View Full Version : AAsia flatout
flightleader
3rd Feb 2006, 02:13
Some time between 0900 to 1000 utc yesterday,AAsia brand new A320 9M-AFA blown all 4 main wheel upon arrival at the gate in KCH,seems like fuseplug melted,anyone know what happen?
The Rage
3rd Feb 2006, 02:24
Again, not another one!
Dont worry Good Old Tony's freinds at the PR Dept will handle this, u wont hear a thing about it.
Not surprised if pilots were coming onto the A320 from B737. Foot action is different when applying brakes. On B737, one has to move feet to the top of rudder pedals and apply some amount of downward motion. If a pilot does this on the A320 at a speed above 90 knots, the plane will come to a screeching halt with the brake temps getting extremely hot. Proper braking technique on the A320 is a rocking motion from the bottom of the rudder pedal to the top.
Nonsense, A320 has Antiskid, you can treat your rudder pedal as much as you can, you never can destroy your brakes or wheels - unless you do something really wrong (like switching off your Antiskid, or forgetting your brake temperature, or ...)
Dani
Wizofoz
3rd Feb 2006, 16:15
Dani,
Crap. Antiskid is just that. It stops the wheels from skidding. It doesn't stop the enourmous heat transfered during heavy braking from causing thermal plugs to melt or contaminents on the discs (such as grease and oil) to burn.
I once had a 140+ knot RTO in a 767. The wheels didn't skid, but five out of the eight main wheel thermal plugs melted (as they are designed to do)!
Anti-skid is NOT a catch-all protector of your wheels and brakes.
2000 hours of line training on the A320 backs what I said above. Invariably when a student displayed consistent heavy braking, they had their feet on the upper lip of the rudder pedals. The energy from going from 100 knots to 30 knots in a matter of a second or two must go somewhere and I can guarantee it is in the brake assemblies.
Well, I don't know how you fly the bus but if the message is "four blown tyres" then I assume that they are blown, not flat, which is a kind of a difference. Antiskid is the flavour of the day for not to blow tyres, agree?
I agree that you can heat up your brakes up to 800°, where thermal fuses hack in, but you really have to to something wrong if you want to do that on a 320 and 2500 m RWY. So far, my statement above remains.
And 767 might be a bit of a difference (maybe three times the weight?) to a mini bus?
btw, I refered my "nonsense" statement to the way the difference of brake pedals have been described above. There might be differences, I do not fly the 737, but you can simply press that thing, nothing more, nothing less, if you press too hard, then you brake too hard. No rocket science. The main difference in brakes lies in the material: If you have flown an old 737 with iron brakes, you might encounter problems with the carbon brakes of a modern 737 or a 320 (or a F100, or a 777, or...). The key lies in the brake temperature, cold brakes are not efficient, and the first second nothin happens, until you apply more pressure, and suddenly the brakes become very effective. This has nothing to do with foot position on your brake pedal.
Keep discovering,
Dani
Dani, next time you fly your airbus, why don't you try to brake with you feet on the upper lip of the rudder pedal. I guarantee you will not do it again. Since you haven't flown the B737, I don't see how you can intelligently comment on my explanation. The initial message on the thread might have said "blown" but then referenced fuseplugs btw.
Cross Check
4th Feb 2006, 11:40
Not too long ago I heard someone mentioning some differences between the two a/c - one of those being steel brakes on the 320 vs. carbon brakes on the 737.
Nothing unusual about the landing in KCH according to Engineering. Remember maximum heating in the brake system can often occur some minutes after touchdown during taxi or even after parking if the taxi is short - hence chocks in/brakes off. Aircraft was parked however the hub ventilation fans were not manually selected on and the inevitable happened :uhoh: presumably a crew oversight. Surprising with all that automation and "system protections" the extractors don't just start up themselves... :suspect:
Hi guys,
Can't really make any intelligent suggestions here. I know there is a difference in braking technique between carbon brakes and steel brakes, but on the Boeings, we try to manage brake energy by using maximum reverse and leaving the autobrake to do the work until approximately 60 knots. Anyone can enlighten me how the bus drivers manage brake energy on the 'minibus'?
Cheers...
The only time I use manual brakes is light aircraft and long landing roll. Even then, no braking till runway exit. Auto-brake especially useful in crosswinds.
...and the only time I use autobrake is on short RWY and contaminated and/or autoland. Normally on 2000-2500 m plus landing roll you don't need any brakes at all before taxi speed, if you use normal reverse (that's the airbus name for full reverse). My brake temperatures hardly ever exceeds 150° (limit for TO 300°). With autobrake on, even on low, you always reach 300° and more, especially on crosswind.
Can someone confirm that AirAsia has their A320 equipped with brake fans? It's only an option.
On a short strip where moderate to heavy braking is necessary, you get the brake temps rising about 2-3 minutes after you left your RWY. Airbus recommends not to switch on your brake fans 3 minutes after landing, to reduce oxidation. As a responsible pilot you try to start the blower before you reach the gate, since those karbon brake particals are somewhat dangerous (cancerogene, for ground staff). After about 5 to 10 min you will get the 300° "BRAKES HOT" caution, with the ECAM checklist "Brake fan ON". It's hard to overlook such a message. Although Airbusses are highly computerized, it hardly ever does something on its own. Airbus philosophy is to keep the pilot in the loop. So you have to switch on your brake fans by yourself.
Okie, I always brake on the upper part of the brake pedal. What do you mean with lid? There is no twofold pedal, it's just what it is, since you flew your Cessnas: lower part: steering, upper part braking - really nothing to worry about.
Dani
A330AV8R
5th Feb 2006, 01:33
DANI
Just a minor correction mate Max brake temp on A320 = 900 c NOT 800 and trust me that makes a world of difference .
Don't know who said rocking motion for breaking but hes right !
:ok:
Gnadenburg
5th Feb 2006, 05:16
Airbus have various brake models for different aircraft. Some here have regurgitated FCOM, with authoritive ad nauseam, without realising all parties have varying degrees of correctness.
Looking at it pragmatically, Okie is on the mark. Unusually hot brakes have been attributed to poor braking technique as described.
A brake fan out on one side can be a big problem too- leading to deflation a little easier than expected. Brakes encased with brake fans have a tendancy to heat very quickly with unservicable brake fans.
Dani, I said lip not lid. If you have a look at your break pedal on the next flight, you will see a raised section at the top. I assume that it is there to prevent one's foot from going too high on the pedal. A few ex-B737 pilots place their foot on top of this raised area because that is the action they used on that plane. This makes it very difficult to "modulate" the application of brakes. A line training captain's main job is to identify a problem and find the solution. Amazingly when I asked the students who had this problem where their foot was on the pedal, every one had their feet as I have described. Every one of them had no problem after they changed the position of their feet. I realize that you might think this is stupid and it couldn't happen. I was only trying to help someone that might have the problem in the future. No more posts from me on this subject.
Dani, I said lip not lid. If you have a look at your break pedal on the next flight, you will see a raised section at the top. I assume that it is there to prevent one's foot from going too high on the pedal. A few ex-B737 pilots place their foot on top of this raised area because that is the action they used on that plane. This makes it very difficult to "modulate" the application of brakes. A line training captain's main job is to identify a problem and find the solution. Amazingly when I asked the students who had this problem where their foot was on the pedal, every one had their feet as I have described. Every one of them had no problem after they changed the position of their feet. I realize that you might think this is stupid and it couldn't happen. I was only trying to help someone that might have the problem in the future. No more posts from me on this subject.
......... presumably because the BRAKE pedal is broken.
Cross Check
6th Feb 2006, 18:25
AirAsia has taken the option then for brake fans on aircraft delivered so far.
Well, IF they overlooked an ECAM then I guess that's an endictment of 25 minute turn-arounds with inexperienced crews struggling to remain (or more likely get back) on schedule. :(
The Rage
15th Feb 2006, 14:04
Let's just say they landed long, very long.
MAStake
16th Feb 2006, 08:34
And let's add that they landed fast, very fast.:E :E :E