Narrative:

Left ZZZ, first officer, ramp with 15000 pounds of fuel instead of center wing fuel tank minimum of 17000 pounds. Felt 17000 pound requirement satisfied because the total min fuel requirement on board, dispatch release remarks section stated '17000 pounds or more fuel assured based on 6.56,' and fuel slip showed only 12004 pounds to be loaded into cwt. Also wording of restriction is different than supposed intention. I feel problem was mistake made because 1) new restriction 2) dispatch release remarks intimated 17000 pounds restriction was satisfied. 3) fuel slip dispatch load schedule showed only 12004 pounds to be loaded in cwt. 4) if intention of this directive is to say any time fuel in center wing tank (cwt) is to be used over the course of plane trip from X to Y then minimum of fuel in cwt must be 17000 pounds or more prior to engine start, then the directive is saying something different. The directive says 'if the cwt ovrd/jet pumps are to be selected on during flight, the cwt must contain at least 17000 pounds of fuel prior to engine start.' this is confusing because common english translation of this would be: 'if (only in the following situation) the cwt ovrd/jet pumps are to be selected on (turned on using cockpit electric switch) during flight (while airborne) the cwt must contain at least 17000 pounds of fuel prior to engine start.' this is further conflicted because air carrier's current procedure says if less than 10000 pounds in cwt make takeoff without turning on pumps until after takeoff (airborne), or if more than 10000 pounds, turn on pumps prior to takeoff (and thus no need to turn on pumps in flight). Then second half of this procedure would satisfy procedure and new directive because the 'if the cwt...' pumps are to be selected on during flight would not be the case as pumps would be on prior to flight in this case because our cwt contained 15000 pounds. Additionally in the operating procedures no reference is made to ensuring proper fuel is in cwt or how much is required. The wording in operating procedure #1 makes no mention of a min of 7000 pounds when operating with less than 50000 pounds. This wording would allow my interpertation of the restriction to coexist. If directive is to require 17000 pounds minimum be in cwt prior to engine start any time cwt ovrd/jet pumps will be turned on, then operating instructions should contain language to ensure 17000 pounds in cwt prior to engine start or more particularly prior to turning pumps on in cwt. Not mentioning minimum seems to allow for 2 sits to exist. Callback conversation with reporter revealed the following information: the reporter stated according to the flight planning, this airplane was dispatched in non compliance with the airworthiness directive, as the center tank fuel load was 12004 pounds and not the required 17000 pounds. The reporter said the dispatch release noted the 17000 pounds restriction was satisfied due to having extra fuel in the wing tanks. The reporter stated it was clear the dispatcher did not understand the intent of the airworthiness directive and the reason for the 17000 pounds of fuel in the center tank. The reporter said it is his understanding the fuel pumps if operated must be covered by fuel if used in climb. The reporter stated the company operating procedure states if the center tank pumps are operated prior to takeoff the fuel in center tank must be greater than 10000 pounds. The reporter said the company was advised of the confusion and conflict with this airworthiness directive wording. The reporter stated no answer has been received.

Google
 

Original NASA ASRS Text

Title: A B747-200 SO RPTS CONFUSION AND CONFLICT ON AIRWORTHINESS DIRECTIVE REGARDING CENTER WING TANK FUEL RESTRICTIONS.

