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A 320 G+B failure-to taxy or not to taxy?

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A 320 G+B failure-to taxy or not to taxy?

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Old 27th Oct 2019, 07:13
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A 320 G+B failure-to taxy or not to taxy?

After landing with G+B failure, will one taxy with the remaining Y system since NWS is still supplied by the Y system(In the later version of A320) or request for towing assistance?( The gear doors are left open after L/G gravity extension)
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Old 27th Oct 2019, 08:49
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Got brakes, got steering, why not.
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Old 27th Oct 2019, 09:32
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Yes! Blue system is irrelevant on ground. Yellow gives you alternate braking with A/SKD though not applicable at taxi speed. Nose wheel steering and parking brake is available. So why not go and park.
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Old 27th Oct 2019, 10:01
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Yes! Blue system is irrelevant on ground. Yellow gives you alternate braking with A/SKD though not applicable at taxi speed. Nose wheel steering and parking brake is available. So why not go and park.

Nose wheel steering is enabled with hydraulic pressure when:

Nose gear doors closed.
A/SKID & N/W STRG switch on.
Towing control lever in normal position.
At least one engine operating.
Aircraft on the ground.

Nose wheel steering is disabled after manual gear extension.

So call for the tug for Towing assistance.
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Old 27th Oct 2019, 11:12
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According to the FCOM that restriction doesn't apply to newer aircraft with yellow system NWS, it remains available with the gear doors open.
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Old 27th Oct 2019, 13:30
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The steering system receives actuating hydraulic pressure when:
‐ A/SKID & N/W STRG switch is ON
‐ Towing control lever is in normal position
‐ At least one engine is running
‐ Aircraft is on ground.
Nothing to do with gear doors.
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Old 27th Oct 2019, 17:25
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I wouldn’t without having an inspection first.
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Old 27th Oct 2019, 17:58
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Originally Posted by EcamSurprise

I wouldn’t without having an inspection first.
Exactly. Would you want to be taxiing when hydraulic fluid could be dripping everywhere and the brake discs are hot?
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Old 27th Oct 2019, 18:38
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True, I landed at NCE years ago in a B733 with HYD SYS “A” empty (O ring seal perished, hence leak). No NWS, A/P 1 u/s, REV 1 inop, Gear gravity extension (I think), “A” system Spoilers up-floated on Final, they shouldn’t have (landed with 90 degree control column deflection to stop adverse roll). Vacated 04R using differential braking and stopped between the parallel runways without disrupting traffic. ATC advised smoke from ENG 2. Wrong! it was HYD “A” system fluid vaporising onto the hot brakes below ENG 1. Anyway, towed onto a remote stand where the DGAC appeared and pulled the CVR circuit breaker. My F/O told him where to go, while I completed the Tech Log.
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Old 28th Oct 2019, 06:56
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There are a few reasons for loosing G+B not necessarily only fluid leak. Brakes are available for use. Its captain's call to consider them and convey to ATC how far will he taxi after clearing the runway.
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Old 1st Nov 2019, 05:04
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Originally Posted by vilas
Nothing to do with gear doors.
True...nothing to do with the gears...the gears had to do with G+B failure in classic A320 when the NWS was supplied by the G system. In the enhanced version of A320, NWS is activated by Y system.
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Old 1st Nov 2019, 05:17
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Originally Posted by EcamSurprise

I wouldn’t without having an inspection first.
Agreed. The figure 300 as maximum brake temperature limitation is to avoid igniting the hydraulic fluid in case of a leak. If the brake temperature is close to 300, I wouldn't do anything that would increase the temperature further. So, I would definitely get it inspected. If I am sure that the fluid has not come in contact with brake units, I may consider taxying further...
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Old 1st Nov 2019, 07:56
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What do you reckon the brake temperature will be, after a slat-less landing with no antiskid and partial spoilers?
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Old 1st Nov 2019, 10:20
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Originally Posted by FlightDetent
What do you reckon the brake temperature will be, after a slat-less landing with no antiskid and partial spoilers?
It would depend on the ground speed when the brakes were applied and mass of the aircraft.
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Old 1st Nov 2019, 14:11
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What do you reckon the brake temperature will be, after a slat-less landing with no antiskid and partial spoilers?
Why no anti skid? It's not G+Y. It's not accumulator braking. You will have alternate brake with antiskid and No2 reverse available with spoilers 2 and 4 not a problem.
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Old 1st Nov 2019, 17:21
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Sorry, antiskid is there indeed. Stopping is not a problem, but IMHO the temperature will be well above the usual indications.

E(k) at landing is increased by sizeable 40%
only one reverser
2 4 spoilers instead of full 10 pieces

Formally, I also asked about the brake temperature not what's indicated on the SD/wheel pg. Initially seeing the same as post #2, I like the thread that it has changed my mind.

The last night at 56 t and OAT 16 deg C:
+ controlled landing at 450 m past thr
+ 2x full REV
+ LO a/brk until 50 kt
+ vacate at 2400 m
+ 9 mins taxi with alternate L/R applications
= 285 indicated on all four, give or take upon reaching the gate.

The question still stands, for a number that is.

Last edited by FlightDetent; 2nd Nov 2019 at 16:06. Reason: vilas watching over us
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Old 2nd Nov 2019, 03:35
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2 spoilers instead of full 10 pieces
Sorry again but it's 2 either side makes 4 out of ten. B+G is a handful in handling but after touch down it is just managing 25kts addition to the Vref. If LDA is descent and with brake fan shouldn't be a problem.
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Old 2nd Nov 2019, 20:32
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For whose benefit are you going to taxi in? Forget the crap about keeping the runway open. All the time the AFS are in attendance dealing with your broken Airbus, the airfield will stop all departures and arrivals.

Having got the thing on the ground with one remaining system and a Direct Law landing, why risk it all for something that you have never been trained to do?

Park brake on. Shut down the engines and put your feet up. This is now somebody else's problem.
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Old 3rd Nov 2019, 05:06
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With NW steering, brakes available for taxiing why would you block the active runway? You done great job why reduce it's value? If it was G+Y then may be you just stop wherever.
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