A B757 FMS database was reported as 'corrupt.' technician deferred the FMS database as inoperative.

Attributes
ACN	708540
Time
Date	200608
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	708540
Person 2
Affiliation	company : air carrier
Function	other personnel other
Events
Anomaly	aircraft equipment problem : critical maintenance problem : non compliance with mel non adherence : published procedure non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : fms display other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : manuals performance deficiency : logbook entry performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Aircraft Environmental Factor Maintenance Human Performance Chart Or Publication
Primary Problem	Maintenance Human Performance

Narrative:

Aircraft X came to gate with PIREP stating the navigation database dated aug/xa/06 and aug/xy/06 was corrupt. I called maintenance controller for guidance. Maintenance controller services suggested placarding the navigation databases per MEL. I interpreted the placard to cover an inoperative for corruption database to be the same as an inoperative for out-of-date; as both conditions would require manual inputs of data into the FMS. I presumed that this was what mr X was also thinking since the flight crews regard an 'out-of-date' database condition to be an inoperative database; just as a 'corrupt' database is considered to be an inoperative database. Mr X called me on wednesday morning. He now believes that he may have advised me incorrectly on the deferral. I still think that the basic reasoning for deferral was sound; but wish to report it. I have verified that the databases have already been updated on aircraft X. In the future; I will press for more discussion of items that are not completely clear between technical service and me. The non-stop work assignments from the start of shift; with multiple distrs of radio and phone conversations in the office while working on the deferral near departure time; interfered with communication and understanding between technical service and me. This caused us to assume 'corrupt' inoperative to be the same as 'out-of-date' inoperative.

Original NASA ASRS Text

Title: A B757 FMS DATABASE WAS RPTED AS 'CORRUPT.' TECHNICIAN DEFERRED THE FMS DATABASE AS INOP.

Narrative: ACFT X CAME TO GATE WITH PIREP STATING THE NAV DATABASE DATED AUG/XA/06 AND AUG/XY/06 WAS CORRUPT. I CALLED MAINT CTLR FOR GUIDANCE. MAINT CTLR SVCS SUGGESTED PLACARDING THE NAV DATABASES PER MEL. I INTERPED THE PLACARD TO COVER AN INOP FOR CORRUPTION DATABASE TO BE THE SAME AS AN INOP FOR OUT-OF-DATE; AS BOTH CONDITIONS WOULD REQUIRE MANUAL INPUTS OF DATA INTO THE FMS. I PRESUMED THAT THIS WAS WHAT MR X WAS ALSO THINKING SINCE THE FLT CREWS REGARD AN 'OUT-OF-DATE' DATABASE CONDITION TO BE AN INOP DATABASE; JUST AS A 'CORRUPT' DATABASE IS CONSIDERED TO BE AN INOP DATABASE. MR X CALLED ME ON WEDNESDAY MORNING. HE NOW BELIEVES THAT HE MAY HAVE ADVISED ME INCORRECTLY ON THE DEFERRAL. I STILL THINK THAT THE BASIC REASONING FOR DEFERRAL WAS SOUND; BUT WISH TO RPT IT. I HAVE VERIFIED THAT THE DATABASES HAVE ALREADY BEEN UPDATED ON ACFT X. IN THE FUTURE; I WILL PRESS FOR MORE DISCUSSION OF ITEMS THAT ARE NOT COMPLETELY CLR BTWN TECHNICAL SVC AND ME. THE NON-STOP WORK ASSIGNMENTS FROM THE START OF SHIFT; WITH MULTIPLE DISTRS OF RADIO AND PHONE CONVERSATIONS IN THE OFFICE WHILE WORKING ON THE DEFERRAL NEAR DEP TIME; INTERFERED WITH COM AND UNDERSTANDING BTWN TECHNICAL SVC AND ME. THIS CAUSED US TO ASSUME 'CORRUPT' INOP TO BE THE SAME AS 'OUT-OF-DATE' INOP.

Data retrieved from NASA's ASRS site as of January 2009 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.