Amateur-built EXEC N162CT accident near Chino Hills, California

Probable cause

A total loss of engine power due to fuel exhaustion as a result of both the owner's and the pilot's failure to determine or monitor the remaining fuel quantity during the flight. Contributing to the accident was the manufacturer's lack of fuel consumption rate data for planning purposes.

NTSB analysis

The flight instructor/owner of the experimental amateur-built helicopter took the rotorcraft-rated private pilot on an informal demonstration flight. The two spent about 40 minutes conducting traffic pattern work at a local airport and then departed the area, flying about 500 feet above ground level. The private pilot was the pilot flying. When the helicopter was about 7 miles from the airport, the pilot noticed that the engine "sputtered," and called it to the attention of the owner, who then took control of the helicopter. The engine ceased operating about the same time. The owner initiated a 180-degree autorotation to a vacant field. Due to some forward speed at touchdown, the landing skids dug into the turf and the helicopter pitched nose down. The main rotor struck the ground and also severed the tail boom, and the helicopter rolled onto its left side. Postaccident examination indicated that there was less than 1 gallon of fuel remaining on board.

The manufacturer's pilots operating handbook did not contain any fuel consumption rate information; the only reference to range or endurance was the statement "Range with maximum fuel at optimum power 180 miles/2 hrs." The owner reported that he began the flight with 17 gallons (the maximum quantity) , and that the engine consumed about 9 gallons per hour; he did not specify the source of that information or the power setting or flight mode for that consumption rate. Since the fuel consumption rate for takeoffs and traffic pattern work can be significantly higher than that for cruise flight at "optimum power," the endurance of the helicopter during the accident flight would have been commensurately less than 2 hours. The helicopter was equipped with a fuel quantity gauge and cockpit instrumentation also provided a means for a pilot to determine the approximate remaining fuel quantity in flight by selecting the "fuel used"' option on the cockpit display. Neither the pilot nor the owner reported using either means to check or monitor fuel quantity during the flight.

Text from the NTSB. Open the NTSB docket for WPR11LA373 for the full record.