AS11296 -- Hijacked?

Steven Bellovin smb at cs.columbia.edu
Sat Oct 2 22:47:01 UTC 2010


On Oct 1, 2010, at 7:00 51PM, Owen DeLong wrote:

> 
> On Oct 1, 2010, at 2:31 PM, George Bonser wrote:
> 
>> 
>> 
>>> -----Original Message-----
>>> From: wherrin at gmail.com 
>>> Herrin
>>> Sent: Friday, October 01, 2010 2:27 PM
>>> To: George Bonser
>>> Cc: Christopher Morrow; nanog at nanog.org
>>> Subject: Re: AS11296 -- Hijacked?
>>> 
>>> 
>>> Death by IP address?
>>> 
>>> -Bill
>> 
>> Quite possible if one is using it to distribute a virus. RE: Spanair
>> flight JK-5022
>> 
>> http://www.monstersandcritics.com/news/europe/news/article_1578877.php/C
>> omputer-viruses-may-have-contributed-to-Spanish-2008-plane-crash
>> 
>> 
> 
> http://aircrewbuzz.com/2008/10/officials-release-preliminary-report-on.html
> 
> A more recent Interim report:
> 
> http://www.fomento.es/NR/rdonlyres/AADDBF93-690C-4186-983C-8D897F09EAA5/75736/2008_032_A_INTERINO_01_ENG.pdf
> 
> The crew apparently skipped the step where they were supposed to deploy
> the slats/flaps prior to takeoff.
> 
> Additionally, the warning system on the aircraft which should have alerted
> the crew to the failure to extend the flaps/slats also failed to sound.
> 
> A computer virus may have had a small contribution to the failure to detect
> the warning system failure in the maintenance process, but, it did not cause
> the accident.
> 
> The accident is clearly the result of pilot error, specifically the failure to
> properly configure the aircraft for takeoff and failure to take remedial
> action upon activation of the stall warning system during the initial
> climb.
> 
There's more to the story than that.  There was a problem with a sensor -- the heater for it was running when the plane was on the ground, which it shouldn't do.  The mechanic couldn't reproduce the problem; since there was no icing likely and the heater was only needed if there was icing, the pilot flipped the breaker to disable it.  (The virus-infected computer was the one that should have been used to log two previous reports of that same heater problem, but no one even tried entering the reports until after the crash, so the virus wasn't at all the problem.)  Because of the distractions -- the return to the gate, the co-pilot making a call to cancel dinner planes, a third person in the cockpit, the pilots indeed forgot to set the flaps -- and just breezed through the checklist item (which they did recite) rather than actually paying attention to it.

However...  the accident investigators learned that in almost all previous instances, worldwide, of that heater problem, the cause was a failed relay in the "I'm on the ground" circuit.  That same relay was used to activate the Takeoff Configuration Warning System -- which didn't alert the pilots to the flaps problem because the relay failed again after the plane left the gate for the second time.  In other words, a crucial safety system had a single point of failure -- and that failure also contributed to the distraction that led to the pre-takeoff pilot error.


		--Steve Bellovin, http://www.cs.columbia.edu/~smb









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