History of Flight
On August 22, 2008, at 1847 eastern daylight time, a Bell 206A helicopter, registration N67AR, was destroyed when it impacted terrain during a forced landing near Barnesville, Pennsylvania. The certificated commercial pilot and passenger were seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which departed from Hazleton Municipal Airport (HZL), Hazleton, Pennsylvania. The flight was conducted under 14 Code of Federal Regulations Part 91.
Witnesses reported that the helicopter was scheduled to overfly a driving range at a golf course and drop golf balls for a charity event. One witness, the fire chief of a nearby fire department, observed the helicopter from the tee area. The helicopter initially flew over the golf course once, then returned to perform the ball drop about 100 yards downrange. It flew along a tree line on the east side of the driving range, then performed a 180-degree turn to align with the driving range (oriented roughly 035 degrees). At that time, the main rotor was below the tops of the trees, and the helicopter was traveling slowly uphill toward the tee area. The right door was removed, and a passenger was in the right aft seat. The flight path was described as "slightly erratic," with slight roll and fore/aft pitch oscillations. The helicopter then began to "spin" to the right while climbing and continuing forward toward the parking lot and clubhouse. It moved away from the driving range toward the 8th hole of the golf course before impacting the ground facing 180 degrees from its original flight path.
The chief proceeded to the crash site, noting fuel leaking and the engine running briefly after the accident. The weather was clear and warm. The wind, as observed by an FAA inspector from the far end of the driving range, was blowing toward the tee area up an approximate 5-degree slope. The U.S. and state flags at the top of the hill shifted between an uphill breeze and a breeze from the right side of the driving range. Based on the helicopter's flight path, the inspector discerned that it initially approached with a headwind, which became a tailwind as it flew uphill, shifting to a right quartering tailwind.
Another witness, walking from the parking lot to an area north of the driving range, saw the helicopter "spinning like a top" to the right before losing sight.
Personnel Information
The pilot, age 79, held a commercial pilot certificate with a rating for rotorcraft-helicopter and a private pilot certificate with ratings for airplane single and multiengine land. His most recent FAA second-class medical certificate was issued on October 4, 2004, reporting 12,300 total flight hours. A single pilot logbook showed entries for flights in the accident helicopter between April 2, 2000 and September 8, 2000, with a flight review sign-off. Subsequent entries included flight reviews on September 5, 2003, August 18, 2004, and July 3, 2006. No further logbook entries were located. Despite requests, the pilot refused to provide information about his pilot history or the accident flight.
Aircraft Information
According to FAA records, the helicopter was manufactured in 1970. Maintenance log review revealed discrepancies: the last annual inspection was performed prior to 2006, an emergency locator transmitter (ELT) inspection was due in 2006, and an ELT battery replacement was due in 2007.
Meteorological Information
Weather reported at Schuylkill County Airport (ZER), Pottsville, Pennsylvania, about 15 nautical miles southwest of the accident, at 1845, included wind from 130 degrees at 5 knots, visibility 10 statute miles, temperature 24°C, dewpoint 10°C, and altimeter setting 30.37 inches of mercury.
Wreckage and Impact Examination
The wreckage was examined on August 24, 2008, by an FAA inspector and a Bell Helicopter representative. The fuselage was oriented about 310 degrees magnetic and exhibited downward crush damage. Ground scars and airframe damage were consistent with a relatively tail-low attitude and no forward airspeed at impact. All pieces were within about 100 feet of the fuselage. The tailboom showed evidence of at least two main rotor strikes aft of the horizontal stabilizer, and the vertical fin assembly had ground contact damage. The high-skid landing gear skid tubes were separated from their mountings.
Control system examination revealed that the pilot-side cyclic stick could be moved with corresponding movement at the cyclic servos and swashplate inner ring, though limited laterally. The collective pitch control was found in the up position. Both main rotor pitch change links were fractured consistent with overload. The control tube from the pilot tail rotor pedals was bent, and the tail rotor control tube in the tailboom was fractured from main rotor strikes. The main transmission rotated freely with no metallic debris on the chip detector. The main driveshaft was disconnected at both ends, with fractured couplings. The freewheeling unit operated correctly.
Three fractures were observed in the tail rotor drive system: the steel driveshaft fractured from overload and contact with an engine combustor drain fitting; the number 3 shaft within the fuselage showed torsional overload fracture; and the shaft in the tailboom exhibited s-bending and rotational contact signatures, fractured where struck by the main rotor. The main rotor hub and blades remained attached; blades exhibited chordwise fracture and bending damage consistent with low rotor rpm at impact. Tail rotor blades showed overload fracture and bending. No evidence of pre-impact mechanical failure or malfunction was found.
Additional Information
FAA Advisory Circular (AC) 90-95, "Unanticipated Right Yaw in Helicopters," describes loss of tail rotor effectiveness (LTE) as a low-speed aerodynamic characteristic that can cause an uncommanded rapid yaw rate. It states that LTE may occur in all single main rotor helicopters at airspeeds less than 30 knots and is not related to maintenance malfunction. Paragraph 6 notes that maneuvers requiring high power and low airspeed with a left crosswind or tailwind create conditions for unanticipated right yaw. Paragraph 8 indicates that at airspeeds below translational lift, the tail rotor must provide nearly all directional control. Paragraph 9 advises avoiding tailwinds and high power demand situations during low-speed maneuvering.