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-   -   A320? gardening in the stopway (https://www.pprune.org/rumours-news/98144-a320-gardening-stopway.html)

blue up 4th Aug 2003 17:26

A320? gardening in the stopway
 
EGFF had a reduce LDA of 1981m (6500-ish in old money) due to a Skyservice airbus parked just off the centreline at the start of the clearway. 3 burst tyres. Landed behind it about 3 hours after the incident. Heard the handling agents describe it as a reverser failure causing a skid.
For obvious reasons (to those of us who actually fly these things!) .......

Without dropping too many hints to any passing journalists, would anyone be able to throw light on the reasons.

Third deep night. Could have been me.

Neo 5th Aug 2003 01:00

I doubt very much if it was solely reverser failure.

fiftyfour 5th Aug 2003 01:06

The performance figures for landing distance are not dependent on a reverser working, although obviously the reversres will reduce brake wear when used. Something else probably caused the over-run.

blue up 5th Aug 2003 02:44

It was about 10 feet from the end of the tarmac, 20 degrees right but on the centreline. Running for the full 7500 feet seems a bit unusual for something along the lines of a reverser fail. 757 requires 5100-ish at normal (EGDD alt) fuel levels.
I don't know the A320 tech on brakes, so am curious as to the possibility of antiskid failure.

Anyone?

747FOCAL 5th Aug 2003 03:44

I have heard that the A320 has very poor brakes. :bored:

fireflybob 5th Aug 2003 05:33

747FOCAL, I don't know where you heard it from but my experience is that the A320 has very good brakes indeed!!

Phoenix_X 5th Aug 2003 07:01

A reverser fail wouldn't cause a tyreburst normally. But a tyreburst would easily cause any aircraft to use 7500' to stop!

Can't complain about the A320's brakes either, 747FOCAL, you are either joking or talking :mad:? :E

Norman Stanley Fletcher 6th Aug 2003 01:08

747FOCAL

There is some element of truth in what you have heard. The problem with the A320 is not the brakes themselves, which are excellent, but with the autobrakes which are invariably used for landing. The problem lies in the fact that there are only 3 settings. MAX is used for take-off in case of a high speed abort and is not recommended for landing as it would do unspeakable things to both brake temperatures and most of the occupants of the aircraft! The only 2 options left are MED and LOW. LOW takes 4 seconds to operate after touchdown and just never quite seems to come to your aid in time and MED is a bit fierce. The problem lies in there not being an interim setting to satisfy the more discerning user!

I am given to understand that the 737 has 4 settings and thereby effectively overcomes the problem the A320 has. I think most of my fellow A320 colleagues would agree with this analysis but I shall wait to see if other contributors agree or not.

Neo 6th Aug 2003 02:16

NSF -

I don't agree with your analysis. Autobrake is fine, but there is no difficulty using manual braking if either of the normal landing settings are not to your liking.

Brake effectiveness is great, much better (smoother, less snatchy and none of that horrible groaning!) than a B737.

NigelOnDraft 6th Aug 2003 02:29

NSF...

'Fraid I don't agree either... For me, Autobrake is used because it (apparently) gets the retardation going quicker than I would, and is even (so limits the brake temp difference I would generate).

However, once the aircraft is slowing, I then disengage and use manual braking to match the best / next exit. And this disengagement/transition process is much smoother than the 757/767...

So I just have to decide is it a short roll required (so Medium), medium (Low Autobrake) or long (leave it off). Except of course, don't like Med on the A319 (but suspect I'll wimp out with ABZ and select it!).

As for the CWL incident likely something led to Anti Skid needing to be selected off, and/or, god forbid, the last resort of "short applications of the parking Brake". If the latter, exceptional congrats to the crew for not blowing all 4 main tyres!

NoD

javelin 6th Aug 2003 02:30

NSF - you are quite correct

LOW - Darn it, not quite enough

MED - Oooooo, them brakes look damn hot Matilda

MAX - Ow, my :mad: nose hurts !

blue up 6th Aug 2003 05:28

Drifting 20 degrees off topic, but....

......how hard do you treat your brakes?

I agree that the 757/767 brake-disengagement is a little 'fierce' and is difficult to do smoothly (speedbrake down/autobrake switch off/hard manual brake application)
I used max auto on a heavyweight 76-300 landing flapless at Manchester (about 10,000 ft) and then disengaged to reduce the amount of heat pulled into the tyres ( Energy is proportional to the SQUARE of the speed at aplication) (?)and then apply them again as the last 3000 came into view at about 60 knots.
We discussed this afterwards and the book says to "maximise the use of the brakes" (or words to that effect). So....Stand hard on the pedals until they stop???
Am I right to believe that Carbon Densificated Brakes suffer meltdown above 1400 degrees? How easy is it to get them too hot? I know they don't start to work well until they reach 500-700 centigrade (on my racecar, at least)
ASBC in the UK offer courses in carbon brake use. Any B-Midland A3?? drivers on the list? Maybe someone w ho drive 'busses can tell us what the score is on this?

Norman Stanley Fletcher 7th Aug 2003 06:49

Thanks for your comments chaps. Maybe I should have also added that to disengage the autobrake can be very 'snatchy'. It is my experience that it is almost impossible to disengage it comfortably without it making a judder of some kind or other. I am a big Airbus fan by the way, but I do think this is an issue and may have been a factor in the incident in question.

TogaLock 7th Aug 2003 21:27

The Airbus brakes do work well, both autobrake and manual. I doubt that a reverser problem or a loss of the autobrake would result in the landing distance mentioned here.

Let's remember that Airbus's can surprise anyone at any time. The number of computers that have to agree for things to work as advertised is beyond the every day understanding of any pilot. It is for that reason we continue to see OEB's. Let's not forget that at one time there was an OEB on braking, basically giving guidance on how to arm the autobrakes in order to prevent a TOTAL loss of normal braking. It went something like: hold your breath and cross your toes while you count to 3 when arming the autobrake, but if it was a Thursday in December then make sure you use your left hand.... At least that was how I rememberd it.

Perhaps there were several factors in this case, but I'm sure all parties are interested to know what led to the stopping difficulties. But the fact remains: the airplane stopped on the runway with no damage or injuries. Not really the type of thing that would normally draw attention. Me thinks it was a slow day in the newsrooms.:hmm:

PlaneTruth 7th Aug 2003 23:59

The fine discussion of braking technique notwithstanding....

Most aircraft that end up in the weeds do so because pilots land long or hot. As those of you more savvy will agree, the length of the runway is immaterial if the aircraft touches down well beyond the touchdown zone.

Anyone know if the aircraft was in the "zone"?

PT

747FOCAL 8th Aug 2003 01:35

What I heard is they break down a lot and require more maintenance than they should. Was not saying the A320 is a bad aircraft. I actually like them. :ok:

Tree 10th Aug 2003 07:56

A320 brakes are smooth but they are very small. Use them a tiny bit on landing and they heat up well above the takeoff limit and you receive that annoying and distracting master caution while taxiing to the gate. Sure hope I don't ever have to experience a rejected takeoff on an A320.

Tree

ea340 10th Aug 2003 08:13

how about BSCU failure:{

fireflybob 10th Aug 2003 08:15

Tree, I hear brakes fans (optional extra) work very well on the A320!

Flap 5 10th Aug 2003 15:38

Tree,

A rejected takeoff is certainly not a problem. Carbon brakes work better when they are warm, and who cares if they are a bit too hot afterwards? As long as you don't point a fire extinguisher at them so they explode! Afterwards you just need a little time for them to cool down, but that is at least safe. Brake fans do indeed work well.

The problem had by this aircraft appears to be a fast and long landing where a go around may have been a better idea. However it does appear to have been a safe landing so it difficult to judge without all of the facts. But autobrake should not have been an issue - unless it didn't work properly and the pilots were not able to disengage it by pressing the brakes, something I have experienced some years ago on a 737.


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