A B757 crew entered an incorrect FMC zero fuel weight for a de-rated takeoff.

Attributes
ACN	702846
Time
Date	200607
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mhr.airport
State Reference	CA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : parked
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 35 flight time total : 18000 flight time type : 757
ASRS Report	702846
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : published procedure non adherence : company policies
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Entered wrong zero fuel weight. 123.6 was entered instead of 163.6. We de-rated with wrong takeoff weight card. Mistake was caught during cruise climb from FL370 to FL410. I was filling out weight and balance sheet while first officer copied clearance. I then closed cargo door while first officer entered zero fuel weight. I did not back up first officer on entry. The mistake was missed by my multitasking instead of doing one thing at a time. I fly this route often; and I think I became lax in my procedures.

Original NASA ASRS Text

Title: A B757 CREW ENTERED AN INCORRECT FMC ZERO FUEL WT FOR A DE-RATED TKOF.

Narrative: ENTERED WRONG ZERO FUEL WT. 123.6 WAS ENTERED INSTEAD OF 163.6. WE DE-RATED WITH WRONG TKOF WT CARD. MISTAKE WAS CAUGHT DURING CRUISE CLB FROM FL370 TO FL410. I WAS FILLING OUT WT AND BAL SHEET WHILE FO COPIED CLRNC. I THEN CLOSED CARGO DOOR WHILE FO ENTERED ZERO FUEL WT. I DID NOT BACK UP FO ON ENTRY. THE MISTAKE WAS MISSED BY MY MULTITASKING INSTEAD OF DOING ONE THING AT A TIME. I FLY THIS RTE OFTEN; AND I THINK I BECAME LAX IN MY PROCS.

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.