Data Entry Blunders Force Air Asia Pilots To Land in Melbourne Instead of Malaysia (mashable.com) 84
A flight from Sydney to Malaysia ended up in Melbourne after the captain incorrectly entered the plane's location in its navigation system just before take-off, according to a safety investigation, whose conclusion was published this week. Mashable reports:The Air Asia pilots made several errors in entering data into the aircraft's navigation system, which caused them to follow an incorrect flight path out of Sydney, according to Australian transportation officials. While troubleshooting the incorrect flight path, the pilots were unable to fix the issue, and may have compounded it. The aircraft's systems would not allow the plane to be flown in instrument conditions and the weather also had deteriorated in Sydney by the time the pilots decided to turn back. They were directed via radar to a visual approach in Melbourne where they could land safely. The pilots did not believe the airport was located in Malaysia.
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And ffs if they could fly the stick why didn't they just fly the stick to Malaysia?
Right. They should have just followed the railroad tracks.
Sydney to Kuala Lumpur is over 6600 km, lots of it over water. Sydney to Melbourne is about 700 km, all over land.
Re: What? (Score:5, Informative)
OK, here's what really happened:
The captain entered the wrong coordinates into the Inertial Reference System, which is the airplane's primary reference for position. Normally, there are several ways the system could have detected this:
- It is normally updated by GPS, but if the difference between the two is too large, the sytem considers the GPS to be faulty. Some warning messages were given, but these warnings often occur during normal operation on the ground and then disappear afterwards, so pilots are sort of "trained" by experience to disregard them.
- When applying take-off thrust, the system normally realigns to the coordinates of the runway. But, thanks to genius Airbus programming as usual, the system did not perform the update because the error was too large.
- If an incorrect latitude is entered, the system can detect the error because it measures the earth's rotation vector and the gravity vector during IRS alignment while the airplane is still parked. In this case the longitude was incorrect, which cannot be detected by the system. The earth rotates the same at any longitude.
After Take-off, two problems arose:
1. The position was way off, the plane actually thought it was somewhere close to South Africa
2. The Enhanced Ground Proximity Warning System activated, yelling "Terrain, terrain!", based on the incorrect position (not a big problem, but confusing as hell and creating extra stress for the pilots).
3. The heading indication was incorrect, because the IRS internally knows only the true heading (relative to true north) while heading indications on aircraft systems are relative to magnetic north for historical reasons. The IRS converts between the two using local magnetic variation (the difference between magnetic north and true north) but, because it thought it was near South Africa, it used the wrong value for the variation and therefore displayed an incorrect magnetic heading. This caused the autopilot to turn the wrong way.
The pilots, fearing that something was wrong with the entire Air Data Reference system, applied a procedure for unreliable airspeed (they did not know which instruments they could trust anymore) and turned off two of the three ADR computers. This resulted in a further loss of information displayed on their screens which was not exactly helpful to their situation. The procedure exists to disable certain safety protections that might accidentally activate based on erroneous data (if two of the three computers say the airplane is stalling, the flight control computers will push the nose down and override the pilots' sidesticks) but in this case this procedure was not necessary and actually made their life harder.
Now, if you've lost half your instruments, you don't know which instruments you can trust and which you can't (with the heading being wrong for certain), it's not a good idea to fly on instruments through clouds at low altitude. Certainly not an approach to a runway without being able to see it. So they needed to go to an airport where the visibility and cloud base allowed a visual landing. The closest suitable airport with good weather was Melbourne, so that's where they went.
Re:What? (Score:4, Informative)
This is because the paragraph above was posted as a correction to the article.
Otherwise the article gives the impression that the pilots were so incompetent as to not even realise which country they were in.
I feel slightly dumber (Score:2, Insightful)
Mashable reports...
That summary is such a hodge-podge of disconnected half-facts. A link to a publication written by trained journalists, or even trained monkeys, might be more coherent.
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In related news ... (Score:5, Funny)
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A link to a publication written by trained journalists, or even trained monkeys, might be more coherent.
Before you blame Slashdot for half facts, remember trained and paid journalists are able to come up with headlines such as these:
"AirAsia pilot ends up in Melbourne instead of Malaysia after navigation error" [theguardian.com]
As bad as it is, Slashdot has produced better journalism than The Guardian's headline.
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The actual Australian Transport Safety Bureau report [atsb.gov.au]
The main take-away:
When manually entering the coordinates of the aircraft's position using a data entry technique that was not recommended by the aircraft manufacturer, the longitude was incorrectly entered as 01519.8 east instead of 15109.8 east. This resulted in a positional error in excess of 11,000 km, which adversely affected the aircraft's navigation systems and some alerting systems.
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And everybody thinks they're crap at driving...
