Midland, MI, USA
N2284U
BRANTLY B 2B
The private pilot was conducting a local flight in the helicopter with a passenger. After departing from an open field, the pilot flew along the perimeter of the field, and the passenger recalled that about halfway around the perimeter of the field, the helicopter began descending, slowly at first and then more rapidly. According to the passenger, the rotor speed increased, but the helicopter continued to descend. Ground-based video footage revealed that before it began descending, the helicopter was moving forward slowly when it yawed about 270° to the right. As it neared the ground, the helicopter again yawed to the right, completing nearly a 360° turn either immediately before or just after it contacted the ground. The helicopter came to rest on its left side. The engine continued to run after the helicopter came to rest, and the passenger shut it off. Airframe and engine examinations did not reveal evidence of any anomalies consistent with a pre-impact failure or malfunction. Surface wind conditions recorded at nearby airports were light and variable. Federal Aviation Administration publications regarding a loss of tail rotor effectiveness (LTE) state that in the event of a sudden, unanticipated right yaw, a pilot should apply full left pedal, simultaneously move the cyclic control forward to increase airspeed, and if altitude permits, reduce engine power. Factors that contribute to LTE are a high-power setting, which induces considerable main rotor downwash and more turbulence relative to a low power setting, and a slow forward speed, which may create variations in airflow around the tail rotor. The video footage showing a right yaw followed by a descent suggests that the pilot encountered LTE, which resulted in the 270° right yaw before the pilot was able to regain control. The additional power required by the tail rotor during the recovery reduced the power available to the main rotor and resulted in a descent that could not be arrested with the engine power available. It appeared that the pilot did not attempt to increase airspeed during the recovery, which reduced his ability to avoid impacting the ground.
HISTORY OF FLIGHTOn October 1, 2017, at 1447 eastern daylight time, a Brantly B-2B helicopter, N2284U, was substantially damaged when it impacted terrain in an open field near Midland, Michigan. The private pilot sustained fatal injuries, and the passenger sustained minor injuries. The helicopter was registered to Attitude Toys, Inc., and was operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from the open field shortly before the accident. Earlier in the day, the pilot flew the helicopter with a passenger from the Jack Barstow Airport (IKW), about 10 miles east-northeast of the accident site, to the open field to attend a family gathering that was taking place at a home adjacent to the field. The passenger on this flight stated that some minor turbulence was encountered, but the flight was otherwise uneventful. Ground-based video footage depicted the helicopter as it arrived at the family gathering. As the helicopter initially approached from the east, it began a gradual descent after it cleared the tree line east of the field. As the pilot brought the helicopter to a hover near the southwest corner of the field, it yawed to the right about 45°. The helicopter then hovered momentarily before yawing to the left about 90° to a southwesterly heading. It entered a gradual descent and began to move to the left, touched down momentarily, bounced, moved aft, and touched down again. After several seconds, the pilot lifted off again and relocated the helicopter closer to the southwest corner of the field before shutting down the helicopter. The passenger on the accident flight stated that during the family gathering, he decided to take a flight around the field with the pilot. He recalled that the helicopter "shook" a little on takeoff. He noted that the tail of the helicopter started to "sway" as they flew over the house located along the east edge of the field, but the pilot steadied the helicopter. Near the northeast corner of the field, the helicopter began descending, slowly at first and then more rapidly. The rotor speed increased, but the helicopter impacted the ground and rolled onto its left side before coming to rest. He added that the engine did not quit and that he turned if off with the ignition/magneto key after the accident. Ground-based video footage of the accident flight showed the helicopter parked on a west heading at the southwest corner of the grass field. Immediately after lifting off, the helicopter turned to the left toward the southwest and translated aft in a 4-ft hover. The helicopter became stationary in the hover for a few seconds. It then turned to a southeast heading and began to climb toward the east-northeast. As it reached the east edge of the field, the helicopter turned north to fly parallel to the perimeter road and adjacent tree line. About mid-field, the helicopter yawed to the right momentarily while the ground track appeared