N78BR

Substantial
None

BELL 206B3S/N: 4001

Accident Details

Date
Saturday, January 15, 2011
NTSB Number
WPR11CA101
Location
Three Forks, MT
Event ID
20110118X03801
Coordinates
45.875000, -111.573333
Aircraft Damage
Substantial
Highest Injury
None
Fatalities
0
Serious Injuries
0
Minor Injuries
0
Uninjured
2
Total Aboard
2

Probable Cause and Findings

The pilot’s inadequate use of throttle during the practice autorotation that resulted in a hard landing.

Aircraft Information

Registration
Make
BELL
Serial Number
4001
Engine Type
Turbo-shaft
Year Built
1988
Model / ICAO
206B3B06
Aircraft Type
Rotorcraft
No. of Engines
1
Seats
5
FAA Model
206B

Registered Owner (Current)

Name
MONTANA AIR TANKERS LLC
Address
1680 AIRPORT RD
City
THREE FORKS
State / Zip Code
MT 59752-9085
Country
United States

Analysis

The pilot practiced several maneuvers, and then entered a straight-in practice autorotation. He pointed the helicopter into the wind at 800 feet above ground level (agl) near midfield and above the runway. He rolled the throttle to flight idle, and lowered the collective while gently flaring the nose of the helicopter to set up the appropriate main rotor revolutions per minute (rpm) and airspeed. He monitored those parameters carefully during the descent, and noted that they remained well within the normal range. At the bottom of the descent, the pilot flared a little high to allow a margin of safety for tail boom clearance as he was planning a power recovery from the autorotation. However, the pilot stated that he did not add power at that point, and there was inadequate rotor inertia to dampen the landing, even though he applied full collective deflection. The helicopter hit hard, and sustained substantial damage. The aft portion of the tail boom and tail rotor separated due to a main rotor blade contact, and the skids were damaged. The pilot performed an emergency shut down; he closed the throttle, and switched off the battery, generator, and fuel valve. After exiting the helicopter he secured the battery.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# WPR11CA101