Aircraft Accident/Incident Report

Clarkson Valley, Missouri 63017
Friday, October 15, 2010 11:10 CDT

NTSB Narrative Summary Released at Completion of Accident

During the flight that preceded the accident flight, the pilot stated to one of the two officers aboard the helicopter that he would not be able to fly for as long as normal because he needed to obtain fuel. Upon completion of the observation flight, the pilot returned to the police department and shut down the helicopter to allow the two officers to exit. The pilot then restarted the helicopter and departed en route to an airport where he could refuel the helicopter. A witness near the accident site stated that he heard the helicopter’s engine sputter and stop and saw the main rotor separate from the helicopter. The helicopter entered an uncontrolled descent and impacted terrain. Postaccident examination of the helicopter revealed that there was no usable fuel on board and that the main rotor mast separated as a result of overload due to mast bumping (main rotor hub to rotor mast contact). No preimpact mechanical anomalies that would have precluded normal operation of the helicopter were noted. Mast bumping typically results from a low-G flight condition caused by the pilot pushing the cyclic control forward abruptly from either straight-and-level flight or after a climb. Pushing the cyclic forward abruptly is contrary to the appropriate actions for entering an autorotation, which are lowering the collective pitch control to the full down position, adding antitorque pedal as needed to maintain heading, and applying cyclic as needed to maintain proper airspeed. Review of the pilot’s medical records indicated that he had a history of depression, anxiety, and obstructive sleep apnea. Each of these conditions had been documented and treated since 2007, and none were reported to the Federal Aviation Administration (FAA) on the pilot’s airman medical application in 2010 or earlier. Any of these conditions may have disqualified the pilot from obtaining an airman’s medical certificate. Postmortem toxicological testing indicated that the pilot was taking alprazolam, an anti-anxiety medication, and venlafaxine, an anti-depressant. Alprazolam is one of a class of drugs which may worsen obstructive sleep apnea, and venlafaxine can cause fatigue and dizziness. The fact that the blood level of venlafaxine found was higher than normal therapeutic levels makes it more likely that the side effect of dizziness occurred and impaired the pilot’s performance.

NTSB Probable Cause Narrative

The total loss of engine power due to fuel exhaustion, which resulted from the pilot's inadequate preflight planning and decision-making, and his improper control inputs following the loss of engine power, which resulted in mast bumping and separation of the main rotor. Contributing to the accident was the pilot's improper judgment in acting as a pilot with disqualifying medical conditions.

Event Information

Type of Event Accident
Event Date 10/15/2010
Event Day of the Week Friday
Time of Event 1110
Event Time Zone Central Daylight Time
Event City Clarkson Valley
Event State MISSOURI
Event Country --
Zipcode of the event site 63017
Event Date Year 2010
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 383759N
Event Location Longitude 0903552W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1054 Central Daylight Time
Direction of event from weather observation facility (degrees) 315
Weather Observation Facility ID SUS
Elevation of weather observation facility 463
Distance of event from weather observation facility (units?) 3
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 17
Dew Point at event time (in degress fahrenheit) 3
Wind Direction (degrees magnetic) 350
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 3
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.13
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 29548
NTSB Notification Source FAA
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Feb 24 2012 12:41AM
User who most recently changed record snyg
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N96MP
NTSB Number CEN11GA020
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BELL
Aircraft Model 206B
Aircraft Series Identifier --
Aircraft Serial Number 3377
Certified Max Gross Weight 3200
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection May 7 2010 12:00AM
Airframe hours since last inspection 69
Airframe Hours 11254
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Street Address 1510 EAST ELM PO BOX 568
Aircraft Owner City JEFFERSON CITY
Aircraft Owner State MO
Aircraft Owner Country USA
Aircraft Owner Zipcode 65102
Operator is an individual? No
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 1510 EAST ELM PO BOX 568
Operator State MO
Operator Country USA
Operator Zip code 65102
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code --
Departure City Arnold
Departure State MO
Departure Country USA
Departure Time 1053
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code SUS
Destination City St. Louis
Destination State MO
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Dec 30 2011 1:24PM
User who most recently changed record galm
Since inspection or accident Time of Accident
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --