WPR23LA202

NTSB accident investigation · Mooney M-18C 55 · Napa, CA · May 26, 2023

Accident · Minor injuriesClass 3 · LimitedFinal report
Date
May 25, 2023, 18:46 local (May 26, 2023, 01:46 UTC)
Place
Napa, CA · open field
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N201MMMooney M-18C 55
Defining event
Approach: Fuel related
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FAA
FAA report
20230526008299A
Case key
192263

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 failure to use carburetor heat, which resulted in a loss of engine power due to carburetor icing and a subsequent impact with terrain during a forced landing.

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.

Action: lack of actionPersonnel issues › Action/decision · PilotMooney M-18C 55: 1 caseAll aircraft: 792 casesProbable cause
Ice/rain protection system: intake anti-ice, deiceAircraft › Aircraft systems · Not used/operatedMooney M-18C 55: 1 caseAll aircraft: 108 casesProbable cause
Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentMooney M-18C 55: 1 caseAll aircraft: 435 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 was on an approach to the airport about 3,000 ft above ground level (agl) when the engine lost all power. The pilot cycled the throttle control to full, but the engine did not restart and the propeller continued to windmill. He then declared an emergency and initiated a forced landing onto an open field about 5 miles north of the runway. During the landing roll on unimproved terrain, the left wing struck a large rock and came to rest nose down. Subsequently, the left wing sustained substantial damage. During recovery of the aircraft, about 20 gallons of fuel remained in its tanks; a postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies. The temperature at the airport, which was about 6 miles south of the accident site, was 63°F and the dew point was 52°F; the relative humidity was about 67%. A review of the icing probability chart contained within FAA Special Airworthiness Information Bulletin CE-09-35 revealed that the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power." The pilot added that he did not use carburetor heat during the descent and approach and that he should have used a pre-landing checklist.

Factual narrative

On May 25, 2023, about 1846 Pacific daylight time, a Mooney M-18C, N201MM, was substantially damaged when it was involved in an accident near Napa, California. The sole occupant on board sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed Ed Carlson Memorial Field - South Lewis County Airport (KTDO), Toledo, Washington, for a multi-leg cross-country flight destined for Napa County Airport (KAPC). During the approach to land at KAPC, about 8 miles north of the airport and 3,000 ft agl, the engine lost all power. The pilot cycled the throttle control to full, but the engine did not restart and the propeller continued to windmill. He then declared an emergency and initiated a forced landing onto an open field about 5 miles north of runway 19R. During the landing roll on unimproved terrain, the left wing struck a large rock and came to rest nose down. Subsequently, the left wing sustained substantial damage. Recovery of the airplane revealed that the airplane had about 13 gallons of fuel in its main tank and 7 gallons in its auxiliary tank. A postaccident examination of the airplane and engine did not reveal any preimpact mechanical anomalies. The fuel system was traced from each wing tank to the carburetor at the engine through the fuel selector, which rotated normally and was unobstructed. The fuel lines that had not been damaged from impact or removed to transport the airplane were secure. Mechanical continuity of the engine was established throughout the rotating group, valvetrain, and accessory section as the crankshaft was manually rotated at the propeller by hand. Thumb compression was achieved at all four cylinders and the valves displayed normal lift when the crankshaft was rotated. Examination of the cylinders’ combustion chamber interior components using a lighted borescope revealed normal piston face and valve signatures, and no indications of catastrophic engine failure. At 1754, the weather reported at KAPC, about 6 miles south of the accident site, included a temperature of 63°F and a dew point 52°F; the calculated relative humidity was about 67%. Review of the icing probability chart contained within FAA Special Airworthiness Information Bulletin CE-09-35 revealed that the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power." The pilot added that he did not use carburetor heat during the descent and approach into KAPC and that he should have used a prelanding checklist.

Aircraft

Registration
N201MM
Reported as
Mooney M-18C 55 (NO SERIES)
Category
Airplane
Serial number
357
Built
1955
Airframe hours
1,018.7
Engine
Continental C-85-12F, 85 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Karen Harms, Michael Harms, Oren Redsun
Registered owner
Karen Harms, Michael Harms, Oren Redsun
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 20, 2023 · 12 hours before
Departed
O37 · Willows, CA
Destination
Same as departure
Airport
APC · Napa County
Equipment
None

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
58
Injuries
Minor
Certificate
Private
Airplane ratings
Single-engine land
Medical
BasicMed, Waiver time limited special
Seat
Single
Restraint
Lap only
Flight hours
224 total · 10 in this make and model · 224 as pilot in command · 16 in the last 90 days · 11 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 18 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
63 °F, dew point 52 °F
Altimeter
29.84 inHg
Observed at
KAPC, 6 nm away
METAR
KAPC 260054Z 20018KT 10SM CLR 17/11 A2984 RMK AO2 SLP095 T01670111

Docket · 5

The files NTSB released with the investigation on June 4, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.8 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.