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A400M Airbus Flier crashed because of software issues

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Re: A400M Airbus Flier crashed because of software issues

#51

Post by JoeAltmaier »

DougWebb wrote: post #46
mhandley wrote: post #33

Earlier quoted context omitted.

The A400M that crashed was on its first test flight, so unless they've done something very odd with versioning, it's unlikely that all its ECUs had older firmware than planes that already shipped. Besides, with aircraft, all changes are logged with a ton of paperwork, so they shouldn't need to check the aircraft to know what firmware they're running.

It doesn't seem so unlikely to me. Supply chains are long and parts are bought in bulk. I think it's likely that the parts for the ECUs, including boards with chips containing the older firmware, are warehoused where the ECUs are assembled. The ECUs are probably then bought in bulk and warehoused where the planes are assembled. The paperwork for the plane probably includes the ECU serial numbers, but it probably does…

I think you underestimate the tracking done in commercial airplane manufacture. I believe the source of every rivet is well-known. And how many planes do they make? Many parts are likely manufactured as needed, one at a time.

Re: A400M Airbus Flier crashed because of software issues

#52

Post by userbinator »

alandarev wrote: post #18

Software contractor for Airbus and Rolls-royce here. All safety critical software (every piece of code ran on-board is safety critical the least) in aerospace needs to pass the DO-178 standard [1]. That is far more serious than standard unit tests you are used to in node.js applications. Generally speaking, to develop a piece of code under that standard it takes 20% of time to write the code, and 80% to testing, and…

The target catastrophic failure rate there is 1 in a billion hours, which doesn't seem all that high to me... there are over 100000 flights a day[1], and the average length of one is well over an hour, so in one day all the aircraft in the world have accumulated a total of over 2.4 million hours in operation. If each flight was only an hour long, that's 417 days to 1 billion total hours, and if the failure rate really was 1 in a billion we'd expect to see one of these happen at almost yearly rates.

The actual failure rate of software to this standard seems to be at least two orders of magnitude higher.

[1] http://www.garfors.com/2014/06/100000-flights-day.html

Re: A400M Airbus Flier crashed because of software issues

#53

Post by mason240 »

DougWebb wrote: post #49
mrmondo wrote: post #37

I wonder if this is the time to argue that it may be worth open sourcing the controlling software for hackers to start criticising and contributing pull requests to. I'm willing to bet that the competence of the collective community far outweighs that of those specially trained to write the software at present. What is there to lose by opening up the software to criticism other than better aviation safety? We know th…

What is there to lose? 0-Day attacks. Knowledge about bugs in aviation software is potentially more valuable to people who wish to do harm than to the people who would fix the bugs, so there's a concern that someone who finds a bug will sell that info rather than let the maintainers know about it. The other problem is that the maintainers have to be set up to handle a potential avalanche of comments, criticisms, ques…

Realistically, how could someone exploit a 0-day in a aviation software?

Re: A400M Airbus Flier crashed because of software issues

#54

Post by DougWebb »

mason240 wrote: post #53
DougWebb wrote: post #49

Earlier quoted context omitted.

What is there to lose? 0-Day attacks. Knowledge about bugs in aviation software is potentially more valuable to people who wish to do harm than to the people who would fix the bugs, so there's a concern that someone who finds a bug will sell that info rather than let the maintainers know about it. The other problem is that the maintainers have to be set up to handle a potential avalanche of comments, criticisms, ques…

Realistically, how could someone exploit a 0-day in a aviation software?

I don't know. I wouldn't want to find out. But more realistically, a good bug that's worth a lot of money will be subtle and hard to find, which means it may be around long enough to be exploitable.

Re: A400M Airbus Flier crashed because of software issues

#55

Post by [deleted] »

alandarev wrote: post #18

Software contractor for Airbus and Rolls-royce here. All safety critical software (every piece of code ran on-board is safety critical the least) in aerospace needs to pass the DO-178 standard [1]. That is far more serious than standard unit tests you are used to in node.js applications. Generally speaking, to develop a piece of code under that standard it takes 20% of time to write the code, and 80% to testing, and…

[deleted]

Re: A400M Airbus Flier crashed because of software issues

#56

Post by tjbiddle »

lamby wrote: post #47
castell wrote: post #42

Earlier quoted context omitted.