Narrative: LEFT ZZZ, FO, RAMP WITH 15000 LBS OF FUEL INSTEAD OF CENTER WING FUEL TANK MINIMUM OF 17000 LBS. FELT 17000 POUND REQUIREMENT SATISFIED BECAUSE THE TOTAL MIN FUEL REQUIREMENT ON BOARD, DISPATCH RELEASE REMARKS SECTION STATED '17000 LBS OR MORE FUEL ASSURED BASED ON 6.56,' AND FUEL SLIP SHOWED ONLY 12004 LBS TO BE LOADED INTO CWT. ALSO WORDING OF RESTRICTION IS DIFFERENT THAN SUPPOSED INTENTION. I FEEL PROBLEM WAS MISTAKE MADE BECAUSE 1) NEW RESTRICTION 2) DISPATCH RELEASE REMARKS INTIMATED 17000 LBS RESTRICTION WAS SATISFIED. 3) FUEL SLIP DISPATCH LOAD SCHEDULE SHOWED ONLY 12004 LBS TO BE LOADED IN CWT. 4) IF INTENTION OF THIS DIRECTIVE IS TO SAY ANY TIME FUEL IN CENTER WING TANK (CWT) IS TO BE USED OVER THE COURSE OF PLANE TRIP FROM X TO Y THEN MINIMUM OF FUEL IN CWT MUST BE 17000 LBS OR MORE PRIOR TO ENG START, THEN THE DIRECTIVE IS SAYING SOMETHING DIFFERENT. THE DIRECTIVE SAYS 'IF THE CWT OVRD/JET PUMPS ARE TO BE SELECTED ON DURING FLT, THE CWT MUST CONTAIN AT LEAST 17000 LBS OF FUEL PRIOR TO ENG START.' THIS IS CONFUSING BECAUSE COMMON ENGLISH TRANSLATION OF THIS WOULD BE: 'IF (ONLY IN THE FOLLOWING SIT) THE CWT OVRD/JET PUMPS ARE TO BE SELECTED ON (TURNED ON USING COCKPIT ELECTRIC SWITCH) DURING FLT (WHILE AIRBORNE) THE CWT MUST CONTAIN AT LEAST 17000 LBS OF FUEL PRIOR TO ENG START.' THIS IS FURTHER CONFLICTED BECAUSE ACR'S CURRENT PROC SAYS IF LESS THAN 10000 LBS IN CWT MAKE TKOF WITHOUT TURNING ON PUMPS UNTIL AFTER TKOF (AIRBORNE), OR IF MORE THAN 10000 LBS, TURN ON PUMPS PRIOR TO TKOF (AND THUS NO NEED TO TURN ON PUMPS IN FLT). THEN SECOND HALF OF THIS PROC WOULD SATISFY PROC AND NEW DIRECTIVE BECAUSE THE 'IF THE CWT...' PUMPS ARE TO BE SELECTED ON DURING FLT WOULD NOT BE THE CASE AS PUMPS WOULD BE ON PRIOR TO FLT IN THIS CASE BECAUSE OUR CWT CONTAINED 15000 LBS. ADDITIONALLY IN THE OPERATING PROCS NO REFERENCE IS MADE TO ENSURING PROPER FUEL IS IN CWT OR HOW MUCH IS REQUIRED. THE WORDING IN OPERATING PROC #1 MAKES NO MENTION OF A MIN OF 7000 LBS WHEN OPERATING WITH LESS THAN 50000 LBS. THIS WORDING WOULD ALLOW MY INTERPERTATION OF THE RESTRICTION TO COEXIST. IF DIRECTIVE IS TO REQUIRE 17000 LBS MINIMUM BE IN CWT PRIOR TO ENG START ANY TIME CWT OVRD/JET PUMPS WILL BE TURNED ON, THEN OPERATING INSTRUCTIONS SHOULD CONTAIN LANGUAGE TO ENSURE 17000 LBS IN CWT PRIOR TO ENG START OR MORE PARTICULARLY PRIOR TO TURNING PUMPS ON IN CWT. NOT MENTIONING MINIMUM SEEMS TO ALLOW FOR 2 SITS TO EXIST. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED ACCORDING TO THE FLT PLANNING, THIS AIRPLANE WAS DISPATCHED IN NON COMPLIANCE WITH THE AIRWORTHINESS DIRECTIVE, AS THE CENTER TANK FUEL LOAD WAS 12004 LBS AND NOT THE REQUIRED 17000 LBS. THE RPTR SAID THE DISPATCH RELEASE NOTED THE 17000 LBS RESTRICTION WAS SATISFIED DUE TO HAVING EXTRA FUEL IN THE WING TANKS. THE RPTR STATED IT WAS CLR THE DISPATCHER DID NOT UNDERSTAND THE INTENT OF THE AIRWORTHINESS DIRECTIVE AND THE REASON FOR THE 17000 LBS OF FUEL IN THE CENTER TANK. THE RPTR SAID IT IS HIS UNDERSTANDING THE FUEL PUMPS IF OPERATED MUST BE COVERED BY FUEL IF USED IN CLB. THE RPTR STATED THE COMPANY OPERATING PROC STATES IF THE CENTER TANK PUMPS ARE OPERATED PRIOR TO TKOF THE FUEL IN CENTER TANK MUST BE GREATER THAN 10000 LBS. THE RPTR SAID THE COMPANY WAS ADVISED OF THE CONFUSION AND CONFLICT WITH THIS AIRWORTHINESS DIRECTIVE WORDING. THE RPTR STATED NO ANSWER HAS BEEN RECEIVED.

Data retrieved from NASA's ASRS site as of July 2007 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.