A B737-800 flight crew used improper fuel balance procedures and created a 1200 pound imbal.

Attributes
ACN	704774
Time
Date	200607
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ehf.vortac
State Reference	CA
Altitude	msl single value : 38000
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	704774
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	704776
Events
Anomaly	non adherence : company policies non adherence : published procedure
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

I inadvertently used the center tank fuel procedures of the B737-700/-900 on the B737-800. I failed to monitor the fuel balance after the center fuel tank was empty and with the xfeed open; a 1200 pound imbal occurred before I was aware of my mistake. I am now more aware of the proper center tank fuel use procedure for the B737-800 and will monitor it more closely. Supplemental information from acn 704776: I was the PNF. Had been heads-down for some time (paperwork; housekeeping; charts; etc) when captain mentioned that we had developed a fuel imbal. Need to be more careful about not letting non-flying chores interfere with my monitoring duties.

Original NASA ASRS Text

Title: A B737-800 FLT CREW USED IMPROPER FUEL BAL PROCS AND CREATED A 1200 LB IMBAL.

Narrative: I INADVERTENTLY USED THE CTR TANK FUEL PROCS OF THE B737-700/-900 ON THE B737-800. I FAILED TO MONITOR THE FUEL BAL AFTER THE CTR FUEL TANK WAS EMPTY AND WITH THE XFEED OPEN; A 1200 LB IMBAL OCCURRED BEFORE I WAS AWARE OF MY MISTAKE. I AM NOW MORE AWARE OF THE PROPER CTR TANK FUEL USE PROC FOR THE B737-800 AND WILL MONITOR IT MORE CLOSELY. SUPPLEMENTAL INFO FROM ACN 704776: I WAS THE PNF. HAD BEEN HEADS-DOWN FOR SOME TIME (PAPERWORK; HOUSEKEEPING; CHARTS; ETC) WHEN CAPT MENTIONED THAT WE HAD DEVELOPED A FUEL IMBAL. NEED TO BE MORE CAREFUL ABOUT NOT LETTING NON-FLYING CHORES INTERFERE WITH MY MONITORING DUTIES.

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.