Local controller described a conflict event between a VFR fixed wing aircraft and a VFR helicopter d...

Narrative:

A R44 requested to depart alpha taxiway westbound to turn north and join the highway eastbound. The R44 was instructed by the trainee to depart alpha to the west to join the highway eastbound and was issued traffic on a cessna about to depart the parallel runway to the taxiway in the same direction. C207 was issued traffic on the helicopter departing to the west on the parallel taxiway and then proceeded to begin his takeoff roll. After the cessna departed; he made an early turn over the runway towards the helicopter and again was issued traffic on the helicopter ahead and to his right. He then acknowledged the traffic ahead and began to climb and make an early turn north and above the helicopter. The helicopter was then advised the cessna was turning inside and above him to the northwest and the helicopter pilot acknowledged that he had the cessna in sight. I believe this situation happened due to the cessna making an early turnout when he was instructed that he would have traffic ahead and north of his position turning east. I believe the pilot didn't anticipate the helicopter taking as long as he did in the upwind before his initial turn to the downwind and assumed an early turn out to the north would be ok. I recommend that the trainee take a more proactive approach to the situation and not assume that the pilot would fly his intended course with the helicopter in sight. The situation caused the trainee to have to provide additional traffic calls and to watch the situation closely to ensure proper separation was maintained. The trainee was given multiple scenario fixes to the situation as stopping the cessna as soon as he turns early and instructing him to continue his upwind climb; or to turn the helicopter early to ensure diverging courses are sufficient.

Original NASA ASRS Text

Title: Local Controller described a conflict event between a VFR fixed wing aircraft and a VFR helicopter departing via a parallel taxiway; the reporter noted the fixed wing aircraft over flew the helicopter.

Narrative: A R44 requested to depart Alpha Taxiway westbound to turn north and join the highway eastbound. The R44 was instructed by the trainee to depart Alpha to the west to join the highway eastbound and was issued traffic on a Cessna about to depart the parallel runway to the taxiway in the same direction. C207 was issued traffic on the helicopter departing to the west on the parallel taxiway and then proceeded to begin his takeoff roll. After the Cessna departed; he made an early turn over the runway towards the helicopter and again was issued traffic on the helicopter ahead and to his right. He then acknowledged the traffic ahead and began to climb and make an early turn north and above the helicopter. The helicopter was then advised the Cessna was turning inside and above him to the northwest and the helicopter pilot acknowledged that he had the Cessna in sight. I believe this situation happened due to the Cessna making an early turnout when he was instructed that he would have traffic ahead and north of his position turning east. I believe the pilot didn't anticipate the helicopter taking as long as he did in the upwind before his initial turn to the downwind and assumed an early turn out to the north would be OK. I recommend that the trainee take a more proactive approach to the situation and not assume that the pilot would fly his intended course with the helicopter in sight. The situation caused the trainee to have to provide additional traffic calls and to watch the situation closely to ensure proper separation was maintained. The trainee was given multiple scenario fixes to the situation as stopping the Cessna as soon as he turns early and instructing him to continue his upwind climb; or to turn the helicopter early to ensure diverging courses are sufficient.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1107324
Time
Date	201308
Local Time Of Day	0001-0600
Place
Locale Reference	MRI.Airport
State Reference	AK
Aircraft 1
Make Model Name	Cessna Stationair/Turbo Stationair 7/8
Operating Under FAR Part	Part 91
Flight Phase	Initial Climb
Flight Plan	VFR
Aircraft 2
Make Model Name	Robinson R44
Flight Phase	Initial Climb
Flight Plan	VFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

Local controller described a conflict event between a VFR fixed wing aircraft and a VFR helicopter departing via a parallel taxiway; the reporter noted the fixed wing aircraft over flew the helicopter.