One of lifes mysteries solved!

[Astro14]

Originally Posted By: Papa Bear


Astro, put that smart phone down and get back to flying the plane.

I'm hanging out at the EWR airport Marriott - awaiting an assignment this evening. Couldn't make it home last night, and they called me at 11:00 last night anyway to have me on field standby (dressed and ready to go at the airport) here starting at 17:00...so, after breakfast and the gym, and calling my family, what else is there to do but check out BITOG?

 

[4WD]

Well … they make a good burger

 

[Yah-Tah-Hey]

Originally Posted By: FlyNavyP3
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.
"main mounts" First time I have seen that term in many years. Feliz Navidad Navy guy.

 

[ThankYouma]

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.


They don't make the Concord anymore.

 

[aquariuscsm]

Originally Posted By: ThankYouma
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.


They don't make the Concord anymore.


My uncle flew on the Concorde and said it was amazing!!

 

[john_pifer]

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.


You’ve wondered about that for 40 years?

What did you think was happening? How would the wheels be spinning?!

 

[DoubleWasp]

Assumed windmilling maybe?

 

[Yah-Tah-Hey]

What do you think all that smoke is coming from? Tires being dragged

 

[SWS]

This is an interesting topic. I don’t know much about airplanes, but love to read, listen & learn. I was first told back in the 1970’s that the very large, heavy jets (e.g. 747, C5 Galaxy) had severe tire blow-out issues during development & test, requiring addition of motors in the wheel hubs to speed-up the tires a bit just before touchdown.
I know that most airplanes don’t do this, but do NONE of the heaviest planes also not implement this?

 

[Astro14]

Originally Posted By: SWS
This is an interesting topic. I don’t know much about airplanes, but love to read, listen & learn. I was first told back in the 1970’s that the very large, heavy jets (e.g. 747, C5 Galaxy) had severe tire blow-out issues during development & test, requiring addition of motors in the wheel hubs to speed-up the tires a bit just before touchdown.
I know that most airplanes don’t do this, but do NONE of the heaviest planes also not implement this?


No, whoever told you that was misinformed.

The wheel hubs are completely taken up with brakes. BIG brakes on those large airplanes. Google "747-800 Rejected Takeoff" and watch the Youtube video of those brakes glowing bright orange after absorbing all that energy.

 

[john_pifer]

Check this one out, guys. Airbus A340-600 RTO test. Turns into a real cluster when the ground crew sprays cold water onto the RED HOT brakes and very hot wheels!

https://youtu.be/lUMuOyMTQ8Y

 

[Yah-Tah-Hey]

Originally Posted By: Astro14
Originally Posted By: SWS
This is an interesting topic. I don’t know much about airplanes, but love to read, listen & learn. I was first told back in the 1970’s that the very large, heavy jets (e.g. 747, C5 Galaxy) had severe tire blow-out issues during development & test, requiring addition of motors in the wheel hubs to speed-up the tires a bit just before touchdown.
I know that most airplanes don’t do this, but do NONE of the heaviest planes also not implement this?


No, whoever told you that was misinformed.

The wheel hubs are completely taken up with brakes. BIG brakes on those large airplanes. Google "747-800 Rejected Takeoff" and watch the Youtube video of those brakes glowing bright orange after absorbing all that energy.
I remember watching a film for Skydrol when I was working on the A part of my A&P. Won't mention the school but some may know from past posts. The film showed Skydrol being sprayed on red hot aircraft brake assemblies with lots of smoke but no fire. Never put a wrench on an airplane but went to work in power generation. On the EHC (Electro Hydraulic Control) units used to actuate the main steam and stop valves (1005 F) a product called Fyrquel was used in the 400 gallon reservoirs on the EHC units which operated at 3000 psig. This fluid was very similar to Skydrol. It would produce a very irritating smoke when sprayed on very hot main steam lines but would not catch fire.