LTSS BTWN SMA AND COMMUTER ACFT. PLTDEV.

Narrative

AT APPROX XA38 I DEPARTED SMA X IFR SUNOL 3 DEP. LCL POS COMBINED WORKING MODERATE TO HVY TFC MOSTLY DEPS. X WAS 1 1/2 MI OFF DEP END RWY 30. I THEN TAXIED COMMUTER Y INTO POS RWY 30L AND HOLD. PLT ACKNOWLEDGED INSTRUCTIONS. ACFT Y WAS ALSO A SUNOL 3 DEP AND I HAD TO WAIT ABOUT 2 MORE MINS BEFORE ENOUGH SEPARATION WOULD EXIST BTWN X AND Y. HOWEVER; I WAS ALSO DEPARTING ACFT FROM 2 OTHER RWYS. AT XA40 I OBSERVED ACFT Y AT TAXIWAY G (5000 FT DOWN RWY 30L) NOSE UP ATTITUDE. I THEN LOOKED AT MY COORDINATOR AND ASKED WHO WAS DEPARTING AND AFTER THAT WAS ESTABLISHED; DID I CLR ACFT Y FOR TKOF? I IMMEDIATELY SCANNED THE RADAR FOR SMA X WHILE COORDINATOR WAS ON LANDLINE WITH BAY TRYING TO COORDINATE WHAT TO DO. I REALIZED THAT A DECISION WAS IMMINENT TO AVOID COLLISION. BOTH ACFT WERE GOING TO ENTER IFR CONDITIONS WITHIN SECONDS. ACFT Y WAS ALSO 50-70 KTS FASTER. I OBSERVED X LEAVING 1500 FT 2 1/2 MI OFF DEP END. ACFT Y WAS 1 MI BEHIND AND I TURNED Y TO 360 DEG. I ISSUED X AS TFC. Y RPTED X IN SIGHT. BAY GAVE APPROVAL FOR 360 DEG FOR SUNOL. BAY TURNED X BEHIND Y. I USUALLY STATE A REASON FOR THE HOLD WHEN NOT OBVIOUS. THIS TIME I DID NOT. I FELT THAT I TOOK THE MOST APPROPRIATE ACTION WITH REGARD TO TIME CONSTRAINTS. ALSO; ACFT CHARACTERISTICS WERE TAKEN INTO CONSIDERATION. TAPES VERIFIED Y WAS NEVER ISSUED TKOF CLRNC. 360 DEG IS NOT A STANDARD DEP HDG. SHOULD HAVE TURNED ACFT Y L TO 270 DEG OR 140 DEG BUT THEN WOULD HAVE HAD A SYS DEV FOR VIOLATING BAY'S AIRSPACE. RESOLUTION: IF TKOF CLRNCS WILL NOT BE ISSUED FOR MORE THAN 2 MINS; DO NOT PUT ACFT INTO POS ON RWY.