Saturday, June 2, 2018

Cessna LC41-550FG, N932AC: Incident occurred December 08, 2015 on Naval Weapons Station Seal Beach, Orange County, California

The National Transportation Safety Board did not travel to the scene of this incident.

Additional Participating Entity;
Continental Motors Inc; Mobile, Alabama 

Aviation Incident Factual Report - National Transportation Safety Board:  https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board:  https://dms.ntsb.gov/pubdms

http://registry.faa.gov/N932AC


Location: Seal Beach, CA
Incident Number: WPR16IA044
Date & Time: 12/08/2015, 0850 PST
Registration: N932AC
Aircraft: CESSNA AIRCRAFT CO LC41-550FG
Aircraft Damage: Minor
Defining Event: Loss of engine power (total)
Injuries: 2 None
Flight Conducted Under: Part 91: General Aviation - Personal 

On December 8, 2015, at 0850 Pacific standard time, a Cessna LC41-550FG airplane, N932AC, experienced a total loss of engine power and forced landed on open terrain on Naval Weapons Station Seal Beach, Seal Beach, California. The airplane sustained minor damage and the commercial pilot was not injured. The airplane was registered to Sotto International, Inc., and operated by the pilot as a Title 14 Code of Federal Regulations Part 91, personal flight. Visual meteorological conditions prevailed for the flight. The flight originated from San Diego, California, about 0830, and was destined for Long Beach, California.

The pilot reported to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), that the engine started "missing" [running rough] just after departure but he corrected the condition by leaning the mixture. While in cruise the engine started "missing" again but smoothed out after he turned towards a nearby airport, at which point he decided to continue to his destination. When approximately 4 miles away from his destination the engine started to miss then quit. The pilot made a forced landing in an open area on the Naval Weapons Station Seal Beach facility. The pilot stated that he did not perform a magneto check at any time after the engine began running rough.

The airplane was ground transported to a fixed base operator located at the Long Beach Airport. The airplane and engine were examined by an airframe and power plant mechanic who reported that there was no external damage to the engine or propeller, and that the right magneto had gear teeth missing. The magneto timing of the left magneto was confirmed correct. The NTSB IIC took possession of the two magnetos. The SD memory card that normally records engine performance data was not installed in the primary flight display at the time of the incident.

The magnetos were examined at Continental Motors, Mobile, Alabama, on April 12, 2016, under the supervision of the NTSB IIC. Both magnetos were tested on a magneto test bench followed by a teardown examination. The left magneto, serial number D07OA109, bench test demonstrated spark at all distributor leads throughout the normal operating range. When the magneto was disassembled brass colored dust covered the interior of the distributor. The inspection determined that the gear washer and nylon washer had been installed in reverse order resulting in rapid bushing wear excessive radial play in the distributor drive gear. The excessive radial play of the gear had the potential to cause the internal timing to migrate. The right magneto, serial number D08BA119, bench test demonstrated sparks on the numbers 6 and 3 leads only. When the magneto was disassembled it was determined that the distributor gear had sequentially shed 12 teeth.

A review of the airframe and engine maintenance records revealed that the most recent annual inspection was on July 15, 2015, at an airframe total time of 942 hours. Both magnetos were removed for a 500-hour inspection on June 8, 2012, at airframe total time of 566.6 hours. Both magnetos were overhauled and then placed back on to the engine. On March 1, 2014, at airframe total time 705 hours, an engine logbook entry stated "REMOVED AND REPLACED THE RH MAG FOR OVERHAUL. SEE AERO ACC 8130 DATED 1/2/2014." However, the Aero Accessories 8130 for the right-hand magneto, serial number D08BA11, was dated 21 March 2014. An entry in the airplane's Propeller Maintenance Logbook, dated 12/16/2014, stated "Removed left magneto and replaced with overhauled magneto. All work done IAW Cessna Maintenance Manual. See enclosed form 8130-3." No FAA Form 8130-3 for the left-hand magneto, serial number D07OA109, was located in the maintenance records.

NTSB Materials Laboratory Examination

The right-hand magneto distributor gear was sent to the NTSB Materials Laboratory for examination. The distributor gear was examined visually and under an optical stereo microscope. The teeth showed accumulations of dark-colored grease on both the contact and non-contact faces. Metallic orange flakes were also observed within the grease. Twelve teeth were fractured, and the remaining teeth were intact with no cracks detected.

Tooth fractures had been initiated at both the contact and the noncontact sides of the teeth. A close view of the fracture surfaces features generally showed a relatively smooth area at the fracture initiation side of the tooth covering approximately 1/4 to 1/2 of the fracture area. Curving lines representing the fracture front were observed at the boundary of the smooth area. Raised hackle features and multiple curving crack front lines were present between the smooth area and the fracture termination. The lab was able to replicate the fracture characteristics by impacting an intact gear tooth with a chisel and hammer.

