NTSB Identification: DEN08MA116A
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Sunday, June 29, 2008 in Flagstaff, AZ
Probable Cause Approval Date: 05/07/2009
Aircraft: BELL 407, registration: N407GA
Injuries: 7 Fatal.
NTSB investigators traveled in support of this investigation and used data obtained from various sources to prepare this aircraft accident report.
Both Emergency Medical Services (EMS) helicopters were on approach to the Flagstaff Medical Center (FMC) helipad to drop off patients. During the flights, the N407MJ pilot had established two-way communications with his communications center and provided position reports, and the N407GA pilot had established two-way communications with FMC's communications center (which was his company's communication center and which also monitored and advised all traffic at the helipad) and provided position reports. The FMC communications center transportation coordinator advised the N407GA pilot that N407MJ would also be dropping off a patient at FMC. The coordinator also advised N407MJ's communication center that N407GA would be landing at FMC, but the N407MJ's communication center did not inform the N407MJ pilot nor was it required to do so.
Established arrival and departure procedures for the FMC helipad required pilots to contact the FMC communications center at the earliest opportunity or at a minimum of 5 miles from the helipad. According to the FMC communications center's staff, N407MJ's pilot did not make the required contact with the communications center at any time during the flight.
About 3 minutes before the collision, N407GA dropped off a medical crewmember at the local airport (about 5 miles south of the medical center) to reduce the weight on the aircraft and to improve aircraft performance during landing at the medical center. According to witness information, flight-track data, and a hospital surveillance video, N407GA approached the helipad from the south, flying past or slightly inside the southeast tip of the noise abatement area on a direct line toward a final approach position just east of the helipad. However, according to helipad arrival guidelines and company procedures, N407GA should have approached the helipad from farther to the east. (After the on-scene accident site investigation, the Air Methods regional chief pilot, accompanied by NTSB investigators, flew the accident route in another Air Methods Bell 407 using GPS data retrieved from N407GA. According to the regional chief pilot, the “trained route” was much farther to the east and not in a direct line to the hospital.) N407MJ approached the helipad from the northeast, and it is likely that the pilot would have been visually scanning the typical flight paths, as described in the noise abatement and helipad arrival guidelines, that other aircraft approaching the medical center would have used. Thus, if N407GA had approached from a more typical direction, the pilot of N407MJ may have been more likely to see and avoid it.
At the time of the collision, both pilots were at a point in the approach where their visual attention typically would have been more focused on the helipad in preparation for landing, rather than on scanning the surrounding area for other traffic. The helicopters collided approximately 1/4 mile east of the helipad. There were no communications from either helicopter just prior to or after the collision.
Neither helicopter was equipped with a traffic collision avoidance system, nor was such a system required. Had such a system been on board, it likely would have alerted the pilots to the traffic conflict so they could take evasive action before collision. No radar or air traffic control services were available for the helipad operations to ensure separation. However, if N407MJ's pilot had contacted the FMC communications center, as required, the FMC transportation coordinator likely would have told him directly that another aircraft was expected at the helipad. If the pilot had known to expect another aircraft in the area, he would have been more likely to look for the other aircraft.
Nevertheless, the pilots were responsible for maintaining vigilance and to see and avoid other aircraft at all times. Under 14 Code of Federal Regulations Sections 91.111 and 91.113, all pilots are responsible for keeping a safe distance from other aircraft and for maintaining vigilance so as to see and avoid other aircraft. Advisory Circular 90-48C, "Pilots' Role in Collision Avoidance," amplifies the see-and-avoid concept by stating that all pilots should remain constantly alert to all traffic movement within their field of vision and that they should scan the entire visual field outside of their aircraft to ensure that conflicting traffic would be detected.
Examination of the wreckages revealed that N407MJ's tail rotor contacted the forward fuselage of N407GA, and N407GA's main rotor blades contacted and separated N407MJ's tail boom. The recovered wreckages showed no evidence of any preimpact structural, engine, or system failures.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: Both helicopter pilots’ failure to see and avoid the other helicopter on approach to the helipad. Contributing to the accident were the failure of N407GA’s pilot to follow flight arrival route guidelines, and the failure of N407MJ’s pilot to follow communications guidelines requiring him to report his position within a minimum of 5 miles from the helipad. Full narrative available
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