Which programming language is commonly used there? Ada, C, C++, JOVIAL, Asm?

With that kind of coding-to-testing-and-documentation ratio, does it even matter?

Then to add to it, what are tests written in?

Re: A400M Airbus Flier crashed because of software issues

#57

Post by UnoriginalGuy »

lamby wrote: post #47
castell wrote: post #42

Earlier quoted context omitted.

Which programming language is commonly used there? Ada, C, C++, JOVIAL, Asm?

With that kind of coding-to-testing-and-documentation ratio, does it even matter?

Yes. Some languages are better at scoping than others. Functional languages are easier to test because they have more confined scope.

Re: A400M Airbus Flier crashed because of software issues

#58

Post by fransan »

lucaspiller wrote: post #8
bhaak wrote: post #4

There are not many details about why exactly the three engines stopped working and it's not yet officially announced. This article has been written with "information Spiegel Online received". Two translated quotes: "The investigation yield a clear result: Shortly after the lift-off of the test machine, the computers send conflicting commands to the three engines which then powered off." "Soon after the crash, experts…

> So, not much information why the computers sent conflicting commands and also why the engines power down in such a situation. I think shutting down the engines is probably the safest option when this sort of thing happens. You could argue they should stay in the present setting, but what would happen if one engine were at 0% and another 100%? Most aircraft are pretty good at gliding even without power, and I'd assu…

> I think shutting down the engines is probably the safest option when this sort of thing happens. You could argue they should stay in the present setting, but...

Shutting down an engine should always be a decision made by the pilot not a machine IMO. A pilot might prefer to blow out an engine if that gives him enough ( even a couple of seconds matter in this situation ) time to reach a save landing spot or avoid an obstacle.

> what would happen if one engine were at 0% and another 100%?

Pilots are train in this situation all the time and is part of the syllabus for a multi-engine rating. Basically the plane would try to turn to the side that the engine failed. Pilot will use opposite ruder and aileron to compensate while cutting back power in the good engine to just enough you can keep altitude if possible.

> Most aircraft are pretty good at gliding even without power, and I'd assume a deadstick landing is part of the pilots training.

So happen here too. The crew tried tried a dead-stick landing in a field when they realized the could not make the airport. Unfortunately the hit a High Power pole and the plane catch fire.

One of the crew members lost in the accident was a friend of my father. My condolence to the families of those who lost their live that day.

Re: A400M Airbus Flier crashed because of software issues

#59

Post by sleeping_pills »

mrmondo wrote: post #37

I wonder if this is the time to argue that it may be worth open sourcing the controlling software for hackers to start criticising and contributing pull requests to. I'm willing to bet that the competence of the collective community far outweighs that of those specially trained to write the software at present. What is there to lose by opening up the software to criticism other than better aviation safety? We know th…

While I agree with your statement that open sourcing code can help with improving it's quality, how exactly do you envision (paraphrasing) "hackers contributing pull requests" to code that controls engines on an airplane? Here you have an extremely specialized codebase which can perhaps be understood by a tiny group of professionals and it can actually be tested by an absolutely vanishingly small group of individuals under special circumstances. I don't think "hackers" could even begin to make useful critique of this kind of software, let alone contribute pull requests to it.

Re: A400M Airbus Flier crashed because of software issues

#60

Post by TeeWEE »

alandarev wrote: post #18

Software contractor for Airbus and Rolls-royce here. All safety critical software (every piece of code ran on-board is safety critical the least) in aerospace needs to pass the DO-178 standard [1]. That is far more serious than standard unit tests you are used to in node.js applications. Generally speaking, to develop a piece of code under that standard it takes 20% of time to write the code, and 80% to testing, and…

I'm quite baffled at the fact that this standard does not include formal verification of the software models used.

Formal verification and state space analysis can prove that the software "model" will not fail. State space exploration of the actual implementation is actually often not feasible due to the enourmous amount of states.

So my question: Are you doing formal analysis of the software models/designs? I know they are using it in software used in space crafts / nuclear power plants.

Reference: - http://ti.arc.nasa.gov/m/profile/dimitra/euromicro-share.pdf - http://javapathfinder.sourceforge.net/

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