MULTIPLE RWY OP INTERSECTING RWYS LTT X HAD NMAC LTSS FROM Y. SYS ERROR.

Narrative

SUDDEN INFLUX OF SMALL ACFT TO HPN HAD TWR CTLR VERY BUSY. LANDED ACR ON RWY 34; DEPARTED COMMUTER RWY 34 AND EXTENDED DOWNWIND 2-3 SMALL ACFT FOR RWY 29. CLRED US INTO POS TO HOLD; ACKNOWLEDGED. 15-20 SECONDS LATER CLRED X FOR IMMEDIATE TKOF. FULL PWR APPLIED; APR ARMED; COPLT CALLING AIRSPDS AND INSTS; CAPT OUTSIDE FOR DIRECTIONAL CTL. A STANDARD; ROUTINE TKOF. AT APPROX 100 KTS; ACCELERATING AND APCHING RWY INTXN WITH RWY 29; I NOTICED CHEROKEE LNDG PROBABLE TOUCHDOWN AT INTXN OR BEYOND. TWR NOTICED EVENT AT ABOUT SAME TIME AND ORDERED GAR FOR CHEROKEE. HIS REACTION WAS TO STOP RATE OF DSCNT; BUT PROBABLY WASN'T CERTAIN IT WAS FOR HIM UNTIL TWR ORDERED GAR AGAIN. I HELD NOSE OF ACFT ON THE RWY UNTIL VR PLUS 15 OR SO. AND ROTATED LATE. IT WAS VERY CLOSE. IF WE HAD ROTATED ON TARGET SPD WE WOULD HAVE HIT HIM. I BELIEVE WHEN TWR CTLR CLRED 2 ACFT TO THE NUMBERS OF RWY 29 THEN CLRED US INTO POS HE MAY HAVE LOST TRACK OF ACFT Y PLUS CLRED US FOR IMMEDIATE TKOF THINKING #2 ACFT WAS THE NEXT TO LAND; PERHAPS LOSING SIGHT OF ACFT Y IN TREES AND LIGHT. WOULD EMPHASIZE ATTN TO DUTIES IN TWR CAB -- NO DISTRS! AND VIGILANCE BY ALL WHEN MULTIPLE RWYS IN USE.