A B767-300 Captain reports encountering a very poorly written and confusing MEL Chapter 73-21-3 and Dispatch Maintenance Procedures (DMP) required for a 'LH ENG FUEL VLV IND LT INOP' deferral. Four Line Mechanics; one Maintenance Controller Supervisor; one Assistant Chief Pilot and two pilots could not agree on whether one step of the procedures applied after each shut-down.

Narrative

FUEL CONTROL ENG VALVE INDICATION SYSTEM. B767-300 aircraft. Reference MEL Chapter 73-21-3; 'LH ENG FUEL VLV IND LT INOP;' deferred October 2010. This report is to bring to light a very poorly written MEL procedure. Step 2 under 'Operations Procedures' states; 'shut down engine using Maintenance Procedures (see associated DMP)'. Looking at the referenced DMP (Dispatch Maintenance Procedures); there are four steps; with the last step having four more sub-steps. Although steps 1-3 are feasible for a [flight] crew to accomplish; step 4 was not intended for a crew to accomplish. Nor was it intended to be accomplished at every [engine] shutdown; but instead; after the initial MEL procedure was accomplished (according to Maintenance). We (four Line Mechanics; one Maintenance Controller Supervisor; one Assistant Chief Pilot (ACP); two Pilots) discussed this MEL prior to startup; and could not come to a unanimous decision. Most of the mechanics believed however that we should not do ANY of the DMP (disregard step 2 of MEL); that this DMP procedure was only to be accomplished with the initial MEL signoff. Another opinion was that we should accomplish steps 1-3 of DMP; but not step 4. All of our training has been that you either do a complete procedure until you reach 'end of procedure'; or you don't do it at all. We are not trained to do partial procedures; and we are not supposed to skip steps. Unfortunately; these seem to be the only two options until the MEL is re-written. Reviewing this MEL procedure and discussing it and making phone calls; resulted in a 10 minute delay pushing-back. As one last safety measure; we asked our Assistant Chief Pilot to make another call to the Maintenance Controller Supervisor to discuss this MEL and get a clear interpretation; and to ACARS us the result through our Dispatcher; so that we could adhere to the MEL when shutting down. (Per the MEL; the startup procedure was normal; so we went ahead and pushed back and started.) Enroute we received an ACARS message that stated: 'MEL 73-21-3 is poorly written. Proceed with normal engine shutdown with no DMP Maintenance Procedure. Per Assistant Chief Pilot.'