fuse plug question~

[citizensun]

could anyone tell me the function of the fuse plug installed in the landing gears. the book says: radiated and conducted heat from the brake may cause a wheel fuse plug to melt to release air pressure from the tire safely.
what for?
to avoid the tire blowed and the debris hit the airframe to cause damage?
thanks~

[KBPsen]

what for?
to avoid the tire blowed and the debris hit the airframe to cause damage?

Yes.

And then some filler

[citizensun]

with the tires deflated ,what is responsable for the decelaration of the aircraft? still the baking disc?

[FlyingStone]

If you compare the aircraft tire to a car tire: wheel with flat tire on a car would still turn if the car is moving, yes? And if the wheel is moving, the braking disc is turning and therefore the braking is possible.

[bcgallacher]

In my experience it takes some time for heat to soak from the brake unit to the wheel and heat it to fuse melt temperature - this has resulted in the fuse blowing after arrival on the parking area. I have had a 747 blow all 16 fuses after an overweight landing following an engine failure on takeoff - they let go one after another on the gate.

[Touchin' Down]

The purpose of a fuse plug is to allow a tire, that may otherwise explode, to deflate in a controlled manner. This makes it safer for any approaching fire crews, as well as for the reasons you mentioned.

The times a fuse plug is likely to 'blow' is following a high speed landing or rejected takeoff, where heavy braking has been used.

It is more likely the tire would deflate following the aircraft stopping, not during the actual stopping event. This is because after the aircraft has come to a stop heat is still being transferred to the tire from the brake units so the temperature of the tire will continue to increase. If the tire does deflate while the aircraft is still moving, braking effectiveness is greatly reduced, so they are designed for this not to occur.

[clunckdriver]

Citzensun, When one considers that even on a small jet {DC9} the cold tire pres is 220 PSI it is vital to have them deflate without exploding, if you can get into an aircraft tire shop you will see that they are inflated inside very strong cages, also if you should have hot brakes for heavens sake dont stand along side the wheel, if you must get close do so from directly in front or behind, less chance of getting your head blown of this way.You proberbly know but aircraft tires are normally filled with nitrogen, not air.

[an3_bolt]

Just couldn't help it - one of my favourites.....hRzWp67PIMw

And another good example where you can see the brakes quite hot and the fuse plugs in action - f4LFErD-yls&NR=1

.....also with the parking brake engaged - it will heat up the brakes / tyres - if you have a heavy braking event or quick turn around - it can assist by having chocks placed and releasing the park brake once on the parking bay.

[clunckdriver]

AN3, I spent the day sorting AN/Mill Spec hardware after a field trip, so you handle is perfect, also you vid makes my post redundent, Perfect! Thanks, Clunck.

[Lightning5]

If you hear it hissing, walk away (quickly ) !!!

[spannersatcx]

This is what happens when they explode injured inflating a tyre (http://www.pprune.org/engineers-technicians/350808-lh-engineer-seriously-injured-man-13th-nov.html)

[citizensun]

thanks a lot ~an3_bolt
very nice videoes~
could anyone tell me how a melted fuse plug deflate the tires?
thx~:ok:

[spannersatcx]

The core of the plug is designed to melt at a pre determined temperature, once it melts a nice hole is there for all the N2 to escape.

[citizensun]

thank you spannersatcx,:ok:
i don`t want to see that hole though~