Aircraft Accident/Incident Report

Big Bear Lake, California 92315
Tuesady, November 14, 2006 10:13 PST

NTSB Narrative Summary Released at Completion of Accident

Witnesses said that it appeared that the left engine sustained a loss of power just after rotation and liftoff. The airplane initially had a positive rate of climb, but then immediately yawed to the left as it cleared 30-foot-high power lines that were perpendicular across the flight path. The airport is at the east end of a lake in a mountain valley; the airplane departed to the west and was flying over the lake. The airplane was about 2 miles from the runway when witnesses observed dark smoke coming from the left engine, and the smoke increased significantly as the flight continued. The airplane banked hard left with the wings perpendicular to the ground, and then nosed in vertically. The landing gear remained down throughout the accident sequence. On site examination revealed that the top spark plugs for the left engine were black and sooty. A detailed examination revealed that the left turbocharger turbine wheel shaft fractured and separated. Extreme oxidation of the fracture surfaces prevented identification of the failure mode; however, the oxidation was the result of high temperature exposure indicating that the fracture occurred while the turbocharger was at elevated temperature during operation. The multiple planes exhibited by the fracture also were not consistent with a ductile torsional failure as would be expected from a sudden stoppage of either rotor. No evidence of a mechanical malfunction was noted to the right engine. The Cessna Owners Manual for the airplane notes that the most critical time for an engine failure is a 2-3 second period late in the takeoff while the airplane is accelerating from the minimum single-engine control speed of 87 KIAS to a safe single-engine speed of 106 KIAS. Although the airplane is controllable at the minimum control speed, the airplane's performance is so far below optimum that continued flight near the ground is improbable. Once 106 KIAS is achieved, altitude can more easily be maintained while the pilot retracts the landing gear and feathers the propeller. The best single-engine rate-of-climb is 108 KIAS with flaps up below 18,000 feet msl. Section VI of the manual provides operational data for single-engine climb capability. The data was only valid for the following conditions: gear and flaps retracted, inoperative propeller feathered, wing banked 5 degrees toward the operating engine, 39.5 inches of manifold pressure if below 18,000 feet, and mixture at recommended fuel flow.

NTSB Probable Cause Narrative

Failure of the turbine wheel shaft in the left turbocharger during the takeoff initial climb for undetermined reasons, and the pilot's failure to attain and maintain safe single engine airspeed that led to a loss of control.

Event Information

Type of Event Accident
Event Date 11/14/2006
Event Day of the Week Tuesday
Time of Event 1013
Event Time Zone Pacific Standard Time
Event City Big Bear Lake
Event State CALIFORNIA
Event Country --
Zipcode of the event site 92315
Event Date Year 2006
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 341426N
Event Location Longitude 1165635W
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 8
Degrees magnetic from airport --
Airport Elevation 6752
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 955 Pacific Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID KL35
Elevation of weather observation facility 6752
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation PDT
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) 13
Dew Point at event time (in degress fahrenheit) -1
Wind Direction (degrees magnetic) 250
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 13
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 24
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 3
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 24290
NTSB Notification Source FAA
NTSB Notification Date Nov 14 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Sep 26 2008 6:40PM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office FSDO - Riverside, CA

Aircraft Involved

Aircraft #1

Aircraft Registration Number N642BD
NTSB Number LAX07FA035
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 421B
Aircraft Series Identifier --
Aircraft Serial Number 421B0658
Certified Max Gross Weight --
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 8
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection May 1 2006 12:00AM
Airframe hours since last inspection --
Airframe Hours 4556
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Robert F Cartwright
Aircraft Owner Street Address --
Aircraft Owner City Sugarloaf
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 92386
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
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) Executive/Corporate
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code L35
Departure City Big Bear Lake
Departure State CA
Departure Country USA
Departure Time 1000
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code KLAS
Destination City Las Vegas
Destination State NV
Destination Country USA
Specific Phase of Flight Takeoff - initial climb
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 9 2008 4:51PM
User who most recently changed record COOS
Since inspection or accident Last Inspection
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --