ERA22FA207

The pilots’ inappropriate flight control inputs while in vortex ring state, which resulted in main rotor blade contact with the tail boom and a subsequent in-flight breakup. Also causal was the flight instructor’s inadequate monitoring of the flight.

The flight instructor was providing recurrent training to the operator’s pilots. During the first training flight of the day, a pilot who received instruction from the flight instructor described that the instructor told him to perform a vortex ring state (VRS) recovery maneuver, which the pilot accomplished, but shortly afterwards, the instructor requested that the pilot perform the maneuver again. During the second entry into VRS, the helicopter developed a very high descent rate, and the pilot was surprised when the flight instructor pilot did not intervene as the helicopter got deeper into the state. The pilot, feeling uncomfortable at that point, exited the very high descent rate on his own rather than waiting for further guidance from the instructor. The remainder of the first flight was uneventful. The second training flight of the day was the accident flight. A review of the recovered parametric data for this flight showed that the helicopter had been performing training maneuvers, and that shortly before the accident the helicopter was operating within the VRS envelope with a vertical descent rate between -800 to -1,300 feet per minute (fpm). This was consistent with the instructor directing the accident pilot to enter VRS for training purposes. Shortly thereafter, multiple abrupt control inputs were recorded, which including a forward cyclic input, followed by a nearly full-aft cyclic input within 1 second, as well as a concurrent full-down collective input with an increasing left pedal input. Based on contact signatures found on the helicopter’s main rotor blades and tailboom after the accident, it is likely that these abrupt control inputs resulted in the main rotor blades contacting the tail boom and the subsequent in-flight breakup of the helicopter. The parametric data and physical evidence observed during a postaccident examination of the wreckage revealed no evidence of any mechanical malfunctions or failures of the helicopter that would have precluded recovery from VRS. Based on this information, the reasons why the pilot(s) might have applied these abrupt control inputs could not be determined. Given the contextual commentary from the pilot of the previous training flight, it is likely the flight instructor did not provide adequate information to the accident pilot on how he would receive training for VRS, to include how they would identify, enter, and exit VRS.