Additional Information

Australian Civil Aviation Safety Authority Airworthiness Bulletin (AWB) 17-005, Issue 3, dated October 20, 2014, lists numerous potential causes for nylon distributor gear failures, including propeller strikes, kickback during starting before fire events, and any other event that can cause shock on the gear train driving the distributor gear.

Columbia 400 Pilot's Operating Handbook, Section 3-24 (extract)

"Engine Roughness – The most common cause of a rough running engine is an improper mixture setting. Adjust the mixture in reference to the power setting and altitude in use. Do not immediately go to a full rich setting since the roughness may be caused by too rich of a mixture. Do not immediately go to a full rich setting since the roughness may be caused by too rich of a mixture. If adjusting the mixture does not correct the problem, reduce throttle until roughness becomes minimal, and perform a magneto check."

"Check operations on the individual left and right magnetos. If the engine operates smoothly when operating on an individual magneto, adjust power as necessary and continue. However, do not operate the engine in this manner any longer than necessary. Land as soon as possible for determination and repair of the problem. If individual magneto operations do not improve performance, set the magneto switch to R/L, and land as soon as possible for engine repairs." 

Pilot Information

Certificate: Commercial
Age: 54, Male
Airplane Rating(s): Multi-engine Land; Single-engine Land
Seat Occupied: Left
Other Aircraft Rating(s): Helicopter
Restraint Used: Lap Only
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): Airplane Multi-engine; Instrument Airplane
Toxicology Performed: No
Medical Certification: Class 2 Without Waivers/Limitations
Last FAA Medical Exam: 08/16/2015
Occupational Pilot:
Last Flight Review or Equivalent:
Flight Time:  3774 hours (Total, all aircraft), 352 hours (Total, this make and model), 3840 hours (Pilot In Command, all aircraft), 30 hours (Last 90 days, all aircraft), 10 hours (Last 30 days, all aircraft), 8 hours (Last 24 hours, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Manufacturer: CESSNA AIRCRAFT CO
Registration: N932AC
Model/Series: LC41-550FG UNDESIGNATED
Aircraft Category: Airplane
Year of Manufacture: 2008
Amateur Built: No
Airworthiness Certificate: Utility
Serial Number: 411021
Landing Gear Type: Tricycle
Seats: 4
Date/Type of Last Inspection:  07/15/2015, Annual
Certified Max Gross Wt.: 3600 lbs
Time Since Last Inspection: 85 Hours
Engines: 1 Reciprocating
Airframe Total Time: 1027 Hours at time of accident
Engine Manufacturer: CONT MOTOR
ELT: Installed, not activated
Engine Model/Series: TSIO-550-C
Registered Owner: SOTTO INTERNATIONAL INC
Rated Power: 310 hp
Operator: On file
Operating Certificate(s) Held: None 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KLGB, 60 ft msl
Observation Time: 0858 UTC
Distance from Accident Site: 6 Nautical Miles
Direction from Accident Site: 307°
Lowest Cloud Condition: Clear
Temperature/Dew Point: 17°C / 6°C
Lowest Ceiling: None
Visibility: 10 Miles
Wind Speed/Gusts, Direction: Calm
Visibility (RVR):
Altimeter Setting: 30.09 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: San Diego, CA (KMYG)
Type of Flight Plan Filed: VFR
Destination: Long Beach, CA (KLGB)
Type of Clearance: VFR
Departure Time: 0830 PST
Type of Airspace: Class E

Wreckage and Impact Information

Crew Injuries: 1 None
Aircraft Damage: Minor
Passenger Injuries: 1 None
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 None
Latitude, Longitude: 33.755000, -118.058889 (est)

NTSB Identification: WPR16IA044 
14 CFR Part 91: General Aviation
Incident occurred Tuesday, December 08, 2015 in Seal Beach, CA
Aircraft: CESSNA AIRCRAFT CO LC41-550FG, registration: N932AC
Injuries: 1 Uninjured.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.

On December 8, 2015, at 0850 Pacific standard time, a Cessna LC41-550FG airplane, N932AC, experienced a total loss of engine power and forced landed in open terrain on Naval Weapons Station Seal Beach, Seal Beach, California. The airplane sustained minor damage and the commercial pilot was not injured. The airplane was registered to Sotto International, Inc., and operated under 14 Code of Federal Regulations Part 91, as a visual flight rules flight. Visual meteorological conditions prevailed for the flight. The flight originated from San Diego, California, about 0830, and was destined to Long Beach, California.

The pilot reported to the NTSB investigator-in-charge, that the engine started "missing" (running rough) just after departure but he corrected the condition by leaning the mixture. While in cruise the engine started "missing" again but smoothed out after he turned towards a nearby airport, at which point he decided to continue to his destination. When approximately 4 miles away from his destination the engine started to miss then quit. The pilot made a forced landing in an open area on the Naval Weapons Station Seal Beach facility.

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