WPR22LA337

NTSB accident investigation · Cessna 180 · Seeley Lake, MT · September 3, 2022

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
September 3, 2022, 15:00 local (21:00 UTC)
Place
Seeley Lake, MT · Wooded area
Injuries
2 serious
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N3135DCessna 180
Defining event
Approach-VFR pattern crosswind: Fuel starvation
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20220903015349A
Case key
105889

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 loss of engine power due to fuel starvation as a result of unporting of the fuel.

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.

Fuel systemAircraft › Aircraft systems · Incorrect use/operationCessna 180: 1 caseAll aircraft: 181 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelCessna 180: 12 casesAll aircraft: 1,695 casesProbable cause
Action: incorrect action performancePersonnel issues › Action/decision · PilotCessna 180: 4 casesAll aircraft: 1,386 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.

Fuel starvationApproach-VFR pattern crosswindCessna 180: 3 casesAll aircraft: 733 casesDefining event

Analysis

The accident pilot reported that he had topped the airplane off with fuel before departure. Following an uneventful flight, the pilot began a descent to the airport traffic pattern and enrichened the mixture and applied carburetor heat. While on the downwind for the runway, he noted that he had about 10.5 to 11 gallons of fuel remaining. The pilot conducted a low approach by descending over the runway using an intermediate power setting to inspect the runway for wildlife. As the pilot initiated a climb and turned onto the left crosswind leg, the engine lost all power about 300 ft above ground level, and he initiated a forced landing to a nearby clearing. Subsequently, the airplane impacted trees and came to rest in a nose-low attitude. Examination of the recovered airframe and engine revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation. The reported fuel level would have placed the fuel levels in both fuel tanks below 1/4 tank, which would prohibit takeoff according to the airplane owner’s manual. It’s likely that following the low pass over the runway, with the application of power and a climbing turn, the fuel was unported and interrupted the fuel delivery to the engine, which resulted in a loss of engine power.

Factual narrative

On September 3, 2022, about 1500 mountain daylight time, a Cessna 180, N3135D was substantially damaged when it was involved in an accident near Seeley Lake, Montana. The pilot and passenger were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he topped the airplane off with fuel before he departed from the Vance Brand Airport, Longmont, Colorado, and flew direct to Seeley Lake Airport (S23), Seeley Lake, Montana, at a cruise altitude between 10,500 and 12,500 ft mean sea level (msl). The pilot stated that during cruise flight, he leaned the mixture aggressively to a fuel burn between 9.5 and 10 gallons an hour. Following the uneventful flight, the pilot began a descent to the airport traffic pattern, enrichened the mixture, and applied carburetor heat. While on the downwind for runway 16, he noted that he had about 10.5 to 11 gallons of fuel remaining. The pilot conducted a low approach by descending over runway 16 using an intermediate power setting to inspect the runway for wildlife. As the pilot initiated a climb and turned onto the left crosswind leg, the engine lost all power about 300 ft above ground level; he initiated a forced landing to a nearby clearing. Subsequently, the airplane impacted trees and came to rest in a nose-low attitude. Postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that both wings and fuselage were substantially damaged. Review of photos provided by the FAA showed that the bottom of the fuselage was cut open by an unknown source. The left and right fuel lines from the wing tanks also appeared to be separated consistent with impact damage. The wreckage was recovered to a secure location for further examination. Wreckage recovery personnel reported that no fuel was recovered from either fuel tank. Examination of the recovered airframe and engine revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation. The position of the fuel selector valve was in the left fuel tank position, and the handle was separated from the valve. Both fuel tanks exhibited crush damage. The leading edge and portion of the left fuel tank was torn open, and the right fuel tank appeared to be intact. The left and right fuel tank float gauges were intact and were placarded “NO TAKEOFF” for ¼ tank or less. The airplane was equipped with two 30-gallon fuel tanks of which 27.5 gallons were useable. The airplane owner’s manual states, “a red arc on the face of each indicator, warns the pilot that the respective tank is less than one-quarter full. Do not take off if the pointer is in the red arc.”

Aircraft

Registration
N3135D
Reported as
Cessna 180
Category
Airplane
Serial number
31933
Built
1955
Airframe hours
3,840
Engine
Continental O-470-50, 270 hp, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Skycavu Inc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 15, 2022 · 15 hours before
Departed
LMO · Longmont, CO
Destination
Same as departure
Airport
23S · Seeley Lake, runway 16, 4,575 × 75 ft, grass/turf
Equipment
Onboard weather, Handheld GPS, Electronic flight bag or handheld device, ADS-B, 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
Serious
Certificates
Airline transport, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Seat
Left
Flight hours
1,600 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
300° at 3 knots
Visibility
8 statute miles
Lowest ceiling
None
Temperature
32 °F, dew point 32 °F
Altimeter
29.96 inHg
Observed at
KMSO, 30 nm away
METAR
METAR KMSO 032053Z 30003KT 8SM CLR 29/06 A2996 RMK AO2 SLP122 T02940056 58028=

Docket · 9

The files NTSB released with the investigation on September 5, 2024, on NTSB’s docket system: statements, records, photos and specialists’ reports. 9.4 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.