A CRJ200 flight crew determined the FMS zero fuel weight calculations were incorrect by several hund...

Narrative:

Aircraft swap and we met crew who had just flown the aircraft we were receiving. They informed us of a possible problem with the load planning calculations on weight and balance on their previous flights in this aircraft. Therefore; my captain and I thoroughly went through all of the preset numbers in the FMS such as basic operating weight; etc. And confirmed all to be correct. Additionally we did a hand written weight and balance as a precaution. We determined the weights to be different by a few hundred pounds so we therefore used the more conservative and accurate hand written form for our flight. Once at cruise and en route decided to try to determine where the error was coming from. We discovered that the error was in the zero fuel weight but could not exactly figure where. We suspected that the load planning numbers were wrong for the passenger weights somewhere and as it turns out we hear that was the case; specifically section C passenger weights.

Original NASA ASRS Text

Title: A CRJ200 flight crew determined the FMS Zero Fuel Weight calculations were incorrect by several hundred pounds; data determining passenger weights was apparently incorrect.

Narrative: Aircraft swap and we met crew who had just flown the aircraft we were receiving. They informed us of a possible problem with the load planning calculations on weight and balance on their previous flights in this aircraft. Therefore; my Captain and I thoroughly went through all of the preset numbers in the FMS such as Basic Operating Weight; etc. and confirmed all to be correct. Additionally we did a hand written weight and balance as a precaution. We determined the weights to be different by a few hundred pounds so we therefore used the more conservative and accurate hand written form for our flight. Once at cruise and en route decided to try to determine where the error was coming from. We discovered that the error was in the Zero Fuel Weight but could not exactly figure where. We suspected that the load planning numbers were wrong for the passenger weights somewhere and as it turns out we hear that was the case; specifically section C passenger weights.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	997770
Time
Date	201203
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Commercial
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Weight And Balance

A CRJ200 flight crew determined the FMS zero fuel weight calculations were incorrect by several hundred pounds; data determining passenger weights was apparently incorrect.