AGUSTAWESTLAND PHILADELPHIA CO AW119MKII

Full Narrative

On September 19, 2024, about 2003 eastern daylight time, an Agustawestland Philadelphia Co. AW119MKII helicopter, N281MC, was substantially damaged when it was involved in an accident near Canadaigua, New York. The commercial pilot was not injured and two medical crewmembers sustained minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 135 air medical flight.
According to the pilot he had transported a patient to a local hospital and was returning to Canadaigua Airport (IUA) at night using night vision goggles (NVGs). The flight was uneventful until reaching the airport. On approach to the base ramp, obstacles were called out and the pilot continued the approach to a grass landing zone adjacent to the ramp. When the helicopter was about 100 ft above ground level (agl), the landing light illuminated. When the helicopter was about 10 ft agl, it lunged rapidly forward and downward and “rolled very slightly left.” The left skid impacted the ground, followed by the right skid, and the helicopter rapidly rotated to the left. There was a tail-down rocking movement, the pilot rolled the throttle back to idle, and the helicopter came to a stop. The engine continued to operate and the pilot was able to shut the engine down with the assistance of the medical crewmember in the left cockpit seat. The pilot and two medical crewmembers exited the helicopter and were met by first responders.
The medical crewmember in the left cockpit seat reported that the flight was approaching the landing zone (LZ) at about 100 ft agl. He felt that it was not normal to be going that fast approaching the base. He noticed that the pilot appeared to be adjusting his NVGs with his right hand and “grabbing the collective” with his left hand. The medical crewmember looked outside the cockpit to regain visual with the ground and “realized we were rapidly approaching it.” Before he could call out to abort the landing, “we were coming in too fast” and the helicopter struck the ground tail first. The helicopter then “rapidly hit the ground with the nose of the aircraft” and the helicopter began shaking violently. The pilot had difficulty securing the helicopter and the medical crewmember provided assistance.
The helicopter came to rest upright in the grass, about 210 ft west of the planned LZ. The operator described the LZ as a mowed grass landing pad, with orange cones to define it. Initial examination of the helicopter revealed substantial damage to the fuselage, main rotor, tail boom, and tail rotor.
The helicopter was equipped with a Genesys Aerosystems avionics suite. Flight and systems data were recorded for the entire accident flight through redundant channels until the removal of battery power during the accident sequence.
Analysis of the data revealed that the preflight, engine start, takeoff, and cruise portions of the flight were uneventful and no CAS messages were displayed to the pilot on the integrated display units other than normal messages during engine start and main rotor spin-up. During the cruise portion of flight, the helicopter was between 1,700 ft mean sea level (msl) and 1,950 ft msl, and the indicated airspeed (IAS) varied between 130 and 138 kts. At 1959:40, the pilot began to progressively reduce torque (TQ) demand, resulting in a descent down to about 1,300 ft and 110 kts. The helicopter was about 1.87 nautical miles from the LZ at the time.
At 2003:28, the pilot maintained a steady and controlled descent toward the LZ, with vertical speed between -50 and -260 ft/minute and slowly decelerating to 35 kts IAS. The landing light illuminated at 2003:33. The data then showed that the pilot commanded a steady increase in pitch from 5° to 12° at 2003:43. Concurrently, TQ demand reduced from 40% to 35% at 2003:36. The rate of descent then increased rapidly from 140 ft/minute to more than 500 ft/minute. At this point, the helicopter was about 10 ft agl. No CAS messages or other abnormal systems conditions were recorded to this point.
At 2003:45, a sudden aircraft pitch change occurred, from 12° up to 25° down in about 1 second, consistent with ground impact. Vertical speed was in excess of 600 ft/minute descent. During the 4 seconds prior to this point the pilot slowly increased engine TQ from 37% to 63%. During the next 3 seconds, the aircraft had three full pitch excursions while yawing 220° to the right. After the helicopter came to rest, the engine continued to operate at 72% engine fan speed (N1) at 500°C inter-turbine temperature (ITT) until recorded data stopped at 2004:18.
Postaccident examination showed that the helicopter’s fuselage was generally intact. There was some deformation of the lower left fuselage structure near the left landing gear skid attachment. The tail boom remained attached to the fuselage. The horizontal stabilizer remained attached to the tail boom; however, there was structural damage to the left outboard end of the stabilizer. The upper fin remained in place and was damaged; however, the lower fin and tail skid separated during ground impact. The skid-type landing gear partially separated during ground impact. All separated sections of the landing gear showed signatures of overload failure.
The tail gear box (TGB) casing was broken in half, consistent with ground impact; the outermost part of the casing detached from the aircraft, together with the entire tail rotor assembly. The tail rotor blades remained attached; however, the outboard portions of the composite blades exhibited rotational damage. The tail rotor pitch links were firmly installed. The tail rotor “spider” assembly was undamaged and the cover plug was still in position, indicating that the duplex bearing was still retained by its nut in the proper position. The TGB detector plug was dislodged from its housing, and no oil remained in the TGB. The magnetic plug was free of metallic debris. The tail rotor drive shaft was sheared by static overload. Continuity of the tail rotor pedal control chain was verified with the connecting rod on the TGB.
The forward (blue) main rotor servo was still connected, and no significant damage was noted. The right (yellow) main rotor servo mount support, which allowed the mounting of the servo to the main gear box, was broken, consistent with shear/tensile overload. The actuator was otherwise undamaged. The left (red) main rotor servo mount support exhibited similar damage to the right support. Both rotating and fixed scissors on the main rotor head were normal in appearance. Three out of four main rotor dampers were disconnected from their respective blades consistent with overload damage. The white blade damper was still connected.
The collective grip was examined. The engine governor switch was on Mec (mechanical governor mode). The throttle selector was on Man (manual), and the throttle position was between Idle and Flt (flight). Freedom of movement of the throttle was verified from Max to Idle. The throttle could be moved to Stop by lowering the spring-loaded collar; however, it bounced back to Idle if released, indicating possible mechanical damage. The collective moved freely between Mpog (minimum pitch on ground) and full up. Continuity of the Teleflex cable connecting the throttle grip with the engine fuel control unit was positively verified, although it was not possible to physically access the front of the engine itself.
Freedom of movement of the cyclic grip was verified both laterally and longitudinally.
The No. 1 hydraulic reservoir was empty; the No. 2 reservoir still retained a low level of fluid. After the crash a large leak developed inside the cabin compartment, with traces of red fluid visible on the cabin ceiling near the crack. The lack of fluid was consistent with the post-accident damage.
The examination of the airframe did not reveal any evidence of a preexisting malfunction or failure that would have precluded normal operation. All damage noted was consistent with ground impact.
According to the operator, the pilot had 31.4 hours of NVG time, with no experience in NVGs prior to his employment there. He first qualified on NVGs on May 3, 2024, and his most recent currency flights on NVGs occurred on August 23 and 25, 2024, and September 16, 2024.
On the day of the accident, sunset occurred at 1911 and dusk was at 1939. At the time of the accident, the sun was 10.38° below the horizon at an azimuth of 281.11°. The moon rose at 1958 and was 0.34° above the horizon at an azimuth of 75.77°. Moon illumination was 94.6%; Waning Gibbous phase.