Reports of incorrect FMC performance software installation on B737 aircraft.

Attributes
ACN	435260
Time
Date	199904
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : stl.airport
State Reference	MO
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : stl.tower
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : atp pilot : cfi pilot : commercial
Experience	flight time last 90 days : 200 flight time total : 4000 flight time type : 1000
ASRS Report	435260
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical non adherence : company policies
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	other
Supplementary
Problem Areas	Aircraft Company Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

During preflight, I noticed an unexplainable line item on the FMC/CDU takeoff reference page. Apparently, it was the result of an improper database having been installed. We were later advised that the CDU had been previously installed in a B737-700 and had not been reprogrammed for use in the B737-500 series. Despite the strange line item, the FMC correctly calculated data for us and was independently verified by the onboard performance computer, which is not tied in any way to the FMC. So, despite having a technically improper computer confign, the flts that day were operated safely.

Original NASA ASRS Text

Title: RPTS OF INCORRECT FMC PERFORMANCE SOFTWARE INSTALLATION ON B737 ACFT.

Narrative: DURING PREFLT, I NOTICED AN UNEXPLAINABLE LINE ITEM ON THE FMC/CDU TKOF REF PAGE. APPARENTLY, IT WAS THE RESULT OF AN IMPROPER DATABASE HAVING BEEN INSTALLED. WE WERE LATER ADVISED THAT THE CDU HAD BEEN PREVIOUSLY INSTALLED IN A B737-700 AND HAD NOT BEEN REPROGRAMMED FOR USE IN THE B737-500 SERIES. DESPITE THE STRANGE LINE ITEM, THE FMC CORRECTLY CALCULATED DATA FOR US AND WAS INDEPENDENTLY VERIFIED BY THE ONBOARD PERFORMANCE COMPUTER, WHICH IS NOT TIED IN ANY WAY TO THE FMC. SO, DESPITE HAVING A TECHNICALLY IMPROPER COMPUTER CONFIGN, THE FLTS THAT DAY WERE OPERATED SAFELY.

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.