Accident Details
On June 15, 2009, at approximately 1652 mountain daylight time, a Beech B100 (King Air) aircraft, registration N4490M, operated by Air Methods Corporation, encountered clear-air turbulence while descending through 7,000 feet mean sea level. The flight was en route to Rapid City Regional Airport, South Dakota, after departing Gordon Municipal Airport, Nebraska, at 1619. Visual meteorological conditions prevailed, and the flight was conducted under 14 CFR Part 135 on an instrument flight plan. The aircraft was configured as an air ambulance carrying one patient and four crew members.
Patient Restraint System
Before boarding, the patient was lying on an ambulance gurney and secured to a flexible lift system using waist and leg straps. This lift system, consisting of a plasticized sheet and full-body foam pad, allowed easy transfer to the aircraft-mounted stretcher. Once transferred, the patient was additionally restrained using the stretcher's waist and leg straps. However, the full-body pad and plasticized sheet completely covered the stretcher's over-the-shoulder restraints, rendering them unusable. The stretcher also had a back support that could be raised into an inclined position.
Sequence of Events
During the cruise descent, the aircraft encountered clear-air turbulence. The patient's upper torso fell off the stretcher, while his lower body remained restrained and attached to the elevated stretcher. After the turbulence, the patient's unrestrained head, neck, and upper torso were lying in the center aisle. Cabin crew stabilized the patient's neck before repositioning him onto the stretcher. The aircraft made an uneventful landing at its intended destination. The patient sustained a fracture of the C3 cervical vertebra.
Post-Accident Actions
Following the incident, the aeromedical transport company discontinued use of the flexible patient lift system model involved. They required that future lift systems allow the use of the aircraft stretcher's available over-the-shoulder restraints.