LATAM upset SYD-AKL Mon 11 Mar
I don't think it was quite as you suggest, but with reported loss of primary displays and reported loss of control it is instructive to note that in the anticipated situation for which FAA-2015-0936 Interim Airworthiness Directive that at a predictable point in time the 4-off Generator Control Units could simultaneously go into Fail-safe mode and deprive the aircraft of AC electrical power, it "could result in loss of control of the airplane" and could occur regardless of flight phase That related to exceeding a 248 day powered period, so the AD instructed that power was removed at least every 120 days.
Regarding the 120 day maintenance action interval, note that in 2020, FAA-2020-0205 (not an Interim AD) was raised due to counter/timers associated with the Common Core System, that could affect data integrity after 51 days, and a power-down repeat interval of 25 days was specified in B787–81205–SB420045–00, Issue 2.
There may well be other mechanisms that have similar symptoms, so
In this case, they should have a lot more info from the aircraft, although if the CCS was interrupted, the Enhanced Airborne Flight Recorder might have some missing ARINC 664 data.
The immediate take away is that whatever did occur, the point in the flight and the actions taken recovered the situation, which 787 pilots will hopefully learn more about soon.
Wot cood posiblie go rong?
It's as if the writing of and functioning of software in aircraft systems isn't the subject of standards. If only software engineers could anticipate the remote possibility that the software they design will be running continuously in hardware that doesn't take a coffee break.
Last edited by Lead Balloon; 12th Mar 2024 at 08:01.
The New Zealand Transport Accident Investigation Commission is merely acting on a request for assistance from Chilean civil aviation authorities who have jurisdiction over investigating this incident due to the airliner being in international airspace when it occurred and the airliner being on the Chilean civil register. However, because NZ was the nearest country and that is where the airliner landed and is now grounded, I guess it is only natural for Chilean civil aviation authorities to ask TAIC to secure all evidence until they can get their own investigators to Auckland. Under the Transport Accident Investigation Commission's charter, they are required to render assistance to foreign civil aviation and maritime authorities if requested. For those of you outside NZ, TAIC's mandate is to investigate, on a no blame basis, accidents and serious operating incidents in the aviation, maritime and railway transport modes. Their primary purpose is not to point the finger, but to get to the bottom of what actually occurred, any relevant background information, what can be learned from the findings, and how such an occurrence can be prevented from happening in the future. Any legal prosecutions in NZ come not from TAIC, but from other government agencies and regulatory bodies, such as NZ Civil Aviation Authority, NZ Maritime Authority, Waka Kotahi NZ Land Transport Agency, or NZ Police.
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I'm no fan of Boeing. The 787 is a piece of garbage. The single point of failure behind the MAX accidents is abhorent design philosphy. No argument from me there. I just dont get why Airbus seems to get a freep ass when the only reason that 330 didn't spear into the ground precisely as the Max did was luck. At least the Max pilots had a memory item specifically designed to address the trim runaway in the 737. No such procedure in the 330 back in 2008, unless I"m mistaken?
Anyway, let the Boeing bashing continue. Any manufacturer that makes me sit there and twist the heading bug whilst in managed lateral navigation for 10 hours at a time deserves all the criticism it gets.
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System redundancy at Airbus at least means that: redundancy. Different systems. At Boeing, it's misinterpreted to mean "more of the same".
Airbus's ELACs are truly redundant Motorola and Intel systems at the hardware level, and programmed in different languages, by different teams, precisely to provide redundancy at the code/microprocessor level. You might get a hint of why that matters right about when all three GCUs fail at the same time in a 787 because of a coding error.
See here for more detail: Why so many computers for flight controls in A320?
I'm also noting that Boeing did another booboo with their integrated IRSs in the 787 that can no longer operate independently of GNSS. That's (really) bad news when you're being spoofed.
The 787 (and the MAX) are piss poor designs that should never have been approved to fly. Can't wait for one of the first few 787's that came off the line to get a lightning strike in the wing. They're an accident waiting to happen. Which is only acceptable in which world? Right. Accounting world. And that's who runs that company these days.
Shame.
Airbus's ELACs are truly redundant Motorola and Intel systems at the hardware level, and programmed in different languages, by different teams, precisely to provide redundancy at the code/microprocessor level. You might get a hint of why that matters right about when all three GCUs fail at the same time in a 787 because of a coding error.
See here for more detail: Why so many computers for flight controls in A320?
I'm also noting that Boeing did another booboo with their integrated IRSs in the 787 that can no longer operate independently of GNSS. That's (really) bad news when you're being spoofed.
