NTSB Factual Report

On July 21, 2017, at 1211 Pacific daylight time, a Robinson R44 II, N3254E, landed hard following an autorotation near Van Nuys Airport, Van Nuys, California. The helicopter was registered to and operated by National Helicopter Service and Engineering Company, as a 14 Code of Federal Regulations Part 91 revenue sightseeing flight . The flight instructor and three passengers sustained serious injuries, and the helicopter sustained substantial damage during the landing. The local flight departed Van Nuys about 1112. Visual meteorological conditions prevailed and no flight plan had been filed.

The three passengers and pilot boarded the helicopter at 1100 for what was to be a 1-hour tour around the Los Angeles area. The pilot reported that the tour was uneventful, and as they approached the airport for landing he heard an unusual sound. He glanced down at the engine tachometer, and it was higher than normal, indicating above 110%. About that time a passenger exclaimed that he could see a low rotor RPM warning light.

The pilot began manipulating the engine throttle to reduce power, and the rotor RPM began to drop. He continued to manipulate the collective and throttle controls, but the helicopter would not maintain altitude, and concluding that he could not make it back to the airport, he initiated an autorotation into a street below.

He stated that trees and power poles blocked his landing approach, and as such he did not have sufficient speed or space to perform an adequate flare, and the helicopter landed hard.

The helicopter came to rest on a street, in between the Los Angeles River and Highway 101, about 3 miles southeast of the approach end of runway 34L. The landing skids had splayed level with the belly during the impact, and the pop-out floats had deployed. The entire airframe exhibited buckling damage, and the belly was crushed. The tail rotor gearbox struck a fence, and had partially detached, and both main rotor blades remained attached to the mast, but had folded downwards.