ACR X LANDED ON OCCUPIED RWY AFTER ACR Y ABORTED TKOF. RWY INCURSION.

Narrative

ACR X WAS CLRED TO LAND ON RWY 28R SHORTLY AFTER CONTACTING SFO TWR AT BRIJJ. ACR Y; WDB; WAS THEN CLRED FOR TKOF ON RWY 28R. ACR Y TOOK A LONG TIME TO BEGIN THE TKOF ROLL. MEANWHILE THE CREW BRIEFLY MENTIONED WAKE TURB TECHNIQUES. ON VERY SHORT FINAL; THE CREW LOST TRACK OF THE ACR Y DUE TO IT BEING AT THE FAR END OF THE RWY. JUST AS THE ACFT TOUCHED DOWN; TWR INSTRUCTED ACR X 'GAR.' THE ACR Y HAD ABORTED THE TKOF AND WAS ROLLING OUT AT THE FAR END OF RWY 28R. ACR Y HAD NOT DECLARED AN ABORTED TKOF. AT THIS POINT IT WAS TOO LATE FOR A BALKED LNDG SO THE CAPT SLOWED THE ACFT AND TURNED OFF AT TXWY E. THE LNDG WAS ON CTRLINE AND IN THE TOUCHDOWN ZONE. ON CONTACTING GND CTL; THE CREW WAS INSTRUCTED TO CALL TWR ON THE PHONE. WHEN THE CAPT CALLED; THE TWR SUPVR SAID HE HAD LISTENED TO THE TAPES AND ASKED WHY WE HAD NOT GONE AROUND. THE CAPT SAID THAT THE ACFT WAS ON THE GND WHEN TWR SAID 'GAR' AND TO GAR WOULD HAVE REQUIRED A TOUCH- AND-GO TOWARD AN ACFT ON THE RWY. CONTRIBUTING FACTORS: LIGHT WINDS NOT CLRING EXHAUST SMOKE. WHEN ACR X CREW FIRST SAW ACR Y; ONLY THE TOP HALF OF THE VERT FIN WAS VISIBLE. THE REST OF THE ACFT WAS COMPLETELY OBSCURED.