B737 flight crew reports receiving a final weights message that is 13;456 pounds less than planned w...

Attributes
ACN	1291694
Time
Date	201508
Local Time Of Day	0001-0600
Place
Locale Reference	ORD.Airport
State Reference	IL
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 13300 Flight Crew Type 5339
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 106 Flight Crew Type 7549
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Procedural Weight And Balance

Narrative:

I arrived at the gate and put in numbers from the flight plan. The fueler was still putting fuel on the airplane. I did not get the planned final weights at that time since the fuel was not loaded. I did load the zero fuel weight and numbers but I did not obtain a planned final weights. I did the walk around and came back; the fuel was still not loaded. When fuel was loaded the fuel slip was received and the gallons were added to the ACARS initialization page and from there a planned takeoff weight was obtained. We taxied out and went through our new procedures; starting an engine and taxiing in chicago. We managed to get everything done in sequence. The final weights were loaded and were executed; then an accept prompt appeared without v speeds. This was executed and we obtained v speeds and put those into to v-speed page.in flight when trying to retrieve landing data we got a standardized computerized aircraft performance (scap) error. I thought it was an issue with the fuel slip but after we reviewed our paperwork we realized the takeoff weight was not accurate. We calculated our actual weight and used that for our landing speeds.

Original NASA ASRS Text

Title: B737 flight crew reports receiving a final weights message that is 13;456 pounds less than planned which goes undetected. V speeds are calculated and entered and the flight departs. Upon requesting landing data prior to descent a Standard Computerized Aircraft Performance (SCAP) error message was received and the landing weight is corrected in the FMC.

Narrative: I arrived at the gate and put in numbers from the flight plan. The fueler was still putting fuel on the airplane. I did not get the planned final weights at that time since the fuel was not loaded. I did load the zero fuel weight and numbers but I did not obtain a planned final weights. I did the walk around and came back; the fuel was still not loaded. When fuel was loaded the fuel slip was received and the gallons were added to the ACARS initialization page and from there a planned takeoff weight was obtained. We taxied out and went through our new procedures; starting an engine and taxiing in Chicago. We managed to get everything done in sequence. The final weights were loaded and were executed; then an accept prompt appeared without v speeds. This was executed and we obtained v speeds and put those into to v-speed page.In flight when trying to retrieve landing data we got a Standardized Computerized Aircraft Performance (SCAP) error. I thought it was an issue with the fuel slip but after we reviewed our paperwork we realized the takeoff weight was not accurate. We calculated our actual weight and used that for our landing speeds.

Data retrieved from NASA's ASRS site 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.