MH370 (Score:1)
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That's a jumbled mess of nonsense but what i think you're trying to say is that the path MH370 took looked as if it was plotted with the goal of avoiding detection.
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MH370 made an turn towards an airports. Like there was a fire on it and they turned to nearest safest airport
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Umm, right. You don't just 'unhook' the autopilot and stuff in a new one. This is not a car stereo.
I suppose you could just sneak a 777 off the tarmac a bit ('hey guy's, it's cool') and rip out the cockpit guts and stuff your new black box in, do extensive system checks, button up everything and sneak it back. Without anybody whatsoever noticing.
But I doubt it.
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Technically, you would be playing with the avionics bay below the cockpit, but still.
While it would be possible given sufficient access and knowledge, it would be a heck of a lot less effort to try and fly it away when "nobody is watching."
Re: MH370 (Score:1)
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Combined with a sudden radio silence and switched off transponder? Not likely. If they were simply flying in the wrong direction ATC would see that immediately, as in this Air Asia case.
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Now, I must admit TFA seems to be lacking quite a few details, plus the style sheet won't load for me.
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Further researching the incident I guess my information source (apparently an old documentary series called "Mayday") was a tad bias, they appear to have taken the pilots view to heart that the fly by wire system delayed increasing power and when he pulled back on the controls the aircraft failed to even attempt to climb (possibly an anti-stall measure as you mentioned). The pilot had every reason to remember events that put him in a better light, that said though some pretty shady things patiently happene
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Posts like yours make me wonder if people are trolls or just morons.
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If they hadn't done that it would have been too obvious. (For pretty much any values of "they" and "it")
Actual link (Score:1)
http://www.atsb.gov.au/publications/investigation_reports/2015/aair/ao-2015-029/
"Initial Position" Error (Score:2, Interesting)
Navigation grade inertial nav systems need to know their initial position in order to perform accurately. According to the Australian Transport Safety Bureau report, an erroneous longitude value was entered prior to takeoff. This is very curious, as initial position is supplied automatically from GPS, unless (1) GPS is not available; or (2) the system is very old and doesn't have that feature. If the latitude is correct but the longitude is wrong, the INS will probably align properly, but it really won't kn
Re:"Initial Position" Error (Score:5, Insightful)
From the investigation report :
The ATSB also found that the aircraft was not fitted with an upgraded flight management system that would have prevented the data entry error via either automated initialisation or automatic correction of manual errors.
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From the investigation report :
The ATSB also found that the aircraft was not fitted with an upgraded flight management system that would have prevented the data entry error via either automated initialisation or automatic correction of manual errors.
Yeah, I saw that. "Not fitted with an upgraded flight management system..." is a rather understated description, as every INS and FMS designed in the last 20 years features automated initialization. I wonder if they were having GPS issues.
Re: "Initial Position" Error (Score:1)
Isn't ATSB rx like $20
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Assuming you mean ADS-B, you can build a capable receiver for around $150 [stratux.me], but you won't be putting that on a commercial aircraft. An FAA or ICAO equivalent certified ADS-B in/out transceiver will cost you a few thousand dollars.
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every INS and FMS designed in the last 20 years features automated initialization. I wonder if they were having GPS issues.
The automated part would not include aligning the inertial, only origin/destination, route and winds. The aircraft has GPS and it should have given them several warnings but the short taxi out may not have given enough time for them to display.
From the report: "The aircraft-generated post-flight report indicated that faults associated with failure of GPS integrity checks occurred 14 and 9 minutes prior to take-off. These failures were the result of the positional error and occurred while the aircraft was b
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Sounds reasonable.
Care to try for why it can't fly on instruments?
Sure, I'll give that a try. How about: you can't fly on instruments if your instruments don't know where the airplane is.
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From the report: "Once ADIRUs 1 and 3 were selected OFF, the captain's primary flight display (PFD) lost all information except accurate airspeed and vertical speed, and the captains ND displayed the GPS PRIMARY LOST, HD
Varig Flight 254 (Score:2)
Varig Flight 254 was a Boeing 737-241, c/n 21006/398, registration PP-VMK, on a scheduled passenger flight from São Paulo, Brazil, to Belém, Pará, Brazil, with several intermediate stopovers, on 3 September 1989. Prior to takeoff from Marabá, Pará, towards the final destination, the crew entered an incorrect heading into the flight computer. Instead of flying towards its destination,
complicated (Score:5, Interesting)
The omission of a trailing zero digit in the manual entry of longitude during system initialization caused serious autopilot/navigation problems that were not resolved by automated cross-checks that should've caught it. (Error #1)
Then, as a result of trying to fix/diagnose the problem on the fly, the flight display/instruments were put into a failure/safe mode where only visual flight conditions could be handled (Error #2).
