The NTSB is faulting the pilot of a Bell 206 that crashed into New York’s East River in 2011, killing three of the four passengers after it experienced an apparent loss of tail rotor effectiveness (LTE).
The pilot, operating a Part 91 VFR flight, landed at the East 34th Street helipad and hot-loaded four passengers without performing weight and balance calculations or conducting a safety briefing. The NTSB found that the helicopter was likely overweight between 28 and 261 pounds and that the pilot performed a rearward hover departure with a pedal turn into the wind that increased his risk of encountering LTE. He subsequently lost control of the helicopter while transitioning between in-ground and out-of-ground effect hover and spun it into the East River from an altitude of approximately 60 feet above the water. The helicopter rolled over and sank. One back seat passenger died at the scene while the other two later died of injuries relating to near-drowning. The pilot and the front seat passenger survived.
The NTSB noted that the FAA warned of this condition in February 1995 (“Unanticipated Right Yaw in Helicopters,” AC 90-95): “Any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur.”
The NTSB noted that when operating at airspeeds below effective transitional lift, pilots should avoid OGE hover and high power demand situations, such as low-speed downwind turns. “Contributing factors for LTE included high gross weight, low indicated airspeed and right downwind turns. Thus, it is likely that the helicopter experienced LTE shortly after takeoff because all of these factors were present at the time of the accident.”
The NTSB found the accident’s probable cause was, “The pilot’s failure to anticipate and correct for conditions conducive to loss of tail rotor effectiveness, which resulted in LTE and in an uncontrolled spin. Contributing to the accident was “the pilot’s inadequate preflight planning, which resulted in the helicopter being in excess of its maximum allowable gross weight at takeoff.”