Scottish Aviation SERIES 100 MDL 101 near Lake Pleasant, AZ — 2018-11-17

Probable cause

Impact with a lake for undetermined reasons.

NTSB narrative

The pilot reported that during a pleasure flight over a lake, about 700 ft above ground level, the engine started to shake and subsequently lost all power. The pilot attempted to restart the engine by turning the auxiliary fuel pump on, and he dove the airplane toward the water so that the windmilling propeller would help to restart the engine. The engine started, but the pilot estimated that it was only producing about 50% power. The pilot thought that he might be able to maintain or gain some altitude to reach a nearby runway; however, during the climb, the engine lost all power again. The pilot then initiated a forced landing to the lake. Witnesses around the lake reported seeing the airplane flying at low altitude. One witness stated that the engine sounded normal but that the airplane was flying erratically. Another witness saw the airplane about 40 ft above the water. He did not hear any unusual noises emanating from the engine. The airplane and engine remained submerged in the lake for about 3 weeks before recovery. The right wing was not recovered. Cursory examination of the engine revealed continuity to the accessory drive when the propeller was rotated by hand; however, the examination was insufficient to determine whether or for what reason a loss of engine power may have occurred.

Analysis

Primary failure mode

Engine power loss

First missed decision gate

Pilot could have aborted the flight after initial engine issues.

NTSB coding

• Inflight upset · Maneuvering-low-alt flying

Evidence available

• 4 docket documents

Docket documents4

• PILOT'S STATEMENTinterview
• WITNESS STATEMENTSinterview
• FUEL RECEIPTother
• FAA INSPECTION REPORTreport

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