It turned out ok in this case (just a diversion), but if the weather had been poor or other combinations of conditions existed, it could've easily gone wrong. Very interesting...
Complicated systems need user-friendly confirmatio (Score:3)
This is one of the reasons I still advocate doing navigation in nautical miles instead of km. One nautical mile is def
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You plug in all the numbers for your flight path. It should then display a world map with your flight path overlaid
This in fact was accomplished but the process only displays the route in map mode that does not include a aircraft symbol. The route wasn't the problem, the initial position was. One crosscheck they missed was route distance which would have been off considerably.
This is one of the reasons I still advocate doing navigation in nautical miles instead of km.
In aviation, nautical miles are the only standard. Kilometers are never used. Unfortunately, meters are still used in some parts of the world for altitude assignments.
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but if the weather had been poor
The weather was poor, hence the diversion. But really this is a good example of noticing something is wrong on the fly, ending up in a degraded state and then initiating a well controlled emergency procedure complete with risk assessment that determined the airport they departed from was too risky to allow for a landing.
There's as many successes in this story as failures.
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I didn't say that the errors aren't bad, just that this is a good example of emergency procedures gone right.
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The only "successes" were a properly functioning ATC system and luck.
Luck doesn't land planes with degraded flight controls. Mind you the thing you claim is "only" successes also put all passengers and an intact aircraft back on the ground safety with little more than a delay getting to the destination. The success story here is that fall-backs work remarkably well.
The resolution, once airborne, was a simple one- update the inertial position to actual position- this can be done manually.
With the benefit of hindsight all solutions are simple.
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Luck doesn't land planes with degraded flight controls.
Luck allows a crew that followed one error and multiple omissions with another even more grievous error in an attempt to correct the first (when they certainly should have known better) to have a suitable divert, VMC on top, and capable air traffic controllers sufficient to effect a successful landing.
With the benefit of hindsight all solutions are simple.
Hindsight for this crew would show they executed the wrong checklist and did it incorrectly to boot. To wit: rather than turn off ADRs as called for, the F/O turned off the ADIRS. Hindsight would not show they
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That's wonderfully easy to say from the comfort of your chair.
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Recalls Varig Flight 254 https://en.wikipedia.org/wiki/... [wikipedia.org]
"This misinterpretation changed the general direction north (27) to west (270)."
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Sounds familiar... (Score:2, Funny)
So are they former or future Slashdot editors?
Our robotic overlords (Score:2, Insightful)
checks article Yup, Airbus.
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This is kind of a false idea since a Boeing has the exact same error potential. I was on a flight one time where a navigator messed up the whole inertial reference system and we lost all positional awareness (just like in this article). We didn't get "lost" because I navigated by other means. However, it was on a Boeing airplane. Airbus and Boeing, and while we're at it: Embraer, Sukhoi, Canadair, etc. have the same mode of failure in their navigation systems.
The Airbus is highly automated but it is ver
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checks article Yup, Airbus.
Nice selective quoting.
What it actually said was "The aircraft's systems would not allow the plane to be flown in instrument conditions". This basically says the autopilot refused to kick in due to weather conditions and threw controls back to the pilots. The pilots didn't want to land in Sydney due to the aforementioned weather conditions and diverted to the nearest major airport... which was Melbourne.
So Yep, Airbus... did it right.
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What it actually said was "The aircraft's systems would not allow the plane to be flown in instrument conditions".
From the report: "The FO stated that, in the absence of any ECAM or STATUS messages his initial reaction was to reference the UNRELIABLE AIRSPEED INDICATION checklist in the quick reference handbook (QRH).
Turns out they did to themselves. The aircraft was fine, just positionally lost. There was no failure of aircraft systems, rather a series of procedural errors that led to the loss of aircraft capabilities.
A map would have been nice (Score:3)
http://www.gcmap.com/featured/... [gcmap.com]
It would have been nice to see a map in the news article to give some idea to those reading it unfamiliar with the area just how big of a "blunder" this was. From the Great Circle Mapper website I linked to above we see that KUL is about 4000 miles from SYD, and SYD is less than 500 miles from MEL. Given the typical cruising speed of a jetliner they were in the air for perhaps not much more than an hour on a flight that would have lasted 8 or 9 hours. Since they knew right away something was wrong I doubt they were flying much longer than that, maybe 3 hours. If they were flying much longer than that I suspect they would have landed much further from either SYD or MEL, or we'd be reading about a plane lost at sea.
The article makes a big deal about "landing in the wrong country" which I suppose is a big deal if you take off in the USA, headed for Canada, but end up in India. Much less of a deal if you take off from USA while headed for Canada but a technical problem means you have to land back in USA.