SMT PLT HAD DOUBLE ENG FAILURE.

Narrative

ACFT WAS AEROCOMMANDER 680. I PERSONALLY FUELED THE ACFT TO CAPACITY BEFORE THE FLT. THE POH STATES 223 GALS USEABLE FUEL. AFTER A 4 1/2 HR FLT; WITH A CALCULATED BURN OF 153 GALS (AT 17 GPH/ENG) PLUS 25 GALS FOR CLB (10000 FT); BOTH ENGS QUIT OUTSIDE THE MARKER WHILE BEING VECTORED TO INTERCEPT THE ILS. I SWITCHED TO THE OUTBOARD TANKS; AND PWR WAS RESTORED FOR 10-15 SECONDS. AGAIN I SWITCHED BACK TO THE MAIN TANK; BUT WITHOUT RESULT. AT THAT TIME; THE MAIN TANK FUEL GAUGE READ 27 GALS. AT THAT POINT I CALLED CRITICAL FUEL TO THE TWR; AND WAS CLRED TO LAND STRAIGHT IN RWY 35. IT WAS OBVIOUS THAT I WOULD NOT MAKE THE RWY WITH BOTH ENGS WINDMILLING; SO I FEATHERED BOTH PROPS; SET BEST GLIDE; AND DEAD-STICKED IN. I LOWERED THE GEAR ON SHORT FINAL; AND BEGAN TO PUMP THE FLAPS DOWN TO SLOW DOWN; AND RESTORE HYD PRESSURE FOR THE BRAKES AND STEERING. THE TOUCHDOWN WAS UNEVENTFUL. I EXITED THE RWY TO THE L ON THE HIGH SPD; CLRED THE PARALLEL TXWY; AND ROLLED TO A STOP ON THE W RAMP PARKING AREA. THE ACFT WAS THEN TOPPED OFF TO CAPACITY. FUEL: 187.4 GALS. SUSPECTED CAUSE: THE CAPACITY OF THE ACFT'S TOTAL TANKAGE IS SUBSTANTIALLY LESS THAN 223 GALS (MISSET BLADDERS?). CONTRIBUTING FACTOR: 25 GAL ERROR IN MAIN TANK GAUGE. THE ACTUAL CAPACITY OF THE ACFT WILL BE MEASURED. THE MAIN TANK GAUGE WILL BE CHKED/RECALIBRATED. ATC HANDLING OF THE INCIDENT WAS SUPERB-TIMELY; PROFESSIONAL; EFFICIENT. THE TWR CAB CALLED THE FBO AFTERWARDS; AND I HAD A TELEPHONE CHAT WITH THE CTLR. HE WAS SO HELPFUL AS TO DIG UP THIS NASA FORM FOR ME. GREAT GUY; GREAT SYS. MY PERFORMANCE WAS ADEQUATE; HOWEVER; SOMEWHERE IN THE MEL TRAINING SYLLABUS; SOME MENTION SHOULD BE MADE OF THE TECHNIQUE AND FEATHERING BOTH ENGS TO EXTEND THE GLIDE IN A DIRE EMER. I GUESS IF I HADN'T SEEN IT DONE BEFORE IN A STRIKE COMMANDER; I WOULDN'T HAVE THOUGHT TO DO IT. IT SAVED THE AIRPLANE; AND MAYBE ME TOO.