Myf local controller instructor reported of a runway incursion and ground conflict because of an air...

Attributes
ACN	1362460
Time
Date	201606
Local Time Of Day	1201-1800
Place
Locale Reference	MYF.Tower
State Reference	CA
Environment
Light	Daylight
Aircraft 1
Make Model Name	PA-46 Malibu/Malibu Mirage/Malibu Matrix
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Route In Use	None
Aircraft 2
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	None
Flight Plan	VFR
Person 1
Function	Instructor Local
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 1.5
Events
Anomaly	Conflict Ground Conflict Critical Deviation - Procedural Clearance Ground Incursion Runway

Narrative:

Training in progress on local; I was the ojti. Aircraft X landed runway 28R; and my student instructed aircraft X to exit taxiway foxtrot hold short of runway 28L and remain this frequency. Aircraft X gave an incomplete readback of hold short instructions. My student corrected the pilot and then aircraft X gave a complete and accurate readback of hold short instructions. My student then cleared aircraft Y for takeoff on runway 28L. As I was watching the situation develop; it appeared that aircraft X was getting very close to the runway; at which point I jumped in and canceled the takeoff clearance for aircraft Y twice; to be sure the pilot heard it. As aircraft Y was decelerating; aircraft X was about halfway through crossing runway 28L. Aircraft X was then issued the brasher warning.

Original NASA ASRS Text

Title: MYF Local Controller Instructor reported of a runway incursion and ground conflict because of an aircraft that crossed halfway onto the runway while a departure aircraft was told to stop twice. The crossing aircraft read back hold short instructions.

Narrative: Training in progress on Local; I was the OJTI. Aircraft X landed runway 28R; and my student instructed Aircraft X to exit taxiway Foxtrot hold short of Runway 28L and remain this frequency. Aircraft X gave an incomplete readback of hold short instructions. My student corrected the pilot and then Aircraft X gave a complete and accurate readback of hold short instructions. My student then cleared Aircraft Y for takeoff on runway 28L. As I was watching the situation develop; it appeared that Aircraft X was getting very close to the runway; at which point I jumped in and canceled the takeoff clearance for Aircraft Y twice; to be sure the pilot heard it. As Aircraft Y was decelerating; Aircraft X was about halfway through crossing runway 28L. Aircraft X was then issued the Brasher warning.

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.

Myf local controller instructor reported of a runway incursion and ground conflict because of an aircraft that crossed halfway onto the runway while a departure aircraft was told to stop twice. The crossing aircraft read back hold short instructions.