Sequence of Events
A sightseeing tour helicopter carrying four passengers encountered instrument meteorological conditions along its route of flight. The pilot landed at 7,500 feet mean sea level to wait for the weather to clear. During the landing, passengers heard and observed the low rotor RPM annunciator. After the weather cleared, a low battery prevented the engine from starting.
A second helicopter, the accident aircraft, with a pilot and a mechanic was dispatched to retrieve the passengers. During lift-off, the passengers again heard and observed the low rotor RPM annunciator. The helicopter's nose pivoted about 45 degrees to the right as the aircraft departed downslope. The helicopter's left landing gear skid struck a small ridge, and the aircraft rolled over.
Aftermath
Both the sightseeing tour helicopter and the accident helicopter, along with all occupants, remained overnight until rescue the following day.