SA 365 Dauphin 2
Air Traffic Control Fully Certified
Situational Awareness; Confusion; Communication Breakdown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance
Procedure; Human Factors
A Coast Guard AS65 Dauphin called as a rescue wanting to depart E and E13 and depart shoreline north. After all the appropriate coordination had been performed; I cleared him for takeoff and issued 'proceed direct to the shoreline then cleared out of Bravo Airspace as requested.' At this time an A320 had begun his takeoff roll on [Runway] 24L. The Dauphin traveled westbound along Taxiway E then appeared to follow Taxiway BB to cross [Runway] 24L airborne and continue to the shoreline. As the ASDE alerted; I advised the Dauphin that his instructions were direct to the shore and advised him of traffic. He continued to the shoreline and I cleared him out and gave frequency change. I had the opportunity to review replays and recording of the incident. Even though the phraseology I used has worked in the past; seeing it from the pilot's perspective it seemed as though a bit ambiguous. I have reviewed ways in which I can 'tighten' up the phraseology and use more descriptive instructions to ensure the helicopters will remain in between the complexes. I feel that issuing traffic that would be off [Runway] 24L; even if not a factor; would be a good practice just to keep the pilot in the 'know' of what is going on. This is also a good reminder to be vigilant in read backs because as I reviewed the tape; the pilot read back cleared out direct north while I thought he said direct shore and did not realize because he flew westbound towards the shore on departure. I also feel that a standard Coast Guard departure could be put in place that would entail the aircraft taking off; remaining between the complexes; then cleared out north/south at the shoreline unless otherwise specifically noted to reduce phraseology and have everybody on the same page.
An A320 was holding in position on Runway 24L awaiting a takeoff clearance. The Helicopter Control position coordinated with my Local Assist that they would be departing a Coast Guard helicopter from the Coast Guard ramp at Taxiway E and E13. The helicopter would proceed westbound south of Runway 24L then northbound along the coastline at or below 150 FT. I informed the A320 of the departing helicopter off the left side of the runway and what the helicopter's instructions were; then issued a take off clearance. The A320 acknowledged the traffic call and began the takeoff roll. At about mid field; as the A320 started to rotate; the helicopter was airborne south of Runway 24L at about 100 FT. The helicopter then proceeded to fly directly northbound; crossing Runway 24L at the departure end and in front of the A320 as they were lifting off. The ASDE-X alarmed and stated 'Warning; Runway 24L Occupied.' By the time our attention was drawn to the situation; the helicopter had flown through the departure corridor and to the north. The A320 then asked whether the helicopter was supposed to remain south as I had instructed him earlier. I informed him that the instructions had not been followed by the helicopter. The A320 then said that the helicopter had passed directly in front of them on departure. I switched the A320 to Departure and informed the Supervisor of what had occurred. Although it has been a standard operation for many years at this airport; I believe the simultaneous departure of helicopters from Taxiway E and aircraft from Runway 24L can lead to an unsafe situation. These two points are very close together and can cause a conflict if one aircraft deviates in either direction for any reason. A procedure that keeps helicopters further away from active runways when taking off and landing should be established in order to ensure safety and resolve conflicts. A new departure routing along Taxiway R southbound; which is directly east of the Coast Guard ramp; would allow the helicopter to takeoff; climb in between the complexes; and proceed directly east or west as needed to avoid the runways. This would build in a larger safety margin and allow controllers to take quicker action if a pilot misinterprets or does not correctly follow a control instruction as was seen in this scenario.
LAX Tower Controller described an ASDE identified conflict when a Coast Guard helicopter departing on a 'rescue' mission failed to follow normal instructions; turn at the beach' and turn north early.