Introduction
An emergency medical services (EMS) helicopter crashed while transporting an 11-day-old infant patient from a hospital in Battle Mountain, Nevada, to a hospital in Reno. The night flight ended when the helicopter struck terrain at an elevation of about 8,600 feet along its direct course line.
Flight Details
The pilot had a choice between a direct route crossing rugged mountainous terrain with maximum ground elevations of about 9,000 feet, or a longer route following an interstate highway with maximum elevations of about 6,000 feet. After takeoff, the pilot reported departure to the Elko county dispatch center and stated an estimated time en route of 1 hour 20 minutes. No further radio communications were received.
Accident Sequence
Radar data covering about 4 minutes of flight before signal loss due to terrain were consistent with the helicopter following the direct route. A search began about 4 hours after the helicopter failed to arrive at the destination, and the wreckage was located the following morning. Physical evidence indicated the helicopter was in level flight at impact and consistent with controlled flight into terrain.
Investigation Findings
No evidence of preimpact mechanical discrepancies with the airframe or systems was found. Rotational damage to rotor blades and transmission components was consistent with normal engine operation at impact. The two closest aviation weather reporting stations (31 and 54 nautical miles from the accident site) reported 10 miles visibility, clear skies below 12,000 feet, and no precipitation at the time of the accident. However, satellite images taken about 1 hour before the accident indicated cloud cover over the site, and weather radar images about 1.5 hours before indicated light precipitation in the vicinity. The exact weather conditions at the time and location could not be determined.
Weather Briefing and Pilot Decisions
No record was found that the pilot obtained a weather briefing before departure. If he had, he would likely have learned of the cloud cover and light precipitation along his planned route. Studies conducted by the National Transportation Safety Board and industry indicate that the urgent nature of EMS missions can result in inaccurate or incomplete preflight planning and poor pilot judgment. The fact that the patient was an infant may have placed additional pressure on the pilot to take the direct route.
Equipment and Search Delay
The helicopter was not equipped with an enhanced ground proximity warning system (EGPWS), and none was required. If installed, an EGPWS would have alerted the pilot of high terrain at least 35 seconds before impact. Although the search was not initiated until about 4 hours after the accident, despite company flight-following procedures requiring a report after a missed 15-minute position report, the accident was not survivable and a faster notification would not have changed the outcome.