Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Airbus A320 Fly by wire corrupted by radiation in flight

viewfromthewing.com

Post reply on HN
Print view View original

51–60 of 74 posts

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#51

Post by userbinator »

croes wrote: post #47
thisislife2 wrote: post #46

I can understand why this would be priority for Airbus even without the incident of a flight losing altitude - recently read that a major philosophical difference between Airbus and Boeing is that Airbus prioritises the safety of the Aircraft through controls (hardware and software) where as Boeing believes a human should always be the final decision maker and be able to over ride any control. An Airbus rarely allows…

Didn’t workout with the Boeing 737 Max, did it?

That was basically the first Boeing that went in the Airbus direction.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#52

Post by trebligdivad »

RealityVoid wrote: post #49
trebligdivad wrote: post #45

Earlier quoted context omitted.

Where did you see that it didn't have ECC?

"As noted in section 3.5.2, the CPU module on units 4167 and 4122 did not incorporate EDAC, nor was it required by the aircraft manufacturer’s specification" It was apparently added in a later HW revision "The LTN-101 ADIRU’s CPU module was later redesigned to reduce costs and to include error detection and correction (EDAC). EDAC is used for detecting and correcting single-bit errors in RAM chips to give protection…

Thanks; hmm but that means the version with EDAC has been in use since 2002, so is less likely related to todays update? (hth did they design stuff without protection back upto that point?)

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#53

Post by RealityVoid »

trebligdivad wrote: post #52
RealityVoid wrote: post #49

Earlier quoted context omitted.

"As noted in section 3.5.2, the CPU module on units 4167 and 4122 did not incorporate EDAC, nor was it required by the aircraft manufacturer’s specification" It was apparently added in a later HW revision "The LTN-101 ADIRU’s CPU module was later redesigned to reduce costs and to include error detection and correction (EDAC). EDAC is used for detecting and correcting single-bit errors in RAM chips to give protection…

Thanks; hmm but that means the version with EDAC has been in use since 2002, so is less likely related to todays update? (hth did they design stuff without protection back upto that point?)

It's not _only_ that, it's also the fact that the failure mitigation was not catching it, so even if they "fix" the random spikes issue, they still need to consider the "what if" issue if the thing _still_ happens. My money is that they will mitigate this:

"There was a limitation in the algorithm used by the A330/A340 flight control primary computers for processing angle of attack (AOA) data. This limitation meant that, in a very specific situation, multiple AOA spikes from only one of the three air data inertial reference units could result in a nose-down elevator command. [Significant safety issue]"

It's the only one marked "Significant safety issue" so my money is on that.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#54

Post by lxgr »

userbinator wrote: post #51
croes wrote: post #47

Earlier quoted context omitted.

Didn’t workout with the Boeing 737 Max, did it?

That was basically the first Boeing that went in the Airbus direction.

Crucially, while trying to convince everyone that it’s basically the same old 737 to save on pilot retraining costs, nevermind the significantly larger engines.

Airbus is much more transparent about its automation. Pilots even learn about the procedure to fly an A320 with a complete fly-by-wire outage using only mechanical emergency elevator controls and differential thrust.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#55

Post by thuridas »

userbinator wrote: post #51
croes wrote: post #47

Earlier quoted context omitted.

Didn’t workout with the Boeing 737 Max, did it?

That was basically the first Boeing that went in the Airbus direction.

That wasn't just automating... That was hiding the features from the manuals to avoid having to re train the flight crews.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#56

Post by lxgr »

SteveNuts wrote: post #20
lysace wrote: post #8

So the patch will be physical, I imagine. ("Apply this very expensive special tape from (e.g.) 3M here and here.")

I believe most A320s can do OTA software updates (including dowgrades)

OTA? That sounds extremely implausible.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#58

Post by ashleyn »

userbinator wrote: post #6

https://en.wikipedia.org/wiki/Single-event_upset Apparently it has happened to an Airbus once before.

Why do I get the feeling both of these are a diagnosis of exclusion, and there's not particularly any hard evidence that radiation is causing these uncommanded manoeuvres? How unlikely is it for Airbus models specifically to be vulnerable to radiation-induced data corruption twice in almost twenty years? Are there similar incidents recorded for Boeing jets?

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#59

Post by inferiorhuman »

userbinator wrote: post #51
croes wrote: post #47

Earlier quoted context omitted.

Didn’t workout with the Boeing 737 Max, did it?

That was basically the first Boeing that went in the Airbus direction.

No it wasn't. See also: MD-11, 737NG, 777, 787.

Re: Airbus A320 Fly by wire corrupted by radiation in flight

#60

Post by berti »

trebligdivad wrote: post #52
RealityVoid wrote: post #49

Earlier quoted context omitted.

"As noted in section 3.5.2, the CPU module on units 4167 and 4122 did not incorporate EDAC, nor was it required by the aircraft manufacturer’s specification" It was apparently added in a later HW revision "The LTN-101 ADIRU’s CPU module was later redesigned to reduce costs and to include error detection and correction (EDAC). EDAC is used for detecting and correcting single-bit errors in RAM chips to give protection…

Thanks; hmm but that means the version with EDAC has been in use since 2002, so is less likely related to todays update? (hth did they design stuff without protection back upto that point?)

That's applicable for one specific model of ADIRU (basically determines where the aircraft is in 3d space in terms of position, rotation, velocities, and accelerations) from a single manufacturer (Litton). These aircraft have dozens of computers for different functions, many of them with multiple manufacturer options. There are at least 4 different ADIRU makers that airlines have been able to specify at different times including the Litton.

The ELACs (controlling the elevator and aileron actuators according to the demands computed by other functions) are made by Thales specifically for this aircraft type and probably have a quite different design.

Post reply on HN