On April 26, 2022, at 1300 eastern daylight time, a Bell Helicopter Textron Canada, 429, N507TJ, was substantially damaged when it was involved in an accident near Elba, New York. The flight instructor and pilot receiving instruction were fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. A representative of the operator stated that the instructional flight was recurrent training being conducted by the helicopter manufacturer’s flight instructor with multiple training flights planned throughout the day; the accident flight was the second flight of the day. The first pilot who received training from the flight instructor on the morning of the accident flight stated that during their flight they entered vortex ring state (VRS) with a very high descent rate, which was confirmed by the flight data recovered from the accident helicopter. While in VRS, the pilot stated that he didn’t know why they were going so deep into VRS and that the instructor was just sitting there, “hands on his lap.” So, the pilot, feeling uncomfortable at that point, had to exit this very high descent rate on his own rather than waiting for further guidance from the instructor pilot. The helicopter was equipped with an Electronic Data Recorder (EDR) within its Display Unit (DU), also known as the Pilot Flight Display and Multi-Function Display, that recorded flight, navigation, engine, and usage parameters every half second. It was also equipped with a SKYTRAC transceiver that facilitated real-time fleet awareness, group communications, and systems performance trending and analysis. The accident flight was also recorded by automatic dependent surveillance-broadcast (ADS-B). ADS-B data, combined with the DU and SKYTRAC data sources, revealed that the accident pilot and the flight instructor departed Genesee County Airport (GVQ) Batavia, New York at 1111, and performed multiple maneuvers in the immediate vicinity of the airport before departing to the east. About 20 minutes later, the helicopter returned to the airport and performed additional maneuvers in the airport traffic pattern for about 30 minutes before again departing the traffic pattern. From about 1223 to 12:55, the pilot and instructor practiced single-engine training and dual-engine failure training with autorotations. These training maneuvers were completed about 4 minutes and 30 seconds before the accident occurred. About 12:56, the helicopter was flying over the airport and turned north. About 12:58, the helicopter was approximately 2 nm north-northeast of the airport and began a clockwise circular pattern. From 12:59:26 to 12:59:44 (18 seconds), the helicopter was operating in an envelope conducive to VRS. At 12:59:47 there were multiple abrupt control inputs; the cyclic was nearly full forward and to the left with right antitorque pedal input applied. The collective lever position was in the full down position; the airspeed was decreasing from 26 knots to 9 knots with the helicopter’s vertical descent rate increasing from -800 to -1,300 fpm. Several eyewitnesses observed and heard the helicopter flying overhead before the accident and throughout the accident sequence. One stated that he observed the helicopter “almost stationary” after it flew over, and then as it started to fly away, he heard a loud “bang”, and the helicopter began to descend out of control. An additional witness stated that the helicopter was hovering before it “fell apart” with the fuselage falling separately, and another witness stated she did not see the helicopter but heard what sounded like an engine making a “whooshing” sound, and then “three loud and rapid cracks” in succession. She further stated that she heard the helicopter impact the ground and heard the rotor blades striking the ground rapidly. AIRCRAFT INFORMATION The accident helicopter was maintained by the operator under the manufacturer’s recommended inspection program. The last entry in the helicopter’s airframe maintenance logbook was dated April 24, 2022, and reflected airframe and engine total times of 1,039.6 hours. Each engine contained an electronic engine control (EEC) and a data collection unit (DCU). Attempts were made to recover stored data within these units, but no data could be recovered from the No. 1 engine EEC and DCU due to impact damage. However, data were recovered from the No. 2 engine EEC and DCU. The recovered data showed that there were no faults or exceedances recorded during the flight. WRECKAGE AND IMPACT INFORMATION The helicopter fuselage, containing the cockpit, engine, transmission, and rotor head assembly, struck electrical distribution wires as it impacted the terrain at an elevation of about 1,220 ft msl and was oriented on a heading of about 190°. The helicopter came to rest on its left side; the fuselage impacted the ground and crushed inwards and fractured into two large sections, leaving no occupiable space in the cockpit. A small post-impact fire developed in the engine compartment but was quickly extinguished by first responders. The wreckage path was about 2,500 ft-long and oriented in a direction of 250° magnetic from the first wreckage pieces towards the main fuselage resting place. The tail boom had fractured and separated into two sections with angled fracture lines consistent with main rotor blade contact. The forward tail boom section remained attached to the upper section of the fuselage about 8 ft aft of the engine exhaust. The aft tail boom, containing the tail rotor, partial drive shaft, vertical fin, and horizontal stabilizer remained largely intact and was discovered about 390 ft on a heading of about 075° from the main wreckage. A 16-inch section of the tail rotor drive shaft cover and a partial carbon fiber tail rotor shaft was discovered 1,620 ft and a 072° heading from the main wreckage; it exhibited an angled slice line consistent with main rotor blade contact. The tail rotor remained installed on the tail rotor gearbox, which itself remained installed on the separated empennage. The four tail rotor blades did not exhibit significant damage. The tail rotor input control was manually actuated and a corresponding change of pitch for all four tail rotor blades was observed. The tail rotor pitch control tube had fractured forward of the tail rotor gearbox and exhibited multiple fractures through its normal routing through the tail boom. The tail rotor servo actuator and stability and control augmentation system (SCAS) actuator remained installed and connected to the tail rotor pitch control tube. The forward tail rotor drive shaft remained connected to the main gearbox but had fractured about midway to the fan blower shaft. The fan blower remained installed on the airframe. The forward segmented drive shaft remained attached to the fan blower shaft and was continuous through the forward snubber but had fractured near its connection to the aft segmented drive shaft and the hanger bearing; the hanger bearing was not present. The aft segmented drive shaft had fractured near its forward end and at the tail gearbox input flange. A portion of the aft snubber remained attached to its snubber mount. The tail rotor gearbox remained installed on the empennage. The tail rotor was manually rotated through several 360° rotation of the tail rotor gearbox input flange and resulted in a corresponding rotation of the tail rotor. The rotation was smooth and there were no abnormal sounds or evidence of binding or other restrictions. Examination of the flight control system consisting of the cyclic and collective push-pull tubes were traced through cuts made to facilitate recovery and overload separation damage to each of their respective servo actuators, cockpit controls, and their respective hydraulic system. The collective push-pull tube was continuous through the forward bellcrank up to the collective servo actuat