The 787 (and the MAX) are piss poor designs that should never have been approved to fly. Can't wait for one of the first few 787's that came off the line to get a lightning strike in the wing. They're an accident waiting to happen. Which is only acceptable in which world? Right. Accounting world. And that's who runs that company these days.
Shame.
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More speculation
Concerning: 2. What is programmed to occur to the pitch flight control surface positions (primarily elevator and THS) when electrical power is lost...when electrical power is restored..?
One possible scenario could be a pilot trying to maintain attitude during the outage by control input - unsuccessfully - then power being restored while a (possibly full deflection) input is still being applied...
One possible scenario could be a pilot trying to maintain attitude during the outage by control input - unsuccessfully - then power being restored while a (possibly full deflection) input is still being applied...
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For those interested in the FAA’s directive regarding depowering the CDN/aircraft, the link below will explain it somewhat.
https://ioactive.com/reverse-enginee...ess-directive/
https://ioactive.com/reverse-enginee...ess-directive/
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I don't think it was quite as you suggest, but with reported loss of primary displays and reported loss of control it is instructive to note that in the anticipated situation for which FAA-2015-0936 Interim Airworthiness Directive that at a predictable point in time the 4-off Generator Control Units could simultaneously go into Fail-safe mode and deprive the aircraft of AC electrical power, it "could result in loss of control of the airplane" and could occur regardless of flight phase That related to exceeding a 248 day powered period, so the AD instructed that power was removed at least every 120 days.
Regarding the 120 day maintenance action interval, note that in 2020, FAA-2020-0205 (not an Interim AD) was raised due to counter/timers associated with the Common Core System, that could affect data integrity after 51 days, and a power-down repeat interval of 25 days was specified in B787–81205–SB420045–00, Issue 2.
Sounds like they are running Windows OS. At one of my customers, the boss bought an accounting system running on windows, using SQL Server als Database. Three years ago they were forced to add a POS (PointOfSales) module issuing the cryptographically linked cash-receipts as per government anti-fraud-laws.
Since then, every 3 weeks +/- one week one of the 10 cashier systems would lock up (while cash customer is waiting).
Manufacturer "looked into it" didn't find anything to fix and installed a Sunday morning reboot of application and database server,
problem "solved the Microsoft way".
The merchandise handling system (the one I wrote) runs 24/7 on an ORACLE database on Linux (yes, open source). Current uptime is 300 days (e.g. since last hardware failure). In my 35 years of experience I cannot imagine any problem on Linux that would "require" a server reboot to clear.
One of the biggest Austrian Banks I do consulting for is running slightly north of 300 ORACLE Databases on Linux, including multi terabyte trading systems,
and not one of them "needs" periodical reboots.
Lesson to learn:
any system that needs regular reboots to keep working contains abysmal software not thorougly tested.
If after start, cruise and landing an FMC accumulates "debris" data that needs to be cleared by reboot the software is crap,
not thorougly cleaning up data traces after completing the "landing" phase.
That could be because the designing engineers were idiots, or because cost cutting mangement did not provide them with ample resources for thoroughly testing before claiming "read for business".
You may guess what my experience in that field is.
hint:
I've witnessed a european airlive got bust because clueless management went from hierarchical database system to relational database (e.g. total redesign) w/o having their own engineers lead in that process and impatiantly declaring "transition done" when it wasn't.
Last edited by Reely340; 12th Mar 2024 at 11:49.
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https://www.aviationtoday.com/2015/0...-software-fix/
Avionics Today 05-05-2015] Boeing will provide a software update later this year to address an issue that causes the 787 Dreamliner’s Generator Control Units (GCUs) to simultaneously go into failsafe mode after being powered continuously for 248 days. The FAA has issued an Airworthiness Directive (AD) calling for 787 operators to address the glitch, which is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power, the AD states.
Boeing 787-9 Dreamliner. Photo: Boeing
According to the FAA’s directive, when a 787 has been powered continuously for 248 days, it can lose all Alternating Current (AC) electrical power due to the GCU software anomaly. The directive requires a repetitive maintenance task for electrical power deactivation on 787s.
“This condition is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power. We are issuing this AD to prevent loss of all AC electrical power, which could result in loss of control of the airplane,” the FAA’s directive states.
Boeing plans on issuing a software update for the 787 by the fourth quarter of 2015 to address the issue.
Originally, Boeing observed this GCU software issue during lab testing after eight months of continuous power. After discovering the issue, Boeing recommended the AD’s mandated actions to operators on April 19, 2015.
