Reedley Municipal Airport
Aircraft Accident/Incident Report

Lake Thomas A., California 93629
Friday, May 24, 2002 6:45 PDT

NTSB Narrative Summary Released at Completion of Accident

The airplane experienced a partial loss of engine power and collided with a tree stump during a precautionary landing on a beach. While climbing through 9,000 feet mean sea level (msl) the pilot leaned the airplane by relying solely on the exhaust gas temperature gauge. When reaching about 9,500 feet msl, about 1,500 feet above ground level over mountainous terrain, the pilot reported that the engine lost partial power. The propeller continued to turn, and the tachometer showed about 2,450 to 2,500 rpm, but the engine failed to produce enough power to sustain level flight. The pilot adjusted the mixture control, while also turning the carburetor heat to the on position, and applying full throttle. The engine failed to respond and the pilot made an approach to a sandy beach. The pilot flared the airplane about 2 feet above ground level, and the left wing collided with a tree stump, veering the airplane to the right. The elevation at the crash site was about 7,600 feet msl. A post accident investigation revealed that the left magneto exhibited excessive play at the cam end (points) of the main shaft. The subject magneto was later functionally tested, which revealed an intermittent spark on ignition lead T1. According to Textron Lycoming Mandatory Service Bulletin 515 the magnetos must be inspected every 500 hours. At the time of the accident, the magneto had accumulated a total time in service of 1,540.23 hours, and there was no maintenance entry indicating that the Service Bulletin had been complied with. While post accident tests showed that the left magneto was working only on an intermittent basis, information provided by Lycoming suggests that in and of itself the complete loss of one magneto would only result in a 3 to 5 percent loss of power. It is likely that the combined effects of the magneto malfunction, the high density altitude, and the pilot's manipulation of the mixture and carburetor heat all played roles in the engine's decreased performance capability.

NTSB Probable Cause Narrative

a partial loss of engine power due to the partial malfunction of the left magneto and leakage of the ignition leads for that magneto, due to inadequate maintenance inspections. Factors in the accident include the high density altitude, the maintenance personnel's failure to accomplish a service bulletin, and the effects of the pilot's manipulation of the mixture and carburetor heat controls.

Event Information

Type of Event Accident
Event Date 5/24/2002
Event Day of the Week Friday
Time of Event 645
Event Time Zone Pacific Daylight Time
Event City Lake Thomas A.
Event State CALIFORNIA
Event Country --
Zipcode of the event site 93629
Event Date Year 2002
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 372300N
Event Location Longitude 1190000W
Event Location Airport Reedley Municipal Airport
Event Location Nearest Airport ID O32
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 50
Degrees magnetic from airport 30
Airport Elevation 383
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 656 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 30
Weather Observation Facility ID KFAT
Elevation of weather observation facility 336
Distance of event from weather observation facility (units?) 50
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) 16
Dew Point at event time (in degress fahrenheit) 7
Wind Direction (degrees magnetic) 320
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 8
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.89
Density Altitude (feet) 607
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 2
Injury Total None --
Injury Total Serious 1
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 16319
NTSB Notification Source FAA
NTSB Notification Date May 24 2002 12:00AM
NTSB Notification Time 730
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Sep 29 2004 1:02PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office WP-FSDO-FRESNO, CA

Aircraft Involved

Aircraft #1

Aircraft Registration Number N79944
NTSB Number LAX02LA172
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 Cessna
Aircraft Model 172K
Aircraft Series Identifier --
Aircraft Serial Number 17258271
Certified Max Gross Weight 2300
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection May 16 2002 12:00AM
Airframe hours since last inspection 2.3
Airframe Hours 3676.9
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Bell Sky Pilots Inc.
Aircraft Owner Street Address 1188 S. Cyrier
Aircraft Owner City Reedley
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 93654
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) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code O32
Departure City Reedley
Departure State CA
Departure Country USA
Departure Time 620
Departure Time Zone PDT
Destination Same as Local Flt --
Destination Airport Code MLF
Destination City Milford
Destination State CO
Destination Country USA
Specific Phase of Flight Landing
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Jul 16 2004 6:15PM
User who most recently changed record COOS
Since inspection or accident --
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --