MH134
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MH134
See http://www.facebook.com/AIRLINESECRE...10636529209353 and Investigation: AO-2018-053 - Airspeed indication failure on take-off involving Airbus A330, 9M-MTK, Brisbane Airport, Queensland, 18 July 2018
How did that crew make any kind of V1 abort/continue decision, with no airspeed indications? WTF
How did that crew make any kind of V1 abort/continue decision, with no airspeed indications? WTF
Last edited by drpixie; 25th Jul 2018 at 12:28. Reason: Add text for link that that gets screwed up
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Anything the Brissy wasps can do, humans can do better! 
All jokes aside, it is a serious incident where several inspections failed to pick up the presence of the covers.
One would think airspeed anomalies, or lack of indicated airspeed may have been picked up earlier, but I'll leave all judgement to the investigators.
All jokes aside, it is a serious incident where several inspections failed to pick up the presence of the covers.
One would think airspeed anomalies, or lack of indicated airspeed may have been picked up earlier, but I'll leave all judgement to the investigators.
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I learned my lesson some time back. This serves to remind me NEVER be tempted to fly Malaysian.
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Pitot covers installed are made of fabric so they don’t melt if pitot heat comes on with them installed. This fabric let’s a small amount of air through like a very dense filter. It’s possible airspeed did register up to a certain point as there would still have been some pressure getting to the probe.
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All jokes aside, it is a serious incident where several inspections failed to pick up the presence of the covers.
Also, the ground handling agents apparently installed Boeing pitot covers instead of Airbus pitot covers. Apparently the Airbus covers are designed to disintegrate when the Probe heat is turned on.
Finally, the decision was made to continue even though they did not have accurate airspeed indications and once airborne, Airbus being Airbus, the screens all went blank because the ADIRU’s couldn’t work out what was going on.
It’s amazing that they even got it back on the ground in one piece, albeit with a heavy landing.
. We conduct external pre-flight inspections all the time with the covers on as they are removed by Mx personnel closer to departure time.
Our (Airbus) covers are woven from kevlar, and I don't get the sense that anything short of an oven would compromise them. In fact they are made specifically not to melt; perhaps there is something about their construction that makes them unravel?
The screens don't go blank during an unreliable airspeed event....in fact pilots are expected to fly attitude and power to a safe conclusion.
There is also a back-up speed scale that, when selected by turning off air data, displays fast/slow cues based on alpha. That system (BUSS) may in fact be a a factory option, and if so, MH may not have it installed* (see below)
Unreliable airspeed in an A330 is a non-trivial, but manageable event. That said, its pretty unlikely to cross the fence at exactly the optimum speed, and a heavy, slow aircraft bleeds energy quickly. Its not difficult to see how either a hard or long landing might result, especially with rarely used manual thrust.
On edit...I was curious about the BUSS. Deeper research reveals that BUSS might be optional even on later build aircraft.
Our (Airbus) covers are woven from kevlar, and I don't get the sense that anything short of an oven would compromise them. In fact they are made specifically not to melt; perhaps there is something about their construction that makes them unravel?
The screens don't go blank during an unreliable airspeed event....in fact pilots are expected to fly attitude and power to a safe conclusion.
There is also a back-up speed scale that, when selected by turning off air data, displays fast/slow cues based on alpha. That system (BUSS) may in fact be a a factory option, and if so, MH may not have it installed* (see below)
Unreliable airspeed in an A330 is a non-trivial, but manageable event. That said, its pretty unlikely to cross the fence at exactly the optimum speed, and a heavy, slow aircraft bleeds energy quickly. Its not difficult to see how either a hard or long landing might result, especially with rarely used manual thrust.
On edit...I was curious about the BUSS. Deeper research reveals that BUSS might be optional even on later build aircraft.
Last edited by Australopithecus; 8th Aug 2018 at 02:31. Reason: Third edit of BUSS as standard or optional equipment
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Have heard from a fairly reliable source that no Flightcrew were observed conducting a pre-flight walk around.
Also, the ground handling agents apparently installed Boeing pitot covers instead of Airbus pitot covers. Apparently the Airbus covers are designed to disintegrate when the Probe heat is turned on.
Finally, the decision was made to continue even though they did not have accurate airspeed indications and once airborne, Airbus being Airbus, the screens all went blank because the ADIRU’s couldn’t work out what was going on.
It’s amazing that they even got it back on the ground in one piece, albeit with a heavy landing.
When the air data side of the system decides that all its pitot-static data is unreliable it automatically displays the BUSS on both PFDs in the A330. The BUSS uses only data from the AOA vanes on the airspeed tape side of the display. That's a "normal" reversionary mode on the aircraft built into the system software.
How & why they got airborne, I have no idea.
Dutchy
Current A330 pilot
Eng 2 inop?
maybe a frivolous pic there
But the BUSS is accurate what you're looking at instead of a speed tape
maybe a frivolous pic there
But the BUSS is accurate what you're looking at instead of a speed tape
When the air data side of the system decides that all its pitot-static data is unreliable it automatically displays the BUSS on both PFDs in the A330. The BUSS uses only data from the AOA vanes on the airspeed tape side of the display. That's a "normal" reversionary mode on the aircraft built into the system software.
Last edited by BuzzBox; 8th Aug 2018 at 08:22.
I guess other newer Airbus’ are the same, but new A320’s have a simple push button on the panel to display the BUSS.
A flight Global article from 2007 announced the developement of the BUSS, but I just found this Airbus article from 2007 which states that the BUSS is OPTIONAL on the A330
https://static.mediapart.fr/files/Joelle_Barthe.pdf
Last edited by Australopithecus; 8th Aug 2018 at 02:09.
Further to my last, Airbus has a free app for their “Safety First” magazine. In the archive section, edition 3 is an article on blocked pitot tubes on the ground, and an earlier 330 incident is cited. Recommended reading.
To mevthey look more like something taken for or during a simulator exercise.
