Narrative:

The practice of running these aircraft with the fuel gauges deferred renders all VNAV functions unusable (a significant flight planning tool when considering fuel burns; WX deviations; rertes; and reserves. When this situation is added to thunderstorm WX (almost every day) it makes flight planning en route more difficult and time consuming. As an alternative flight planning tool; dispatch has historically been able to provide timely flight plans to the cockpit in the case of ATC rertes. This capability is not particularly effective with multiple short deviations for en route WX. Also; it seems that dispatch personnel are less able to perform timely flight plan uploads in recent months. A secondary method of recalculating fuel burns when rertes are necessary is to use the 'fuel used' readout from the engine panel and then do the math -- not always practical in short-term decision making with minimal fuel. There seems to be 2 obvious remedies: 1) fix the fuel indicating system. 2) add fuel to provide a catch-all buffer. There is an obvious lack of action regarding option #1. Contrary to most of the operational efficiency themes recently emphasized at air carrier; this scenario leaves the captain with little choice but to add fuel on any leg that might require even slight deviations. The longer the flight segment; the greater the need for a buffer. Additionally; take the flight planning tools that VNAV and a quick scan of the fuel quantity indicators away during another; unrelated irregular operation; and safety (options) is degraded even further.

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Original NASA ASRS Text

Title: B737-300 PLT IS CONCERNED WITH DISPATCHING THE ACFT WITH A FUEL QUANTITY INDICATOR INOP.

Narrative: THE PRACTICE OF RUNNING THESE ACFT WITH THE FUEL GAUGES DEFERRED RENDERS ALL VNAV FUNCTIONS UNUSABLE (A SIGNIFICANT FLT PLANNING TOOL WHEN CONSIDERING FUEL BURNS; WX DEVS; RERTES; AND RESERVES. WHEN THIS SITUATION IS ADDED TO TSTM WX (ALMOST EVERY DAY) IT MAKES FLT PLANNING ENRTE MORE DIFFICULT AND TIME CONSUMING. AS AN ALTERNATIVE FLT PLANNING TOOL; DISPATCH HAS HISTORICALLY BEEN ABLE TO PROVIDE TIMELY FLT PLANS TO THE COCKPIT IN THE CASE OF ATC RERTES. THIS CAPABILITY IS NOT PARTICULARLY EFFECTIVE WITH MULTIPLE SHORT DEVS FOR ENRTE WX. ALSO; IT SEEMS THAT DISPATCH PERSONNEL ARE LESS ABLE TO PERFORM TIMELY FLT PLAN UPLOADS IN RECENT MONTHS. A SECONDARY METHOD OF RECALCULATING FUEL BURNS WHEN RERTES ARE NECESSARY IS TO USE THE 'FUEL USED' READOUT FROM THE ENG PANEL AND THEN DO THE MATH -- NOT ALWAYS PRACTICAL IN SHORT-TERM DECISION MAKING WITH MINIMAL FUEL. THERE SEEMS TO BE 2 OBVIOUS REMEDIES: 1) FIX THE FUEL INDICATING SYS. 2) ADD FUEL TO PROVIDE A CATCH-ALL BUFFER. THERE IS AN OBVIOUS LACK OF ACTION REGARDING OPTION #1. CONTRARY TO MOST OF THE OPERATIONAL EFFICIENCY THEMES RECENTLY EMPHASIZED AT ACR; THIS SCENARIO LEAVES THE CAPT WITH LITTLE CHOICE BUT TO ADD FUEL ON ANY LEG THAT MIGHT REQUIRE EVEN SLIGHT DEVS. THE LONGER THE FLT SEGMENT; THE GREATER THE NEED FOR A BUFFER. ADDITIONALLY; TAKE THE FLT PLANNING TOOLS THAT VNAV AND A QUICK SCAN OF THE FUEL QUANTITY INDICATORS AWAY DURING ANOTHER; UNRELATED IRREGULAR OP; AND SAFETY (OPTIONS) IS DEGRADED EVEN FURTHER.

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.