SMITH RICHARD D JR REVOLUTION MINI 500 near Middleboro, MA — 2010-04-07

Probable cause

A loss of engine coolant, which resulted in a loss of engine power during the pilot’s attempt to cushion a precautionary landing. Contributing to the accident was a disconnected engine coolant hose and the pilot's inadequate preflight inspection.

NTSB narrative

During a 50-minute flight the helicopter pilot observed the engine coolant temperature and the exhaust gas temperature increase. The pilot attempted a precautionary landing to a field; however, as he was adding power to cushion the landing, the engine lost power due to overheating. The helicopter then landed hard and rolled over. Postflight examination of the helicopter revealed that a coolant hose was disconnected and corrosion was noted on the radiator fins, indicating that leakage had occurred over a period of time. No coolant or coolant residue was found during the engine examination.

Analysis

Primary failure mode

Engine power loss

First missed decision gate

Pilot could have landed earlier to avoid engine overheating.

NTSB coding

• Loss of engine power (total) · Landing-flare/touchdown
• Preflight Inspection

Evidence available

• 2 docket documents

Docket documents2

• Other Pertinent Forms and Reports-Record of Conversation LA216form
• Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1form