to continue north paralleling the road. As the helicopter reached the northeast corner of the field, it was moving forward slowly when it yawed about 270° to the right to a westerly heading. The helicopter then began a gradual descent. As it neared the ground, the helicopter yawed to the right, completing nearly a 360° turn either immediately before or just after it contacted the ground. PERSONNEL INFORMATIONA review of the pilot's logbook revealed that he had logged a total of 99.6 hours of flight experience in helicopters, 9.8 hours in gyrocopters, and 360.0 hours in single-engine airplanes. Of that flight time, 16.8 hours were in a Brantley B-2B helicopter with 11.5 hours as pilot-in-command. Additionally, he had logged 3.7 hours and 2.9 hours flight time in the accident helicopter within the 90-day and 30-day periods preceding the accident, respectively. AIRCRAFT INFORMATIONThe Federal Aviation Administration (FAA) issued an airworthiness certificate for the helicopter in October 1965. It was purchased by the current owner in September 2015. Helicopter maintenance records revealed that the most recent annual inspection was completed on October 1, 2016, at an airframe total time of 2,058.7 hours. At the time of the accident, the helicopter had accumulated 15.7 hours since the annual inspection. A receipt for 15.0 gallons of 100LL aviation fuel was found in the helicopter. The receipt indicated that the pilot purchased the fuel at IKW at 1218 on the day of the accident. METEOROLOGICAL INFORMATIONThe surface wind at IKW was from 160° at 5 knots at 1432 and from 170° at 3 knots at 1453. The surface wind at the Mt. Pleasant Municipal Airport (MOP), Mount Pleasant, Michigan, located 11.5 miles west of the accident site, was from 160° at 5 knots at 1433 and from 100° at 5 knots at 1454. AIRPORT INFORMATIONThe Federal Aviation Administration (FAA) issued an airworthiness certificate for the helicopter in October 1965. It was purchased by the current owner in September 2015. Helicopter maintenance records revealed that the most recent annual inspection was completed on October 1, 2016, at an airframe total time of 2,058.7 hours. At the time of the accident, the helicopter had accumulated 15.7 hours since the annual inspection. A receipt for 15.0 gallons of 100LL aviation fuel was found in the helicopter. The receipt indicated that the pilot purchased the fuel at IKW at 1218 on the day of the accident. WRECKAGE AND IMPACT INFORMATIONThe field was about 900 ft (north to south) by 800 ft (east to west). The accident site was located at the north boundary of the field adjacent to a shallow ravine. The helicopter came to rest on its left side and was oriented on a northwesterly heading. Airframe and engine examinations did not reveal evidence of any anomalies consistent with a pre-impact failure or malfunction. A detailed summary of the examinations is included in the docket associated with the investigation. ADDITIONAL INFORMATIONFAA Advisory Circular 90-95, Unanticipated Right Yaw in Helicopters, states that loss of tail rotor effectiveness (LTE) is a critical, low-speed aerodynamic flight characteristic that can result in an uncommanded rapid yaw rate and, if not corrected, can result in a loss of control. In order to reduce the onset of LTE, a pilot should avoid out-of-ground effect (OGE) hover and high-power demand situations. In the event of a sudden, unanticipated right yaw, a pilot should apply full left pedal, simultaneously move the cyclic control forward to increase airspeed, and if altitude permits, reduce engine power. A reduction in collective pitch will aid in arresting the yaw rate, but it may cause an increase in the descent rate. The FAA Helicopter Flying Handbook (FAA-H-8083-21A) states that factors that contribute to LTE are a high-power setting, which induces considerable main rotor downwash and more turbulence relative to a low power setting, and a slow forward speed, which may create variations in airflow around the tail rotor. Early detection of LTE followed by immediate corrective action is key to a safe recovery. Pilots should always set themselves up when conducting any maneuver to have enough height and space available to recover in the event that LTE is encountered. MEDICAL AND PATHOLOGICAL INFORMATIONThe Midland County Medical Examiner's Office, Midland, Michigan, conducted an autopsy of the pilot and determined that the pilot's death was due to blunt force trauma sustained in the accident. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing that identified atorvastatin at levels too low to quantify in blood and urine specimens. Atorvastatin is prescription medication used to reduce high cholesterol and is not considered to be impairing.
The pilot's failure to maintain control of the helicopter, which resulted in a loss of tail rotor effectiveness, and his failure to promptly initiate the proper recovery technique, which resulted in a descent that could not be arrested before impacting the terrain.
Source: NTSB Aviation Accident Database
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