Controller and pilot report a runway incursion that happened due to communication; leading to a near...

Attributes
ACN	1218911
Time
Date	201411
Local Time Of Day	1801-2400
Place
Locale Reference	ISP.Airport
State Reference	NY
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Route In Use	None
Flight Plan	VFR
Aircraft 2
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	None
Flight Plan	VFR
Person 1
Function	Local Ground
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 13
Person 2
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Private
Experience	Flight Crew Last 90 Days 15 Flight Crew Total 2000 Flight Crew Type 1000
Events
Anomaly	Conflict NMAC Deviation - Procedural Clearance Deviation - Track / Heading All Types Ground Incursion Runway

Narrative:

Aircraft X asked to taxi to runway 24 full length; issued: 'aircraft X taxi to runway 24 via alpha; sierra; B4; cross runway 33L join taxiway echo. Stay to your right for opposite direction small aircraft inbound to the ramp.' aircraft X responded 'you want me to do my run-up on A1?' I said 'negative!' and then repeated the taxi instructions issued before; very slowly. Aircraft X responded 'roger.' at this time I cleared another aircraft for take-off from the mid-field intersection; advising him the prior touch & go would be in right traffic. I then cleared another aircraft to land on runway 24 at which point a small aircraft on taxiway south saw aircraft X enter runway 24 and announced it on the frequency. I observed aircraft X had not followed his instructions and proceeded straight out via A1 and turned right onto runway 24. Aircraft X veered to the right when he observed the small aircraft departure opposite direction. The small aircraft also veered to the right and passed aircraft X at an altitude of approximately 300 feet. Aircraft X was advised to exit the runway and was issued a brasher warning.even if ground had been open; I believe this event would have occurred.

Original NASA ASRS Text

Title: Controller and pilot report a runway incursion that happened due to communication; leading to a NMAC with departing traffic.

Narrative: Aircraft X asked to taxi to runway 24 full length; issued: 'Aircraft X taxi to runway 24 via alpha; sierra; B4; cross RWY 33L join taxiway echo. Stay to your right for opposite direction small aircraft inbound to the ramp.' Aircraft X responded 'You want me to do my run-up on A1?' I said 'Negative!' and then repeated the taxi instructions issued before; very slowly. Aircraft X responded 'Roger.' At this time I cleared another aircraft for take-off from the mid-field intersection; advising him the prior touch & go would be in right traffic. I then cleared another aircraft to land on runway 24 at which point a small aircraft on taxiway S saw Aircraft X enter runway 24 and announced it on the frequency. I observed Aircraft X had not followed his instructions and proceeded straight out via A1 and turned right onto runway 24. Aircraft X veered to the right when he observed the small aircraft departure opposite direction. The small aircraft also veered to the right and passed Aircraft X at an altitude of approximately 300 feet. Aircraft X was advised to exit the runway and was issued a Brasher warning.Even if ground had been open; I believe this event would have occurred.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Controller and pilot report a runway incursion that happened due to communication; leading to a near midair collision with departing traffic.