theory. How much does the stationary wheel slow the aircraft upon landing?

 

 

While on our way to Perth we were travelling at 100km/h when I noticed we were about to be overtaken by a stray wheel and tyre. I alerted Mrs M who had time to open the camera app on the iPad and take a shot.

 

 

 

Then she used the iPhone to record the rest of its journey down the Great Northern Highway. The fact is it was our trailer spare that hit the road stationary but still managed to rotate at road speed in a very short period of time. It didn't need any fan assist to get it spinning and it didn't lose too much speed in the process. It did, however, travel for a very long way so may actually assist in keeping the plane moving down the runway 😁

 

Loose wheel2.HEIC 271.02 kB · 0 downloads

That happened to me on the way to Perth years ago. I hit a bump near Williams and the spare went rolling down the highway. Never left it loose in the trailer again.

[onetrack]

So MB, your theme song now, is that old Kenny Rogers song, "You picked a Bad Time to Leave Me, Loose Wheel!"?  😄

[onetrack]

There's some interesting measurements on landing gear loads of the XB-70 in the NASA technical report, below. Yes, the XB-70 was a huge aircraft, but the measured drag loads on the landing gear trucks at touchdown, were very substantial.

 

Pages 11 and 12 show the graphs, lbs on the left, Newtons on the right. NASA measured the landing gear loads in every direction.

 

https://ntrs.nasa.gov/api/citations/19680026601/downloads/19680026601.pdf

[facthunter]

There are ways of watching the Landing gear of a heavy as the wheels touch down. Believe me the wheels move back a long way and you never land with the brakes on. With antiskid it's not possible, anyhow.  Without antiskid Large planes would blow tires most of the time. Nev

[BrendAn]

A Jetstar flight turned back this week because it blew a tyre on takeoff.  Is there a risk of jamming the gear if they retract it or some other reason they don't fly on and change it at the destination.

Edited December 1 by BrendAn

[facthunter]

A good question.  It might have to do with runway length and  fire services at the destination or a possible wheel overheat condition where retraction is not safe.  Nev

[Deano747]

Or no engineering and/or spares wherever they were going .....

[facthunter]

THAT wouldn't stand up in court.  Nev

[facthunter]

PRIME concern is what is most SAFE in a Court of LAW.   Nev

[Deano747]

...

Edited December 1 by Deano747

[peterg]

13 hours ago, facthunter said:

PRIME concern is what is most SAFE in a Court of LAW.

Really?

[facthunter]

In Matters AVIATION, YES..  Most definitely.   You are the Master of a Vessel.   Nev

[peterg]

1 hour ago, facthunter said:

In Matters AVIATION, YES..  Most definitely.

Rather than go the way of your frenemy frequent contributor Turbothingo, you should leave the bush lawyer stuff alone - as I understand it, like him, you are unqualified, inexperienced etc etc and your comments may well mislead some members of this forum - I presume you are not keen to be labelled as one who misleads, provides incorrect or out of date information etc

 

1 hour ago, facthunter said:

AVIATION, YES..  Most definitely

 

CRIKEY, I FIND CAPITALS ANNOYING as I find "most definitely" from the unskilled, untrained, unqualified

 

1 hour ago, facthunter said:

You are the Master of a Vessel. 

 

That is indeed correct but in itself does not guarantee liability or guilt - I am not interested in entering into "strict liability" debate - this forum is certainly not the place for that.

 

[facthunter]

This matter should have been covered before you ever went solo. Peter. IF you ever get blamed for causing damage or injury or worse you will find out the Hard way. Also , you have NO WAY of knowing my involvement or experience in these matters, so don't JUST lump me in some category that  suites your argument.. Capitals are shouting or for EMPHASIS. When you are "In command" the buck stops with you.  YOU task is to achieve the SAFEST outcome in the circumstances. Not save the company money, or get home sooner.  Lives before Property.   Nev

[peterg]

18 minutes ago, facthunter said:

This matter should have been covered before you ever went solo. Peter. IF you ever get blamed for causing damage or injury

You clearly don't get it

19 minutes ago, facthunter said:

you have NO WAY of knowing my involvement or experience in these matters

Don't I?

 

Anyway, this is my last comment on this thread - no doubt it will not be your last.

 

Ever noticed how many threads end with the last comment by you - have you ever reflected on why?

 

 

[facthunter]

Why don't you respond to the Points I made instead of getting personal ?   IF someone asks me a genuine question I try to answer it. I DO deal in facts and am aware that they may be challenged. That's part of the deal, but attacking the person is not on..   Nev

[F10]

Yes Machii jets had low melting point (lead I think) plugs in the wheel rims, so overheating brakes would cause tyres to deflate, (melted plugs) rather than the tyre to melt/explode, far more dangerous. Aquaplaning in the Machii was unpleasant as you would use differential braking to steer, when rudder effectiveness had dropped off. But that would take some pretty deep water on the runway. There was a Utube clip of some interesting experiments done by NASA, running a Boeing 737 nose gear, in a concrete trough with different speeds and water depths. once up and aquaplaning, the wheel actually comes to a complete stop, as shown by the high speed camera. This leads to the water under the tyre turning to steam and burning the tyre.  

 

The Lear jet used engine bleed air to rotate the front wheel, as a still standing wheel would generate a bigger splash touching down, sending water right into the engine intakes. Some nose wheel tyres will have a ridge on the tyre wall, to deflect water.

 

In Oman I noticed the Hawks would thump it down on the runway, a carrier type landings. I asked, and was told a soft gradual touchdown leading to lots of impressive looking smoke and drama as the wheel spun up, greatly increased their tyre wear. Made sense. 

Edited December 2 by F10

[facthunter]

When Mainwheels are aquaplaning the plane only remains on the centreline by rudder use and keel surface effect. The tyres have no grip at all. Like driving on black ice.  You can be sliding at 30 degrees to the way you are going at 130 Knots. When the tyres eventually grip you really feel the sideways force.. Staying ON the runway is critical to success..     Nev

[Blueadventures]

3 hours ago, facthunter said:

This matter should have been covered before you ever went solo. Peter. IF you ever get blamed for causing damage or injury or worse you will find out the Hard way. Also , you have NO WAY of knowing my involvement or experience in these matters, so don't JUST lump me in some category that  suites your argument.. Capitals are shouting or for EMPHASIS. When you are "In command" the buck stops with you.  YOU task is to achieve the SAFEST outcome in the circumstances. Not save the company money, or get home sooner.  Lives before Property.   Nev

Agree, those onboard persons safety first; discard any commercial pressures; (you may pay a career price later) but yourself and those onboard have been looked after.