On March 1, 1994, a Bell 47G-5 (registration N7043J) was involved in an aviation accident near Plymouth, MA. Investigators recorded the probable cause as: The pilot's failure to maintain adequate clearance of the fuel truck from the aircraft, which resulted in the main rotor striking the fuel hose and truck during refueling operation. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During refueling of a Bell 47 after a training flight, turning rotor blades struck a fuel hose and truck, causing the hose to hit the CFI. Investigation found the truck was parked about 3.5 feet from the blades, violating company policy requiring a 10-foot clearance.
Incident Details
A student pilot receiving instruction in a Bell 47 helicopter from a certified flight instructor (CFI) completed a 1.5-hour dual instruction flight. After landing at the departure airport to refuel, the helicopter was left idling with the RSP at the controls while the CFI exited to retrieve the fuel truck. The CFI returned with the truck, refueled the helicopter, and was returning the fuel hose to the truck when the turning rotor blades struck the hose and the fuel truck. The hose in turn struck the CFI.
Investigation Findings
The investigation revealed that the fuel truck had been parked approximately 3.5 feet from the turning rotor blades. Company policy mandated a minimum clearance of 10 feet between the truck and the rotor blades. Additionally, a re-enactment of the hose stowage procedure to the side of the fuel truck showed a tendency for the hose to deflect upward into the rotor tip path plane.