Sfo tower controller reported a runway incursion that possibly would have been missed if it weren't ...

Attributes
ACN	1715980
Time
Date	201912
Local Time Of Day	0001-0600
Place
Locale Reference	SFO.Tower
State Reference	CA
Aircraft 1
Make Model Name	B777-300
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Route In Use	Other Instrument Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Other Instrument Approach
Flight Plan	IFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 9
Events
Anomaly	Conflict Ground Conflict Critical Ground Incursion Runway

Narrative:

I told aircraft X to hold short of runway 28L. The pilot read back the hold short instructions. At the same time a controller was opening up local assist. Getting his chair; and was getting paper. In the process blocking the view of twy H. Not an issue since I heard the feedback. Aircraft X slowly started to cross 28L. Ground controller said 'he is moving.' I sent aircraft Y around. Told aircraft X to stop. Fabulous team work.hard to say because if local assist had been opened 2 minutes later; I would have seen aircraft X moving sooner. Ground did a great job of notifying me of the situation progressing.

Original NASA ASRS Text

Title: SFO Tower Controller reported a runway incursion that possibly would have been missed if it weren't for the Ground Controller advising the Local Controller.

Narrative: I told Aircraft X to hold short of RWY 28L. The pilot read back the hold short instructions. At the same time a Controller was opening up Local Assist. Getting his chair; and was getting paper. In the process blocking the view of TWY H. Not an issue since I heard the feedback. Aircraft X slowly started to cross 28L. Ground Controller said 'He is moving.' I sent Aircraft Y around. Told Aircraft X to stop. Fabulous team work.Hard to say because if Local Assist had been opened 2 minutes later; I would have seen Aircraft X moving sooner. Ground did a great job of notifying me of the situation progressing.

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.

Sfo tower controller reported a runway incursion that possibly would have been missed if it weren't for the ground controller advising the local controller.