19980724023869A

Accident · Substantial damage

FAA accident report · Bell UH1H · Libby, MT · July 24, 1998

Date
July 24, 1998 · 08:30 local
Place
Libby, MT
Phase of flight
Hovering
Operating rules
Rotorcraft external load (Part 133)
Operator
WYFL
Damage
Substantial damage
Aircraft
N83NW
NTSB investigation
NTSBSEA98LA146
Reported as
Bell UH1H
Reported engine
Lycoming T53L13B
Fatal injuries
0
Pilot’s flight hours
8,660 total4,160 in this make and model107 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

Long line failed rapped around tail rotor. Autorotated to a road. (.4)the pilot stated that while conducting external load logging operations, he was hooked up to a tree length root wad which had been knocked over and topped. He picked up the tree length and laid it over 180 degrees from its original position in order to break the roots from the ground. With the roots loose, he started a takeoff and the tree left the ground and was in the air for approximately 25-50 yards. The roots then impacted the ground; the kevlar long-line snapped about midpoint and the broken end rebounded up into the tail rotor. The pilot stated that he immediately realized he had a tail rotor failure. He informed the ground crew and found the only open area, which was approximately 100 yards from the point of failure. On the second 360 degree spin, he reduced power when the nose was pointed at the intended crash site. He stated that he realized he was too low to make it, so he pulled pitch, which put him in a rapid spin. He struck some trees on his second or third spin and then fell. After impact, he evacuated from the helicopter. (-23)during logging operation 45 miles north of Libby, MT., aircraft experienced tail rotor failure after external load cable failed and recoiled into tail rotot. Aircraft was landed on road near worksite.

As the FAA filed it

LONG LINE FAILED RAPPED AROUND TAIL ROTOR. AUTOROTATED TO A ROAD. (.4)THE PILOT STATED THAT WHILE CONDUCTING EXTERNAL LOAD LOGGING OPERATIONS, HE WAS HOOKED UP TO A TREE LENGTH ROOT WAD WHICH HAD BEEN KNOCKED OVER AND TOPPED. HE PICKED UP THE TREE LENGTH AND LAID IT OVER 180 DEGREES FROM ITS ORIGINAL POSITION IN ORDER TO BREAK THE ROOTS FROM THE GROUND. WITH THE ROOTS LOOSE, HE STARTED A TAKEOFF AND THE TREE LEFT THE GROUND AND WAS IN THE AIR FOR APPROXIMATELY 25-50 YARDS. THE ROOTS THEN IMPACTED THE GROUND; THE KEVLAR LONG-LINE SNAPPED ABOUT MIDPOINT AND THE BROKEN END REBOUNDED UP INTO THE TAIL ROTOR. THE PILOT STATED THAT HE IMMEDIATELY REALIZED HE HAD A TAIL ROTOR FAILURE. HE INFORMED THE GROUND CREW AND FOUND THE ONLY OPEN AREA, WHICH WAS APPROXIMATELY 100 YARDS FROM THE POINT OF FAILURE. ON THE SECOND 360 DEGREE SPIN, HE REDUCED POWER WHEN THE NOSE WAS POINTED AT THE INTENDED CRASH SITE. HE STATED THAT HE REALIZED HE WAS TOO LOW TO MAKE IT, SO HE PULLED PITCH, WHICH PUT HIM IN A RAPID SPIN. HE STRUCK SOME TREES ON HIS SECOND OR THIRD SPIN AND THEN FELL. AFTER IMPACT, HE EVACUATED FROM THE HELICOPTER. (-23)DURING LOGGING OPERATION 45 MILES NORTH OF LIBBY, MT., AIRCRAFT EXPERIENCED TAIL ROTOR FAILURE AFTER EXTERNAL LOAD CABLE FAILED AND RECOILED INTO TAIL ROTOT. AIRCRAFT WAS LANDED ON ROAD NEAR WORKSITE.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.