On October 17, 1999, a Robinson R-22 (registration N83574) was involved in an aviation accident near Sunny Isles, FL. Investigators recorded the probable cause as: A loss of engine power while maneuvering due to improper ignition timing by unknown person(s) resulting in an emergency descent and collision with the water. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 related events involving the same aircraft type or operator are linked below.
A helicopter experienced rising cylinder head and oil temperatures, leading the pilot to ditch in shallow water. Post-crash analysis found abnormal magneto timing and clutch overtorque events.
Incident Description
After about one hour of flight at approximately 200 feet offshore, the helicopter descended from about 500 feet above ground level to about 200 feet and headed directly toward the beach. Once overhead the beach, the pilot stated that the cylinder head and oil temperature indications began rising rapidly. He looked for a place to conduct an autorotation. Finding no suitable area due to the density of bathers and losing power, the pilot elected to ditch offshore in about 8 feet of water.
Post-Crash Analysis
A post-crash test run of the engine revealed normal operation except that the magneto timing had been adjusted as far advanced as possible. Factory post-crash analysis of the main rotor clutch and shaft revealed that the clutch had sustained two severe overtorque events, most likely as a result of two or more main rotor blade strikes during the accident.