AN INSTRUCTIONAL FLT FAILED TO MAINTAIN SEPARATION ON TKOF FROM W29.

Narrative

COMMERCIAL STUDENT IN L SEAT WAS FLYING AIRPLANE. CFI (RPTR) IN R SEAT WAS GIVING INSTRUCTION. TFC USING ARPT WERE ANNOUNCING POS 'IN THE BLIND' ON CTAF. BEECH SIERRA; FIRST IN LINE AWAITING TKOF; ANNOUNCED INTENTIONS; TAXIED ONTO RWY 29; AND BEGAN TKOF ROLL. A PIPER CHEROKEE; ON L BASE; ANNOUNCED TURNING FINAL. PLT OF CARDINAL ANNOUNCED TKOF INTENTIONS; TAXIED ONTO RWY 29; AND BEGAN TKOF ROLL. SIERRA AHEAD OF CARDINAL ABORTED TKOF WITHOUT ANNOUNCING AND EXITED RWY AT FIRST AVAILABLE TXWY. PLT OF CARDINAL CONTINUED TKOF ROLL AND EXECUTED NORMAL TKOF WITHOUT HAVING TO TAKE EVASIVE ACTION OR ABORT TKOF. PIPER CHEROKEE ON FINAL APCH OPTED TO GO AROUND AND ANNOUNCED THIS ON CTAF. AFTER DISCUSSING THE EVENT THAT HAD JUST TRANSPIRED; THE COMMERCIAL STUDENT AND CFI IN THE CARDINAL DECIDED THAT ADEQUATE SEPARATION BTWN THE SIERRA AHEAD AND THE CHEROKEE BEHIND HAD NOT BEEN MAINTAINED. IT WAS DECIDED THAT THE SAFE; PRUDENT ACTION WOULD HAVE BEEN TO WAIT FOR THE SIERRA TO BECOME AIRBORNE AND FOR THE CHEROKEE TO LAND AND EXIT THE RWY. SUPPLEMENTAL INFO FROM ACN 450674: I SHOULD HAVE WAITED FOR THE PLANE TAKING OFF TO REACH CLBOUT ATTITUDE BEFORE I TOOK THE RWY. I ALSO SHOULD HAVE LET THE LNDG ACFT PROCEED WITH THE LNDG AND THEN TAKEN POSSESSION OF THE RWY.