ERA18LA020

The pilot, flight nurse, and flight paramedic were conducting a flight for a public relations event. None of the three crewmembers had previously landed at this landing zone (LZ). A company flight nurse was on the ground at the LZ informing the flight crew of obstacles in the area. The pilot conducted a low reconnaissance and initiated a steep approach into the LZ. All obstacles were observed and called out by crewmembers as they continued the approach. The terrain appeared to the crew to be flat in all directions. The pilot began to set the helicopter on the ground from a stabilized hover. As the pilot lowered the collective to set the skids on the ground, the skid toes and the forward half of the skids made ground contact; however, from just aft of the pilot’s seat, the terrain sloped downward at a 10°-to-15° angle. Once the collective was lowered to the bottom stop, the helicopter rocked backwards to a tail-low attitude. The pilot and crew felt the tail stinger make ground contact and assumed that the tail rotor had impacted the ground. The pilot then applied upward collective and forward cyclic, which forced the front of the skid toes tightly against the terrain. The application of upward collective resulted in the helicopter entering an incipient dynamic rollover, aggressively rolling to a 45°-to-60° nose-low attitude. The pilot applied aft cyclic to counter the nose low attitude, and mast bumping occurred when the droop (static) stops came in to contact with the mast. The main rotor then separated from the mast and departed the helicopter. The circumstances of the accident are consistent with the pilot’s attempted recovery following a slope landing, which resulted in incipient dynamic rollover, mast bumping, and separation of the main rotor.

On November 8, 2017, about 1140 central standard time, a Bell 206L-3 helicopter, N275AE, was substantially damaged when it was involved in an accident in Union City, Tennessee. The pilot, flight nurse, and flight paramedic sustained minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 positioning flight. The helicopter, operated by Air Evac EMS Inc, departed for a public relations event at the Obion County Emergency Communications District 911 Center. The pilot was shown the requested landing zone (LZ), which was across the street from the center next to a church, and was instructed to land where other pilots had previously landed. A company employee located at the LZ had a portable radio programmed to the company channel. Upon his arrival at the LZ, he notified the crew of the helicopter that the LZ was secure and asked them to launch at 1124. About 1135, he heard the pilot transmit his flight plan. About 3 minutes later, the helicopter flew over the LZ. The company employee transmitted that he was directly underneath them and asked if they saw his red truck, located where the helicopter was supposed to land; however, he did not receive a response. He observed the helicopter flying a high and low reconnaissance utilizing left hand turns and watched the helicopter turn for final approach to the church parking lot, adjacent to where he was located. He advised the pilot over the radio that the helicopter was clear of wires and again received no response. The helicopter descended onto a steep grassy slope, catching the front third of the skid on top of the slope. As more weight was placed on the skids, the tail boom rapidly descended toward the ground and the stinger embedded into soft mud close to an asphalt driveway. The company employee thought he observed the tail rotor strike the mud. At this point, the sound of the engine changed, and the tail boom rose into the air at what the company employee estimated to be 60°. There was an "explosively loud bang" and the airframe slammed violently back down onto the slope. At this point, the helicopter began to shake violently from left to right, and the main rotor separated from the mast. The pilot reported that he was unfamiliar with the LZ and had discussed the area with the company employee, who described to him where there were powerlines along the road bordering the LZ and showed him where other pilots had landed in the past. He also thought he understood him to say that the parking lot at the LZ could be used as well. As he approached the LZ, he made radio contact with the company employee, who advised that the LZ was clear. He performed a low reconnaissance and determined that the best approach would be to the northwest. On final approach, he called out trees to the flight paramedic and wires along the road to the flight nurse. When he was on short final, the flight paramedic called out clear of trees, and wires mid-skid. A brief time later, the flightnurse and flight paramedic both called clear of wires and clear to come down. Due to the steep approach he had performed to clear the trees and wires, the pilot decided to land in the parking lot. As he moved toward the lot, electrical wires running from poles on the lot came into view. He called out wires, stopped, and decided he could land on the grass just south of the lot. As the helicopter settled to the ground, he felt the skids touch down and began to lower the collective. The helicopter’s tail continued to fall, and he increased collective to stabilize it; but, the tail continued downward, and he felt the helicopter sliding backwards. He added more collective and felt two "thumps." Thinking that his tail rotor had contacted something, he added forward cyclic and began to reduce power. The tail of the helicopter rose rapidly. He then applied aft cyclic, and the tail came back down. The helicopter began shaking violently and rocking back and forth. He shut off the fuel, the helicopter came to a stop, and the occupants egressed. Examination of the accident site revealed that the helicopter touched down on level ground with the front portion of the skids; however, just aft of the pilot’s seat, the ground sloped down about 10° to 15°. Ground scars from the skids and lower wire strike assembly were present, which coincided with the position of the helicopter’s nose and touchdown point. A ground scar was also present, which coincided with the position of the tail stinger. After striking wires, the main rotor traveled across the street and came to rest on the lawn of the county emergency communications center. Examination of the helicopter revealed that the main rotor had separated from the main rotor shaft just below the rotor head, and the droop (static) stops had been damaged. The fairing over the transmission was crushed and broken, the tail stinger was bent upwards, and the upper tail fin was bent to the right. The tail boom was also bent to the right and almost completely separated just aft of the cabin area. The rear crossover tube for the landing skids was bent, and the crossover tube was pushed up into the right side of the lower fuselage. Both windscreens were broken.