A B777 with an inoperative APU Start System was MEL'ed using 49-1 for the allowed ten days. Then to continue APU use; MEL 49 03 A was applied which required it to be run during flight.

Narrative

On flight plan saw APU Start System INOP (49 03 A). Got to the aircraft; it was very hot 99+ on temperature inside. Delayed boarding. Maintenance showed up and gets the APU started somehow and began getting the aircraft cool. Well; in log book APU Start System placarded INOP using 49-03 A; which indicates to have APU started at gate and run for entire flight. After talking to dispatch; I asked why not use 49 03 B instead so we don't have to run APU for ten hours. He had already been down that road because if you use 49 03 B it says to then placard APU INOP using 49 01. 49 01 had been used for 10 days and timed out so it could not be used. Under 49 03 you have two ways to go. IS THE APU REQUIRED FOR DISPATCH? At the time I thought it was not required due to flight plan (NON ETOPS); 49 03 B should be used but it couldn't so dispatch required the APU on the flight. Now 49 03 A could be used. The earlier write ups (2) on the APU had been cleared by replacing APU door parts days earlier. Then APU Start System 49 03 A used to placard APU INOP. Safety of flight was never a question. What the problem was is using the MEL in a way that it was not intended to be used. Chief Pilot on call was called. The Director of Maintenance was called. Maintenance Control was called. Nobody really seemed to have a big problem with this operation. So with dispatch requiring the APU; I took the aircraft using 49 03 A and ran APU.