One of lifes mysteries solved!

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We just landed and have a 2hr wait till our next flight. I had a seat with a window. I can say that airplane wheels are NOT spinning when a plane lands. They go from 0mph to fast in a split second!

Something I have wondered about for 40 years.
 
Not to worry you, but I think a Concorde plane had issues one time because of tires.
 
Originally Posted By: Chris142
Something I have wondered about for 40 years.

You could have just asked.
smile.gif
 
Originally Posted By: Chris142
We just landed and have a 2hr wait till our next flight. I had a seat with a window. I can say that airplane wheels are NOT spinning when a plane lands. They go from 0mph to fast in a split second!

Something I have wondered about for 40 years.


That was a mystery?

Now that you know that, you may be interested to know that, on many airplanes, when the landing gear are retracted, the brakes are applied to stop the tires from spinning. This eliminates gyroscopic forces on the hydraulic system and gear itself during retraction....
 
I was a crew chief on B-52's and KC-135 tankers in the 70's. We didn't call the tire shop out to change the tires until they started going "thump-thump-thump-thump".
 
Originally Posted By: Kruse
Not to worry you, but I think a Concorde plane had issues one time because of tires.


I believe they ran over something on the runway.
 
Originally Posted By: Astro14
Now that you know that, you may be interested to know that, on many airplanes, when the landing gear are retracted, the brakes are applied to stop the tires from spinning. This eliminates gyroscopic forces on the hydraulic system and gear itself during retraction....


And I always suspected the gyro forces might help the big jets go up faster...
 
Originally Posted By: Chris142
Originally Posted By: Quattro Pete
Originally Posted By: Chris142
Something I have wondered about for 40 years.

You could have just asked.
smile.gif

nobody I asked knew

Well...try Bitog next time you've got a question, then!

grin.gif
 
Originally Posted By: Astro14
Originally Posted By: Chris142
We just landed and have a 2hr wait till our next flight. I had a seat with a window. I can say that airplane wheels are NOT spinning when a plane lands. They go from 0mph to fast in a split second!

Something I have wondered about for 40 years.


That was a mystery?

Now that you know that, you may be interested to know that, on many airplanes, when the landing gear are retracted, the brakes are applied to stop the tires from spinning. This eliminates gyroscopic forces on the hydraulic system and gear itself during retraction....


I find it interesting how different aircraft accomplish the act of slowing the tires upon gear retraction. On the P-3 the main mounts had a shuttle valve that applied the brakes upon gear retraction, the nose gear had an "aero" brake that sat very close to the nose tires upon full retraction that used the air near the tires to slow rotation. The P-8 also applies the brakes on the main mounts to stop the tires upon hear retraction, the nose gear has a pair of pads that are spring loaded that act on the tires to stop them with direct friction on the tire itself.
 
Originally Posted By: Astro14
Originally Posted By: Chris142
Originally Posted By: Quattro Pete
Originally Posted By: Chris142
Something I have wondered about for 40 years.

You could have just asked.
smile.gif

nobody I asked knew

Well...try Bitog next time you've got a question, then!

grin.gif



Astro, put that smart phone down and get back to flying the plane.
cool.gif
 
Originally Posted By: tig1
Originally Posted By: Kruse
Not to worry you, but I think a Concorde plane had issues one time because of tires.


I believe they ran over something on the runway.


Correct. A flight taking off prior to the Concorde lost some sort of titanium-alloy strip. This punctured one of the tires of the Concorde when it ran over the item, and caused it to disintegrate. One piece of the tire struck the underside of the wing near a fuel tank which then set a chain of events in motion which caused the tank to rupture.
 
Originally Posted By: Chris142
We just landed and have a 2hr wait till our next flight. I had a seat with a window. I can say that airplane wheels are NOT spinning when a plane lands. They go from 0mph to fast in a split second!

Something I have wondered about for 40 years.


is that you, merk?
 
Ultimately the verdict with the Concorde was that no matter why the tire blew, it was inherently unsafe to fly when a simple tire blowout during takeoff is likely to cause serious damage to the aircraft, resulting in a fatal crash. So they were all grounded.
 
Originally Posted By: mk378
Ultimately the verdict with the Concorde was that no matter why the tire blew, it was inherently unsafe to fly when a simple tire blowout during takeoff is likely to cause serious damage to the aircraft, resulting in a fatal crash. So they were all grounded.


It wasn't that simple - tires had blown on Concorde before...with no serious result.

But this tire blew and sent some big chunks of rubber into a vulnerable spot on the underside of the wing. The wing was "wet" - meaning that the skin of the wing was the fuel tank, and so that chunk punctured the fuel tank, which caused the TWO engines on that side to compressor stall and lose thrust.

Conventional four engine airplanes can't take off at maximum weight with two engines inoperative.

And neither could Concorde.

It was already above the speed at which it could stop, so they continued the takeoff, but with two engines out, they had no chance...

When the results of the accident were determined, the certification authorities required armor on the bottom of the wing to prevent a future puncture. That was simply too expensive (not to mention deleterious to its performance) on an airplane that had a dozen models flying. Interestingly, the airplane was profitable for BA, but a net loss for Air France, who kept it flying out of pride.

So, it was retired. Still a marvel of engineering. Still a marvel of performance.
 
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