WPR20LA295

NTSB accident investigation · Beech 35 · Three Rivers, CA · September 4, 2020

Accident · FatalClass 3 · LimitedFinal report
Date
September 4, 2020, 11:48 local (18:48 UTC)
Place
Three Rivers, CA
Injuries
2 fatal
Damage
Destroyed
Phase of flight
Enroute
Aircraft
N818SBeech 35
Defining event
Enroute-cruise: Controlled flight into terr/obj (CFIT)
Weather
Instrument (IMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FSDO, Textron Aviation
FAA report
20200904016619A
Case key
101919

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 controlled flight into terrain while operating in conditions of reduced visibility due to smoke.

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.

Ceiling/visibility/precip: haze/smokeEnvironmental issues › Conditions/weather/phenomena · Contributed to outcomeBeech V35B: 1 caseAll aircraft: 21 casesProbable cause
Performance/control parameters: altitudeAircraft › Aircraft oper/perf/capability · Not attained/maintainedBeech V35B: 4 casesAll aircraft: 1,310 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 pilot and passenger departed on a visual flight rules cross-country flight into an area of reduced visibility due to wildfire smoke. An alert notice was issued when the airplane did not arrive at the destination, and the wreckage was located the following day in mountainous terrain at an elevation about 9,500 ft mean sea level. No anomalies were noted with the airplane during post-accident examination. Impact signatures and wreckage dispersion were consistent with the pilot’s controlled flight into terrain while operating in conditions of reduced visibility due to smoke.

Factual narrative

On September 4, 2020, about 1148 Pacific daylight time, a Beechcraft 35 airplane, N818S, was destroyed when it was involved in an accident near Three Rivers, California. The pilot and passenger sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The Federal Aviation Administration issued an alert notice (ALNOT) for the airplane after family members reported the airplane missing. Radar data depicted a primary target consistent with the accident airplane depart Visalia Municipal Airport (VIS), Visalia, California, about 1125 and fly east on the visual flight rules non-discreet transponder code. The airplane flew toward rising terrain south of Silver City, California, and the last recorded radar target was about 1148. The wreckage was discovered on September 5, 2020, in mountainous terrain at an elevation of approximately 9,500 feet mean sea level (msl), on top of a small plateau with large pine trees and large boulders. The airplane was destroyed, and portions of the wreckage were consumed by post impact fire. The wreckage was dispersed along a path about 160 ft long. The wreckage was recovered and examined at a secure location. The wreckage was highly fragmented and thermally damaged. The cabin from the cockpit seats to the firewall were mostly consumed by fire. The side and upper cabin skins from the baggage compartment forward were consumed by fire. The wings were fractured into multiple segments. The majority of the right wing was consumed by fire. Portions of the wing spar remained. The wing tip fuel tanks sustained thermal damage. The stabilizers and elevators were impact separated from the tail. The inboard portion of the left stabilizer exhibited an 18-inch circular tree impact impression perpendicular to the stabilizer chord line. The right stabilizer was unremarkable. Both sustained slight thermal damage to the paint finish. Flight control cable continuity could not be established due to fragmentation and extensive thermal damage to the cockpit area. The engine and all observed components exhibited fire damage, corrosion, and some impact damage. All three propeller blades were attached to the propeller hub, which remained attached to the engine. Each propeller blade exhibited leading edge gouging and S-type bending. Both turbocharger units were partially impact separated from the engine and exhibited impact and heat damage. Attempts to verify engine continuity, valve train continuity, and cylinder compression by rotating the engine were unsuccessful. Visual confirmation of engine continuity was made using a borescope. No anomalies were noted with the engine or examined components. The National Weather Service produced a spot forecast for the approximate area of the accident site on the day of the accident. The forecast indicated sunny skies with areas of smoke and haze from the SQF Complex Fire. Stable air conditions continued to keep smoke in the valleys. Kern RiverValley was impacted by unhealthy to hazardous air quality.

Aircraft

Registration
N818S
Reported as
Beech 35 (V35B)
Category
Airplane
Serial number
D-9101
Built
1970
Airframe hours
2,566
Engine
Continental TSIO-520-D, 285 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Operator
Nepinsky Brian C
Registered owner
Nepinsky Brian C
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 22, 2020
Departed
KVIS · Visalia, CA
Destination
KEED · Needles, CA

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot-rated passenger
Age
45
Injuries
Fatal
Certificate
Private
Airplane ratings
Single-engine land
Medical
Unknown
Toxicology
Performed
Flight hours
630 total
Role
Pilot
Age
82
Certificates
Airline transport, Commercial
Airplane ratings
Single-engine sea, Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Unknown
Flight hours
38,000 total

Weather

Conditions
Instrument (IMC) · Day
Wind
260° at 5 knots
Visibility
8 statute miles
Temperature
90 °F, dew point 55 °F
Altimeter
29.96 inHg
Observed at
PTV, 31 nm away

Docket · 9

The files NTSB released with the investigation on July 7, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 15.0 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.