LAX08LA142

NTSB accident investigation · Ercoupe 415-C · Penngrove, CA · May 15, 2008

Accident · No injuriesLimited investigationFinal report
Date
May 15, 2008, 15:10 local (22:10 UTC)
Place
Penngrove, CA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N99180Ercoupe 415-C
Defining event
Enroute-cruise: Loss of engine power (total)
Weather
Visual (VMC) · Day
Status
Completed · report August 28, 2008
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20080515835839A
Case key
68021

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The loss of engine power resulting from frayed magneto "P" leads, which shorted out and killed the ignition system. Contributing to the accident was the lack of suitable terrain for the forced landing.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Inspection: scheduled/routine inspectionPersonnel issues › Task performance · Maintenance personnelErcoupe 415-C: 1 caseAll aircraft: 167 casesProbable cause
TerrainEnvironmental issues › Physical environment · Not specifiedErcoupe 415-C: 2 casesAll aircraft: 267 casesProbable cause
Ignition system: ignition power supplyAircraft › Aircraft power plant · Damaged/degradedErcoupe 415-C: 1 caseAll aircraft: 13 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

During cruise flight, the airplane's engine lost total power and the pilot executed a forced landing in an alfalfa field. During the landing roll in the 2 to 3-foot-tall grass, the airplane skidded sideways and the tail dug into the ground. The airplane's tail cone was buckled, and the right vertical stabilizer and rudder were bent. Federal Aviation Administration (FAA) inspectors found that both magnetos had frayed primary wires ("P" leads) at the magnetos, which could have been shorting out and intermittently killing the ignition system. They noted numerous additional maintenance discrepancies with the airplane; however, none of these would have contributed to a loss of engine power. According to the inspectors, the airplane's most recent annual inspection was completed about 2 months before the accident. The maintenance discrepancies found by the FAA inspectors, including the frayed "P" leads, should have been repaired during this annual inspection.

Factual narrative

On May 15, 2008, about 1510 Pacific daylight time, an Ercoupe 415-C, N99180, sustained substantial damage during a forced landing following a loss of engine power in Penngrove, California. The sport pilot and his passenger were not injured. The airplane was being operated by the pilot under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The local personal flight departed from the Petaluma Municipal Airport, Petaluma, California, about 1450. According to Sonoma County Sheriff's Department personnel, the pilot reported that while in cruise flight he noticed the oil pressure gauge begin to fluctuate erratically. The needle on the gauge "began to bounce up and down," and seconds later, the engine "began to cut out and sputter." The pilot headed back towards Petaluma Airport. However, the engine lost total power, and the pilot executed a forced landing in an alfalfa field about 4.5 miles northwest of the airport. During the landing roll in the 2- to 3-foot-tall grass, the airplane skidded sideways and the tail dug into the ground. The airplane's tail cone was buckled, and the right vertical stabilizer and rudder were bent. The airplane was examined by Federal Aviation Administration (FAA) inspectors. The inspectors found that both magnetos had frayed primary wires ("P" leads) at the magnetos, which could have been shorting out and intermittently killing the ignition system. They noted numerous additional maintenance discrepancies with the airplane; however, none of these would have contributed to a loss of engine power. According to the inspectors, the airplane's most recent annual inspection was completed on March 19, 2008.

Aircraft

Registration
N99180
Reported as
Ercoupe 415-C
Category
Airplane
Serial number
1803
Engine
Continental O-200-A, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Anthony J. Toni
Registered owner
James C. Grimes
Airworthiness certificate
Standard, Normal
Last inspection
Annual · March 1, 2008
Departed
O69 · Petaluma, CA
Destination
O69

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
54
Injuries
None
Certificate
Sport Pilot
Airplane ratings
Single-engine land
Medical
Sport pilot
Last flight review
February 1, 2007
Seat
Left
Flight hours
4,300 total · 66 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
95 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.