“It is important to note this issue was observed in the lab only after eight months of continuous power, which would be highly unusual. All operators have already completed the cycle off-cycle on fix, and they know how often they need to do it in the future until the software update arrives later this year,” a spokesman for Boeing told Avionics Magazine.
Most importantly, the AD addresses an anomaly that would only occur under extremely rare conditions within normal airline fleet schedules. By performing a power-off/power-on cycle, operators eliminate the risk that all six generators aboard the aircraft would lose power at the same time.
In the directive, the FAA indicates that in the occurrence that the four main GCUs associated with the engine mounted generators were powered up at the same time, the four GCUs would all fail at the same time. This would result in a “loss of all AC electrical power regardless of flight phase,” the AD states.
Boeing 787 fleet maintenance records indicate that all in-service airplanes have already performed a power-off/power-on cycle within their ongoing maintenance schedules. Operators that have a definitive record of a power cycle within the last 120 days do not need to take any immediate action, Boeing has confirmed. A total of 28 aircraft in the U.S. registry are affected by the AD, which has also determined that the cost of the electrical power deactivation is one work hour at $85 per deactivation cycle.
Since it first entered service in 2011, Boeing has delivered 258 total 787s, and has a backlog of 847 undelivered Dreamliners.
Avionics Today 05-05-2015] Boeing will provide a software update later this year to address an issue that causes the 787 Dreamliner’s Generator Control Units (GCUs) to simultaneously go into failsafe mode after being powered continuously for 248 days. The FAA has issued an Airworthiness Directive (AD) calling for 787 operators to address the glitch, which is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power, the AD states.
Boeing 787-9 Dreamliner. Photo: Boeing
According to the FAA’s directive, when a 787 has been powered continuously for 248 days, it can lose all Alternating Current (AC) electrical power due to the GCU software anomaly. The directive requires a repetitive maintenance task for electrical power deactivation on 787s.
“This condition is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power. We are issuing this AD to prevent loss of all AC electrical power, which could result in loss of control of the airplane,” the FAA’s directive states.
Boeing plans on issuing a software update for the 787 by the fourth quarter of 2015 to address the issue.
Originally, Boeing observed this GCU software issue during lab testing after eight months of continuous power. After discovering the issue, Boeing recommended the AD’s mandated actions to operators on April 19, 2015.
“It is important to note this issue was observed in the lab only after eight months of continuous power, which would be highly unusual. All operators have already completed the cycle off-cycle on fix, and they know how often they need to do it in the future until the software update arrives later this year,” a spokesman for Boeing told Avionics Magazine.
Most importantly, the AD addresses an anomaly that would only occur under extremely rare conditions within normal airline fleet schedules. By performing a power-off/power-on cycle, operators eliminate the risk that all six generators aboard the aircraft would lose power at the same time.
In the directive, the FAA indicates that in the occurrence that the four main GCUs associated with the engine mounted generators were powered up at the same time, the four GCUs would all fail at the same time. This would result in a “loss of all AC electrical power regardless of flight phase,” the AD states.
Boeing 787 fleet maintenance records indicate that all in-service airplanes have already performed a power-off/power-on cycle within their ongoing maintenance schedules. Operators that have a definitive record of a power cycle within the last 120 days do not need to take any immediate action, Boeing has confirmed. A total of 28 aircraft in the U.S. registry are affected by the AD, which has also determined that the cost of the electrical power deactivation is one work hour at $85 per deactivation cycle.
Since it first entered service in 2011, Boeing has delivered 258 total 787s, and has a backlog of 847 undelivered Dreamliners.
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So is the system so stupid that it doesn’t even warn of the impending need to power off if it hasn’t been done by the correct interval?
Why does it let the aircraft take off if it will decide to shut everything down half way through the flight?
Why does it let the aircraft take off if it will decide to shut everything down half way through the flight?
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https://www.aviationtoday.com/2015/0...-software-fix/
Avionics Today 05-05-2015] Boeing will provide a software update later this year to address an issue that causes the 787 Dreamliner’s Generator Control Units (GCUs) to simultaneously go into failsafe mode after being powered continuously for 248 days. The FAA has issued an Airworthiness Directive (AD) calling for 787 operators to address the glitch, which is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power, the AD states.
Avionics Today 05-05-2015] Boeing will provide a software update later this year to address an issue that causes the 787 Dreamliner’s Generator Control Units (GCUs) to simultaneously go into failsafe mode after being powered continuously for 248 days. The FAA has issued an Airworthiness Directive (AD) calling for 787 operators to address the glitch, which is caused by a software counter internal to the GCUs that will overflow after 248 days of continuous power, the AD states.
HP and Dell managed to sell a lot of Enterprise class SSDs (solid state disks) made by SanDisk, where the firmware programmers managed to implement an operating hours counter that causes the thing to irrevocably brick, as soon as it reaches 32768 (2 to the power of 15) hours.
https://www.thestack.technology/ssd-...hours-sandisk/
In an instant all your terabytes of data on the SSDs - while still "stored" - cannot accessed anymore.
And the unit cannot be patched, as it doesn't talk to the outside world anymore.
Now, if you installed a couple of them in a server, for redundancy for instance, the tiny variations of the internal clocks
will have them die within for example 10 hours of each other, just like the EC135 accident at night over Edinburgh when
the second engine (twin engine redundancy, we've heard it) went silent some 32 seconds after the first one,
while the POH claims the differently sizes tanks should(!) cause a 4 minute delay between fuel starvations.
Last edited by Reely340; 12th Mar 2024 at 13:24.
https://www.industryweek.com/supply-...hour-engineers
Remember some big brains who didn’t anticipate Y2K.
It doesn't look ahead. It doesn't anticipate. It doesn't know that it will have to shut down. It just reaches a particular timed point at which (if I understand correctly) the software falls over.
That's assuming of course that it is a software issue. Which given that a 'fix' was apparently made available several years ago is by no means nailed on.
Boeing engineering? The same outsourced low cost software engineers?
https://www.industryweek.com/supply-...hour-engineers
Remember some big brains who didn’t anticipate Y2K.
https://www.industryweek.com/supply-...hour-engineers
Remember some big brains who didn’t anticipate Y2K.
But it was the transactions logs of database which are pivotal for being able to recover the database in case of media failures.
Luckily one of us overpair european dinosaurs discovered that mess and took counter action.
One would think management immediately cancelled that subcontract and employed a couple more local pros, being thankfor "lesson learned w/o damage".
But we all can guess who still is allowed and payed to mess with central, business critical banking databases.
Too cheap to get rid of, seems to be management's motto.
Is it ever likely that an aircraft would remain electrically powered up continuously for 248 days? Possible, certainly but likely?
And when was the last time that LATAM 787 was totally dark?
And when was the last time that LATAM 787 was totally dark?
AO-2024-002
Boeing 787-9, in-flight disturbance over Tasman Sea, 11 March 2024
Status
Current
Occurrence Date
11 Mar 2024
Jurisdiction
Overseas
TAIC is providing support for an investigation by Chilean investigation authority, the Dirección General de Aeronáutica Civil into an incident involving a Boeing 787 aircraft in international air space on its way to New Zealand.
The reported circumstances were that on 11 March 2024, a Boeing 787-9 passenger aircraft, registration CC-BGG, was traveling from Sydney, Australia, to Auckland, New Zealand. The aircraft was operated by LATAM Airlines. About 250 nautical miles from Auckland, it encountered a ‘technical problem’ and a resulting ‘strong movement’ in which around 50 passengers, including cabin crew, were injured. The aircraft landed in Auckland safely. No fatalities were reported.
Chile, as the State of Registry, is investigating this incident and has requested New Zealand’s assistance. TAIC is gathering evidence on behalf of Chile. TAIC will not produce a report for this inquiry. This is a responsibility of Chile authorities.
Boeing 787-9, in-flight disturbance over Tasman Sea, 11 March 2024
Status
Current
Occurrence Date
11 Mar 2024
Jurisdiction
Overseas
TAIC is providing support for an investigation by Chilean investigation authority, the Dirección General de Aeronáutica Civil into an incident involving a Boeing 787 aircraft in international air space on its way to New Zealand.
The reported circumstances were that on 11 March 2024, a Boeing 787-9 passenger aircraft, registration CC-BGG, was traveling from Sydney, Australia, to Auckland, New Zealand. The aircraft was operated by LATAM Airlines. About 250 nautical miles from Auckland, it encountered a ‘technical problem’ and a resulting ‘strong movement’ in which around 50 passengers, including cabin crew, were injured. The aircraft landed in Auckland safely. No fatalities were reported.
Chile, as the State of Registry, is investigating this incident and has requested New Zealand’s assistance. TAIC is gathering evidence on behalf of Chile. TAIC will not produce a report for this inquiry. This is a responsibility of Chile authorities.