celestar From Singapore, joined Jul 2001, 244 posts, RR: 0 Posted (9 months 1 week 1 day 4 hours ago) and read 3126 times:
Several days ago, a China Airlines A330 landed in a heavy rainy day at Taoyuan Airport, and had lost its steering due to hydraulic failure, resulting in loosing control with part of its wheels into the perimeter grass field while taxing? How often do aircraft looses its engine hydraulic power after landing? I suspect this is a cover up as the most likely reason should be a pilot error due to poor visibility while taxing/landing.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 81 Reply 1, posted (9 months 1 week 1 day 3 hours ago) and read 2997 times:
Quoting celestar (Thread starter): How often do aircraft looses its engine hydraulic power after landing?
Very rarely. But, on most aircraft, the nosewheel steering is on the center system which has no direct engine source (center is usually driven by some combination of electric and pneumatic pumps). It's extremely unlikely that all hydraulics were lost, just the circuit powering the nosewheel steering.
Quoting celestar (Thread starter): I suspect this is a cover up as the most likely reason should be a pilot error due to poor visibility while taxing/landing.
It would be a terrible coverup; review of the maintenance messages or FDR would confirm or deny within a few hours.
zeke From Hong Kong, joined Dec 2006, 7719 posts, RR: 73 Reply 2, posted (9 months 1 week 23 hours ago) and read 2675 times:
Quoting tdscanuck (Reply 1): But, on most aircraft, the nosewheel steering is on the center system which has no direct engine source (center is usually driven by some combination of electric and pneumatic pumps). It's extremely unlikely that all hydraulics were lost, just the circuit powering the nosewheel steering.
On the A330 the NWS is powered by the green hydraulics, with an EDP on each engine, even in the face of an engine failure, the green system remains powered.
I suspect it would have been an electrical command for the steering selector valve to close. This may have been from another fault, e.g. landing gear sensor failure after a heavy landing, or a checklist asked for it to be turned off. The OP does not have enough detail to pin it down.
I could have been a simple matter of pilot error., taking a corner too fast when wet, or not using over-steer.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
celestar From Singapore, joined Jul 2001, 244 posts, RR: 0 Reply 3, posted (9 months 1 week 22 hours ago) and read 2523 times:
Quoting zeke (Reply 2): I suspect it would have been an electrical command for the steering selector valve to close. This may have been from another fault, e.g. landing gear sensor failure after a heavy landing, or a checklist asked for it to be turned off. The OP does not have enough detail to pin it down.
Hi Zeke, thanks for the input. What I find it interesting was the aircraft, if I read the brief new correctly, was able to recover itself back to the taxiway, all by itself. The news also stated that due to down pour of rain, the aircraft used up the whole 3000 ft of runway and turn off to the taxiway at the very end of the runway. All in all, it either suggest a temporary loss of steering control (like what Zeke is stating) or an error by the pilot, which is regretful but nevertheless should not be tolerated.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 81 Reply 4, posted (9 months 1 week 18 hours ago) and read 2178 times:
Quoting celestar (Reply 3): What I find it interesting was the aircraft, if I read the brief new correctly, was able to recover itself back to the taxiway, all by itself.
Differential braking and thrust are beautiful things. I've seen a pilot do a 120-degree corner with no nosewheel steering.
Quoting celestar (Reply 3): The news also stated that due to down pour of rain, the aircraft used up the whole 3000 ft of runway
If the rain was very heavy, ATC could have evoked low visibility procedures, the only runway exit available is the very end in these circultnces. These are the sort of conditions SQ6 crashed in.
I think you should share this report, so we can read what it actually says.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
DocLightning From United States of America, joined Nov 2005, 16802 posts, RR: 57 Reply 8, posted (9 months 1 week 4 hours ago) and read 1475 times:
Quoting tdscanuck (Reply 1): Very rarely. But, on most aircraft, the nosewheel steering is on the center system which has no direct engine source (center is usually driven by some combination of electric and pneumatic pumps). It's extremely unlikely that all hydraulics were lost, just the circuit powering the nosewheel steering.
That sounds actually very dangerous to me. Seeing as how a nosegear steering failure at the wrong time could actually send the plane careening off the side of the runway (and into the drink at a place like SFO or UIO), why isn't there a backup system for it?
peterinlisbon From Portugal, joined Jan 2006, 226 posts, RR: 0 Reply 10, posted (9 months 6 days 21 hours ago) and read 1235 times:
I was once on an AA flight where this happened and the pilot lost nosewheel steering after landing at Miami. He managed to get us off the runway using differential thrust, and then we had to wait for a tug to tow us to the gate.
Thanks for that, I read them and the avherald on the same event. None of them say the same as the
OP, seems the OP has an axe to grind against China Airlines.
The OP seems to have got their information from comments on the avherald link.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 81 Reply 12, posted (9 months 6 days 18 hours ago) and read 1060 times:
Quoting DocLightning (Reply 8): That sounds actually very dangerous to me. Seeing as how a nosegear steering failure at the wrong time could actually send the plane careening off the side of the runway (and into the drink at a place like SFO or UIO), why isn't there a backup system for it?
Loss of nosewheel steering will not send the plane "careening off the side of the runway". If you're going fast enough to careen anywhere the rudder is still functional and will do its job just fine (the rudder is powerful enough to counteract an engine out with the other engine at takeoff thrust down to Vmcg and that test is done with the nosewheel free castering). If you're going so slow that the rudder isn't helping much then you're going slow enough that differential braking works just fine.
Loss of nosewheel steering, especially due to hydraulic failure, it annunciated so the crew should know it's coming.
And there is a backup to the overall system...there are (at least) two pumps on the hydraulic circuit and two hydraulic rams on the nosewheel. You need at least a dual failure to take out nosewheel steering in the first place and, even if you take it out, it's not a dangerous condition, just one where the flight crew needs to pay more attention.
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