# NTSB CEN21LA419: Thatcher CX4, N306TA, Marshalltown, IA, September 9, 2021

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Class 4 · Limited · Final report
- Date: September 9, 2021, 12:45 local (17:45 UTC)
- Place: Marshalltown, IA
- Coordinates: 42.1226, -92.9455 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.1226&lon=-92.9455&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach: Fuel exhaustion](https://openairdocs.org/ntsb-events/192)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: Federal Aviation Administration; Des Moines FSDO
- NTSB case key (mKey): 103861
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA419
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103861/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103861
- Page: https://openairdocs.org/ntsb/CEN21LA419

## Probable cause

The pilot’s failure to properly determine the correct fuel quantity during preflight inspection that resulted in a loss of engine power during approach due to fuel exhaustion.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=056259Y), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Fuel system: fuel indication system](https://openairdocs.org/ntsb-findings/01022840): Aircraft › Aircraft systems · Related operating info; cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-findings/01022840/cases.md?model=056259Y), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/01022840/cases.md)
- [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Flight crew (probable cause); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=056259Y), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Prior to flight: Aircraft inspection event](https://openairdocs.org/ntsb-events/050); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/050/sequence.md?model=056259Y), [All aircraft, 229 cases](https://openairdocs.org/ntsb-events/050/sequence.md)
- [Approach: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=056259Y), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md)
- [Approach: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056259Y), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Approach: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=056259Y), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=056259Y), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Landing-flare/touchdown: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Finley Wilbur H THATCHER CX4, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=056259Y), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)

## Analysis

The pilot stated that he visually inspected the airplane fuel quantity before the flight and estimated there was 6 gallons of fuel. He said there was enough fuel for the planned flight with a fuel consumption rate of 3.5 gallons/hour. After he flew to an airport to perform a touch-and-go landing, in addition to local area flying, he began a return flight to the departure airport. He then realized that the airplane fuel quantity gauge indicated a fuel consumption that was greater than he had planned. About 3 miles from the departure/destination airport, the fuel gauge indicated near empty, and the engine ceased operation. He said he restarted the engine, which operated for about 5 seconds and then quit again. The pilot performed a forced landing on a corn field, during which the airplane nosed over. The airplane sustained substantial damage that included damage to the fuselage, empennage, and both wings. The pilot said the loss of engine power was due to his overestimation of fuel quantity during his preflight of the airplane and the inaccuracy of the fuel gauge. The pilot said there was no mechanical malfunction or failure of the airplane that would have precluded normal operations.

## Aircraft

- Registration: [N306TA](https://openairdocs.org/deregistered/N306TA-2022-04-02), registration cancelled 2022-04-02, S/N CX159, built 2008 (OpenAirDocs)
- Reported make and model: Thatcher CX4
- Registry model: [Finley Wilbur H THATCHER CX4](https://openairdocs.org/model/finley-wilbur-h-thatcher-cx4) (registry code 056259Y) (OpenAirDocs)
- Registry engine: [Revmaster 2100](https://openairdocs.org/engine/revmaster-2100) (registry code 52550, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: CX159
- Year built: 2008
- Airframe hours: 359
- Engines: Revmaster 2100D 65 hp reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Pilot
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, September 19, 2020
- Destination: Same as departure
- Airport: MIW, Marshalltown Municipal Airport

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 68; injuries: minor; private; airplane ratings: single-engine land; medical: sport pilot; seat: single; flight hours: 242 total, 80 in this make and model, 219 as pilot in command, 18 in the last 90 days, 3 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 72 °F, dew point 54 °F
- Altimeter: 30.07 inHg
- Observed at: MIW, 1.5 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20210909015499A](https://openairdocs.org/incident/20210909015499A), Sep 9, 2021: Finley Wilbur H THATCHER CX4, Marshalltown, IA, Destroyed. Aircraft ran out of fuel, landed in a corn field, aircraft flipped over.

## Docket (2 files)

The files NTSB released with the investigation on October 14, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103861. 2.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12754101&FileExtension=pdf&FileName=6120_1%20Master_Redacted-Rel.pdf
- Aircraft wreckage photo (item 2, PDF, 1 page, 417 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12754711&FileExtension=pdf&FileName=Photo-Rel.pdf

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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