On March 1, 1990, a Bell BH-47G3B2 (registration N4073G) operated by Richard H. Butz was involved in an aviation accident near Des Moines, WA. Investigators recorded the probable cause as: Engine roughness and RPM decrease during cruise flight leading to loss of power and subsequent ditching. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A light aircraft experienced engine roughness and power loss during cruise flight, forcing the pilot to ditch in a saltwater bay where he was rescued by a private boat.
What happened
The incident occurred during cruise flight when the aircraft's engine began running roughly. During this event, the revolutions per minute (RPM) decreased from 3200 to 2800. The pilot attempted to reach shore but was unable to do so with the available power remaining in the system.
Consequently, the pilot decided to ditch the aircraft in a saltwater bay. Following the water landing, the pilot was recovered from the water by a private boat. The aircraft sank in 300 feet of deep water and was not recovered.
Probable cause
Engine roughness and RPM decrease during cruise flight leading to loss of power and subsequent ditching.