It was the middle of a short December day when a call came to a helicopter emergency medical service (HEMS) firm in Soldotna, Alaska, requesting transport for a patient to Anchorage from a clinic in Cordova. Soldotna is south and west of Anchorage; Cordova is 127 nm east. The helicopter would first have to position to Cordova before loading the patient. By the time the flight would be ready to leave there, the sun, which would have set before 4 o’clock, would be gone, and the long northern twilight almost ended. The moon, a waning crescent, would be down, and the unpeopled wilderness between the few towns along the route would be utterly dark.
Normally, the hospital in Cordova would have requested an airplane, which could go IFR, for the transfer; but all medical transport airplanes were already booked. This HEMS operator flew VFR only. Part 135, under which the flight would operate, requires that helicopters operating in Class G airspace under VFR have visual contact with the surface or, at night, with lights on the surface. Night vision goggles were used to comply with this requirement.
