WPR14LA230

NTSB accident investigation · Cessna 172M · Laytonville, CA · June 6, 2014

Accident · FatalLimited investigationFinal report
Date
June 5, 2014, 19:23 local (Jun 6, 2014, 02:23 UTC)
Place
Laytonville, CA
Injuries
1 fatal
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N1186UCessna 172M
Defining event
Maneuvering-low-alt flying: Low altitude operation/event
Weather
Visual (VMC) · Day
Status
Completed · report September 14, 2016
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Lycoming Engines, Textron Aviation, FAA
FAA report
20140605008829A
Case key
89372

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

On this page

Probable cause

The pilot’s impairment due to alcohol ingestion, which resulted in his failure to maintain clearance from trees during a low-altitude flyby.

Findings · 4

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.

Impairment/incapacitation: alcoholPersonnel issues › Physical · PilotCessna 172M: 1 caseAll aircraft: 87 casesProbable cause
Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedCessna 172M: 17 casesAll aircraft: 1,310 casesProbable cause
Object/animal/substance: tree(s)Environmental issues › Physical environment · Awareness of conditionCessna 172M: 16 casesAll aircraft: 933 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

The private pilot was conducting a local personal flight. Witnesses reported that they observed the airplane making several low passes over an open field. During the last pass, they observed the airplane's right wing contact a tree and then separate from the airplane. The airplane subsequently came to rest in a wooded area. According to the autopsy report, the pilot had coronary artery maximum occlusion of 50 percent, and there was no evidence of preexisting heart muscle scarring. This amount of occlusion likely would not have caused acute symptoms and would not have impaired the pilot's judgment; therefore, the pilot's coronary artery disease likely did not impair his ability to operate the airplane or contribute to the accident. Toxicology reports identified ethanol in the pilot's heart blood, iliac blood, vitreous, and urine. The distribution of the ethanol in the pilot's tissue was consistent with ingestion, not postmortem production. Although there was some variation, all of the pilot's tissues tested positive for ethanol well above 0.040 gram per deciliter, which indicates that the pilot had ingested sufficient ethanol to impair his ability to safety operate the airplane.

Factual narrative

The airplane was a Cessna 172M, serial number 17266887. No logbooks were made available for examination. At the wreckage examination, the tachometer read 1,194.4, and the Hobbs hour meter read 890.5. The engine was a Lycoming O-360-A4A that had been altered to an O-360-A4M, serial number L-30908-36A. On June 5, 2014, about 1923 Pacific daylight time, a Cessna 172M, N1186U, collided with trees while maneuvering at low altitude near Laytonville, California. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot sustained fatal injuries. The airplane sustained substantial damage to the airframe and wings during the accident sequence. The local personal flight departed Laytonville at an undetermined time. Visual meteorological conditions (VMC) prevailed, and no flight plan had been filed. Witnesses reported that the airplane was at low level, and made several passes over an open field. During another pass, they observed the right wing make contact with a tree, and separate from the airplane. The airplane came to rest in a wooded area. A postmortem examination was conducted by the Office of the Coroner – Mendocino County. The cause of death was reported as the effect of blunt force injuries. The Coroner had specimens from the pilot tested by NMS Labs, Willow Grove, Pennsylvania. The toxicology test identified 217 mg/dL of ethanol in the iliac blood. The FAA Civil Aerospace Medical Institute Forensic Toxicology Research Team, Oklahoma City, performed toxicological testing of specimens of the pilot. Analysis of the specimens contained no findings for carbon monoxide or tested drugs. They did not perform tests for cyanide. The report contained the following findings for volatiles: 274 (mg/dL, mg/hg) ethanol detected in urine, 237 (mg/dL, mg/hg) ethanol detected in vitreous; and 172 (mg/dL, mg/hg) detected in blood (heart). An NTSB Medical Officer examined the pilot's medical records, and provided a factual report. The report is part of the public docket for this accident, which is accessible via a link on the ntsb.gov home page. On the most recent medical exam dated August 7, 2012, the pilot reported a history of a driving under the influence (DUI) arrest on March 22, 2012. The records indicated a previous alcohol related arrest in 1990. Ethanol is the intoxicant commonly found in beer, wine, and liquor; it acts as a central nervous system depressant. The distribution pattern parallels the water content and blood supply of each organ. Ethanol may also be produced in the body after death by microbial activity, but urine and vitreous are less prone to postmortem changes. After ingestion, at low doses it impairs judgment, psychomotor functioning, and vigilance; at higher doses it can cause coma and death. The effects of ethanol on aviators are generally well understood; it significantly impairs pilots' performance, even at very low levels. Federal Aviation Regulations, Section91.17 (a) prohibits any person from acting or attempting to act as a crewmember of a civil aircraft while having 0.040 gm/dL or more ethanol in the blood. The autopsy identified coronary artery disease with up to 40% narrowing of the proximal left anterior descending artery and diffuse 25 to 50% narrowing of the mid portion of the right coronary artery. It did not identify focal lesions the heart muscle. A review of Federal Aviation Administration (FAA) airman records revealed that the 63-year-old pilot held a private pilot certificate with a rating for airplane single-engine land. The pilot held a third-class medical certificate issued on August 7, 2012. It had the limitation that the pilot must have glasses for near vision. No personal flight records were located for the pilot. The National Transportation Safety Board (NTSB) investigator-in-charge (IIC) obtained the aeronautical experience listed in this report from a review of the FAA airmen medical records on file in the Airman and Medical Records Center located in Oklahoma City, Oklahoma. The pilot reported on his medical application that he had a total time of 590 hours with 0 hours logged in the previous 6 months. Investigators from the NTSB, the FAA, Cessna, and Lycoming examined the wreckage at Air Transport, Phoenix, Arizona, on July 16, 2014. A full report is in the public docket for this accident, which is accessible via a link on the ntsb.gov home page. The airframe and engine were examined with no mechanical anomalies identified.

Aircraft

Registration
N1186U
Reported as
Cessna 172M
Category
Airplane
Serial number
17266887
Built
1976
Engine
Lycoming O-360-A4M, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Gillespie Kenneth H Trustee
Registered owner
Gillespie Kenneth H Trustee
Airworthiness certificate
Standard, Normal
Departed
Laytonville, CA
Destination
Laytonville, CA
Equipment
Stall warning system

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
63
Injuries
Fatal
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Seat
Left
Restraint
3-point
Toxicology
Performed
Flight hours
590 total

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
91 °F, dew point 32 °F
Altimeter
29.73 inHg
Observed at
KUKI

Docket · 5

The files NTSB released with the investigation on June 28, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.8 MB in all.

FAA reports on this event · 1

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