B737 captain discovered enroute that he may have departed with less than required fuel on an ETOPS f...

Narrative:

We departed with the required fuel on the release. At cruise our fuel calculations agreed with the FMC in that we had sufficient fuel to complete the flight. The fuel at landing was over 6000 pounds; which was above the minimum but less than usual for the ETOPS flights that we are used too. With the switch to the new flight planning software and fuel savings initiative with the company we thought that was just a new procedure. At the critical point we were within a 1000 pounds of the flight plan and continued. A turn around would have us landing with the same fuel at both ends of the flight plan. We also had sufficient fuel to continue just not the amount we were used too. I received an email from safety representatives for the airline indicating there was a problem with the software. The new fight planning software and the complexity of ETOPS fuel planning created a 'perfect storm' in which a shortage of required fuel could be masked without detection in the limited amount of time in a normal sequence of events in an ETOPS flight. I discussed the event with the first officer and we both concluded that we had enough fuel but should have questioned the amount of fuel on the flight plan in more detail. In the future I will take more time to ensure the fuel requirements on the flight plan add up to equal the amount on the release.

Original NASA ASRS Text

Title: B737 Captain discovered enroute that he may have departed with less than required fuel on an ETOPS flight. There was a difference between flight plan fuel and release fuel apparently caused by glitches in new flight planning software.

Narrative: We departed with the required fuel on the release. At cruise our fuel calculations agreed with the FMC in that we had sufficient fuel to complete the flight. The fuel at landing was over 6000 LBS; which was above the minimum but less than usual for the ETOPS flights that we are used too. With the switch to the new flight planning software and fuel savings initiative with the company we thought that was just a new procedure. At the critical point we were within a 1000 LBS of the flight plan and continued. A turn around would have us landing with the same fuel at both ends of the flight plan. We also had sufficient fuel to continue just not the amount we were used too. I received an email from safety representatives for the airline indicating there was a problem with the software. The new fight planning software and the complexity of ETOPS fuel planning created a 'Perfect Storm' in which a shortage of required fuel could be masked without detection in the limited amount of time in a normal sequence of events in an ETOPS flight. I discussed the event with the First Officer and we both concluded that we had enough fuel but should have questioned the amount of fuel on the flight plan in more detail. In the future I will take more time to ensure the fuel requirements on the flight plan add up to equal the amount on the release.

Data retrieved from NASA's ASRS site as of April 2012 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	842403
Time
Date	200907
Local Time Of Day	1201-1800
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Procedural FAR Deviation - Procedural Published Material / Policy Inflight Event / Encounter Fuel Issue

B737 captain discovered enroute that he may have departed with less than required fuel on an ETOPS flight. There was a difference between flight plan fuel and release fuel apparently caused by glitches in new flight planning software.