Summary
On February 18, 2020, a Aerospatiale AS350 (N188FS) was involved in an incident near Tampa, FL. All 2 people aboard were uninjured. The aircraft sustained substantial damage.
The National Transportation Safety Board determined the probable cause of this incident to be: The flight instructor's inadvertent throttle reduction below idle, which resulted in a total loss of engine power and subsequent impact with terrain following a power-off autorotation.
The flight instructor of the helicopter reported that, he directed the airplane rated pilot to conduct an autorotation with a 180° turn, followed with a power recovery. Abeam the departure end of runway, he moved the throttle lever from the FLY position to IDLE. While conducting the maneuver, the student pilot overshot the runway and aligned the helicopter with the parallel taxiway. Upon realizing the unacceptable position, they elected to abort the maneuver and perform a go-around. While the student pilot continued to fly the helicopter, the instructor inadvertently moved the throttle lever from IDLE, aft, towards the OFF position, then forward, to the FLY position. The engine experienced a total loss of power and the instructor adjusted the throttle to no avail.
This incident is documented in NTSB report ERA20CA106. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N188FS.
Accident Details
Probable Cause and Findings
The flight instructor's inadvertent throttle reduction below idle, which resulted in a total loss of engine power and subsequent impact with terrain following a power-off autorotation.
Aircraft Information
Registered Owner (Historical)
Analysis
The flight instructor of the helicopter reported that, he directed the airplane rated pilot to conduct an autorotation with a 180° turn, followed with a power recovery. Abeam the departure end of runway, he moved the throttle lever from the FLY position to IDLE. While conducting the maneuver, the student pilot overshot the runway and aligned the helicopter with the parallel taxiway. Upon realizing the unacceptable position, they elected to abort the maneuver and perform a go-around. While the student pilot continued to fly the helicopter, the instructor inadvertently moved the throttle lever from IDLE, aft, towards the OFF position, then forward, to the FLY position. The engine experienced a total loss of power and the instructor adjusted the throttle to no avail. As the helicopter continued the descent, the student pilot requested that the instructor "get on the controls". The instructor left the throttle in the full power position, took the controls and conduct a power-off autorotation. The helicopter landed on the taxiway, skidded about 180 feet, departed the taxiway, onto the adjacent grass and came to rest in a drainage ditch.The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
The Federal Aviation Administrator inspector who examined the helicopter at the accident site reported damage to the left anti-vibrator mount beam.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ERA20CA106