Take the 2-minute tour ×
Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. It's 100% free, no registration required.

Watching this video (at 06:58 mark), this plane had just made a mayday landing, due to a bird-strike. Because of the right engine being shutdown, it was forced to land immediately, with a full load of fuel. The added weight of the fuel, combined with loss of the additional stopping power of reverse thrust, caused the pilots to bear down on the brakes harder and longer than would be normal in an end-of-flight landing.

The pilot requests to hold on a taxi-way after vacating the runway, during which time the firemen come up to the plane to "inspect the brakes."

What do the firemen actually do when inspecting? Are they looking for fire? Glowing brake pads? Do they use an infra-red heat gauge?

share|improve this question

3 Answers 3

up vote 12 down vote accepted

There are specific protocols that procedurally are required to be followed. Insofar as brake inspection is concerned, it would have been obvious from the trucks that there was no brake fire. It's also obvious that there's not a major amount of smoke coming from the brakes. As they approached the landing gear, they would have smelled serious brake heating. Glowing brakes would be seen then if not sooner. A close visual inspection for very light smoke and sensing the heat coming off the brakes would give them an idea of the rate of brake vaporization. It's a subjective judgement based on what they see and feel.

As I understand it, tires that dangerously overheat will explode before melting, and that's why thermal plugs are used which melt and deflate the tire to prevent their exploding.

At a landing in Nandi, Fiji (short runway) with what turned out to be a tailwind in a 747-200 at near-max landing weight, we had to use max braking, and I called for huffers to cool things down, and of course for an inspection. I exited the aircraft as quickly as possible to see how bad things were. I was amazed and alarmed to see thick dark grey smoke pouring from the body and wing landing gear wheels. I thought we were close to having a fire. However, the ground personnel assured me that there was no cause for alarm, that the smoke was just brake vaporization that would shortly stop as they blew air on them. It did, and after refueling we departed without incident.

share|improve this answer
1  
How did the passengers react when, after a touchy landing, the CO is the first to evacuate the plane? Serious question. –  dotancohen Jul 22 at 5:07
5  
@dotancohen It was a freighter, so there were no pax, and it wasn't a matter of evacuating but rather exiting the airplane in the normal matter, which involved lowering a built-in ladder-like stairs in the floor of the upper deck down to the main cargo deck, and then out the airstairs that had been brought to the airplane as usual. Just as a matter of information, if a 747 lands at near-max landing weight at the end of a leg, it's most likely a freighter. Pax 747s rarely land anywhere near max-landing weight unless they're tankering fuel. –  Terry Jul 22 at 6:00
1  
Thanks for the clarification, Terry. I did not mean to be indignant, and I know that for you it was not an evacuation but for any (potential) passengers it may have been the CO is leaving the craft first. –  dotancohen Jul 22 at 6:28
2  
@raptortech97 I really don't know the answer to that, except to say that air was what we always used. Thinking about it I would guess that the near-explosive generation of steam and shock cooling if you used water would cause problems. Air solves the problem without incurring further problems. –  Terry Sep 9 at 15:16
2  
@raptortech97 I'm not a pilot, but from the physics perspective: 1. water could cool things too much, 2. it sprays and you don't see anything, 3. you have to carry the water, but you don't run out of air (a minor problem prbbly). –  yo' Dec 18 at 20:06

The firemen are looking for fire. If a blaze does break out, they will extinguish it.

I do not know the protocol for firemen using water to cool the brakes in absence of a visible fire. Also, it looks to me like the firemen are more interested in the right engine than the brakes.

share|improve this answer
    
you don't want to have the brakes catching fire at the gate while refueling –  ratchet freak Jul 21 at 15:22
    
@ratchetfreak I'm guessing you don't want to have the brakes catch fire, ever. –  falstro Jul 21 at 15:35
6  
@falstro ratchetfreak's list of times at which you don't want the brakes catching fire was not exhaustive. :-) –  David Richerby Jul 21 at 15:48
    
but it's safer to have them catch fire on a out of the way taxiway than near the gate with all the ground crew –  ratchet freak Jul 21 at 16:07
1  
They are checking the right engine too because it is damaged and fire could break out there if there was leaking fuel or oil. The fire may have been blown out by blowing air while they flew and might intensify when they stop, so it is also important to check. –  Jan Hudec Jul 21 at 19:10

Also there is a plug mounted on the wheel so if the brakes heat up the plug melts, so that the tire will not burst. This would be something they would also check.

share|improve this answer
3  
Isn't that a matter of the tires heating up rather than the brakes? –  Nate Eldredge Jul 22 at 2:27
    
@NateEldredge: Well, the brakes can become really hot and the tires are close enough to get heated from them too. But there is not much to check there; if the plug melts, the tire deflates completely which is pretty obvious. –  Jan Hudec 2 days ago

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.