NTSB Factual Report

On September 19, 2006, about 1640 eastern daylight time, a ground crewmember was seriously injured when a sling load was inadvertently dropped from a Garlick OH58A, N802JB, in East Bridgewater, Massachusetts. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed. The flight was not operating on a flight plan while conducting multiple local flights from a cranberry bog. The external sling load flight was conducted under 14 Code of Federal Regulations Part 133.

According to the pilot, he was airlifting empty cranberry bins to the bog to be filled. The bins were lifted from a 48-foot flatbed trailer, about 4 feet away from the ground crewmember, a 9-year hook-up veteran.

After the fifth lift, the ground crewmember decided to "run over and help the truck driver of the previously loaded trailer." Although all ground personnel had hard hats with a combination ear muffs/radio receiver and microphone, the ground crewmember did not advise the pilot of his intentions, and ran under the track flown during the previous four loads. As the helicopter flew over him, the cargo hook opened, uncommanded by the pilot, and the bins fell about 8 feet on to the ground crewmember.

The pilot noted that the cargo hook system included a primary hook attached to the belly of the helicopter, a lanyard attached to the primary hook, and a secondary, emergency release hook at the bottom of the lanyard, that attached to a load sling. After the accident, the pilot noticed that the lanyard with the secondary, emergency release hook was not attached to the primary hook. He reattached it to the primary hook and tugged on it, and the load beam opened. The primary hook assembly was subsequently removed from the helicopter and provided to Federal Aviation Administration (FAA) inspectors for further examination.

When a new primary cargo hook assembly was installed, and when the emergency release cable was attached, tension was found to be on the primary hook release mechanism, to the extent that "the slightest movement of the cable caused the hook load beam to open."

According to an FAA inspector, the emergency release cable exited a fitting on the belly of the helicopter and entered another fitting approximately 4 1/2 inches away. The fittings were not aligned, and were offset about 1 1/2 inches. Ground testing revealed that cable tension would sometimes release the primary hook without command.

According to the operator, the hook assembly had previously been removed from another helicopter in 2002, and that helicopter had received the assembly in 1997 at a completion center in Tennessee. The installed release cable was Bell part number 206-072-903-101; however, the correct part number was 206-072-903-1, which was approximately 1 inch longer, and would have allowed enough slack to normally preclude tension on the cargo hook manual release mechanism. After discovering the different part numbers, the operator found that another of his helicopters also had the shorter release cable, and he changed it to the longer one as well.

According to a representative from Bell Helicopter, the shorter cable was intended for use on the Bell 206L LongRanger, while the longer cable was meant for the Bell 206 JetRanger.

NTSB Probable Cause

The completion center's installation of the incorrect (shorter) release cable, and the ground crewmember's improper movement under the flight path during a bin transfer.