Narrative:

On arrival, I was met by a mechanic who informed me he was investigating the possibility that ZZZ maintenance had inadvertently misprogrammed the digital electronic control units on this aircraft using the wrong software and that this may have caused minor operational problems on the previous leg we had flown, (both eecs, electronic engine control system, going to 'soft mode' on engine start). He stated that if this was the case, we had operated an unairworthy aircraft for 2 legs. At this time I do not know as an absolute fact that an unairworthy operation occurred and will add that there is no way that I am aware of that a pilot could check the currency of a buried software item such as this. The mechanic also stated that if the digital electronic control units were indeed misprogrammed, air carrier X would be self-disclosing via maintenance as soon as possible. For the record, my first officer had already left the jetbridge area and as such was not privy to the conversation I had with the mechanic.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B737 WAS FLOWN 2 LEGS WHEN THE CAPT WAS ADVISED THE DIGITAL ELECTRONIC CTL UNIT WAS PROGRAMMED WITH THE WRONG SOFTWARE.

Narrative: ON ARR, I WAS MET BY A MECH WHO INFORMED ME HE WAS INVESTIGATING THE POSSIBILITY THAT ZZZ MAINT HAD INADVERTENTLY MISPROGRAMMED THE DIGITAL ELECTRONIC CTL UNITS ON THIS ACFT USING THE WRONG SOFTWARE AND THAT THIS MAY HAVE CAUSED MINOR OPERATIONAL PROBS ON THE PREVIOUS LEG WE HAD FLOWN, (BOTH EECS, ELECTRONIC ENG CTL SYS, GOING TO 'SOFT MODE' ON ENG START). HE STATED THAT IF THIS WAS THE CASE, WE HAD OPERATED AN UNAIRWORTHY ACFT FOR 2 LEGS. AT THIS TIME I DO NOT KNOW AS AN ABSOLUTE FACT THAT AN UNAIRWORTHY OP OCCURRED AND WILL ADD THAT THERE IS NO WAY THAT I AM AWARE OF THAT A PLT COULD CHK THE CURRENCY OF A BURIED SOFTWARE ITEM SUCH AS THIS. THE MECH ALSO STATED THAT IF THE DIGITAL ELECTRONIC CTL UNITS WERE INDEED MISPROGRAMMED, ACR X WOULD BE SELF-DISCLOSING VIA MAINT ASAP. FOR THE RECORD, MY FO HAD ALREADY LEFT THE JETBRIDGE AREA AND AS SUCH WAS NOT PRIVY TO THE CONVERSATION I HAD WITH THE MECH.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.