NTSB Identification: FTW01LA166
14 CFR Part 91: General Aviation
Accident occurred Friday, July 20, 2001 in Decatur, TX
Probable Cause Approval Date: 02/20/2002
Aircraft: Eurocopter BK117-C1, registration: N313LS
Injuries: 2 Serious,1 Minor.
NTSB investigators may have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The twin-engine helicopter departed on a positioning flight to pick up a medical patient. While in cruise flight, at 2,000 feet, both engines experienced a total loss of power. The pilot attempted to autorotate to a field; however, the helicopter impacted trees and came to rest on its right side. The pilot reported that he did not notice any warning lights immediately prior to or during the loss of engine power events. However, it was noted during a post-accident examination of the helicopter that the pilot instrument light and console light variable resistor control was in the ON position. This control dims the master caution and annunciator panel lights for night operations. The NTSB IIC noted that the master caution and annunciator lights were not visible in daylight with the pilot and console variable resistor control in the ON position. Although the two fuel transfer pump switches were found in the ON (normal operating) position, examination of the fuel system provided evidence that the dual engine power loss was the result of fuel starvation due to these switches not being ON during the majority of the flight. The fuel supply lines to the engines were found empty, a nominal amount of fuel was found in the fuel filters, and the fuel quantity indicator displayed 4, 0, and 15 gallons of fuel in the #1 supply, #2 supply, and forward main fuel tanks, respectively. The function of the fuel transfer pumps is to transfer fuel from the forward main tank to the two supply tanks. The fuel transfer pumps were operated during the post-accident examination by turning on their respective switches and it was noted that fuel began to flow into the supply tanks. Additionally, it was noted that the fuel transfer pump caution lights (which are illuminated when the pumps are off) extinguished when the pumps were turned on. The engines were placed in a test cell and both operated with no anomalies noted. The normal operating checklist calls, in part, for the pilot to set the instrument lights as required, test the annunciator panel for operation, and turn on the transfer pumps after engine start.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: the pilot's failure to follow the checklist and turn on the fuel transfer pumps, which resulted in fuel starvation and a dual loss of engine power while in cruise flight. Full narrative available
Index for Jul2001 | Index of months