# NTSB WPR21LA293: Enstrom F-28A, N46MU, Mountain Home, ID, July 28, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: July 28, 2021, 11:30 local (17:30 UTC)
- Place: Mountain Home, ID
- Coordinates: 43.131389, -115.7303
- Nearby events: https://openairdocs.org/map.md?lat=43.1314&lon=-115.7303&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-hover: Fuel exhaustion](https://openairdocs.org/ntsb-events/192)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 103577
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA293
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103577/pdf
- Page: https://openairdocs.org/ntsb/WPR21LA293

## Probable cause

The pilot's improper fuel planning and improper in-flight decision-making, which resulted in a total loss of engine power due to fuel exhaustion and a subsequent hard landing on uneven terrain.

## 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: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=3300406), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md)
- [Planning/preparation: fuel planning](https://openairdocs.org/ntsb-findings/02061030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-findings/02061030/cases.md?model=3300406), [All aircraft, 719 cases](https://openairdocs.org/ntsb-findings/02061030/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=3300406), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=3300406), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-findings/03021017/cases.md?model=3300406), [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md)

## Sequence of events

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

- [Maneuvering-hover: Fuel exhaustion](https://openairdocs.org/ntsb-events/192) (defining event); cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-events/192/sequence.md?model=3300406), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md)
- [Maneuvering-hover: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Enstrom F-28A, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3300406), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Enstrom F-28A, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=3300406), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)

## Analysis

The pilot reported that, while the helicopter was in the hanger, he put 4 gallons of fuel into the left fuel tank. He then intended to hover taxi to the fuel island for fuel. He observed people and an aircraft near the fuel island, and he hover taxied to a dirt area. While about 12-15 ft above ground level, the engine had a complete loss of power. He further reported that he was too low to autorotate, landed hard on uneven terrain and collapsed the left skid. An inspection revealed that both fuel tanks were empty. The helicopter sustained substantial damage to the fuselage and main rotor blades. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

## Aircraft

- Registration: [N46MU](https://openairdocs.org/aircraft/N46MU), registered now, S/N 253 (OpenAirDocs)
- Reported make and model: ENSTROM F-28A
- Registry model: [Enstrom F-28A](https://openairdocs.org/model/enstrom-f-28a) (registry code 3300406) (OpenAirDocs)
- Registry engine: [Lycoming I0-360-B1E](https://openairdocs.org/engine/lycoming-i0-360-b1e) (registry code 41559, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 253
- Year built: 1974
- Airframe hours: 3907
- Engines: Lycoming HIO-360-C1A 205 hp reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Holmes, Robert Theodore
- Registered owner: Holmes, Robert Theodore
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 23, 2020, 5 hours before
- Departed: U76, Mountain Home, ID
- Destination: Same as departure
- Airport: U76, Mountain Home Municipal Airport
- Equipment: None

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review August 25, 2020; seat: left; restraint: 4-point; flight hours: 3,100 total, 5 in this make and model, 2,885 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 12 knots
- Visibility: 10 statute miles
- Temperature: 88 °F, dew point 46 °F
- Altimeter: 30.14 inHg
- Observed at: KMUO, 8 nm away
- METAR: KMUO 281758Z AUTO 32012KT 10SM FEW150 31/08 A3014 RMK AO2 SLP174 T03060077 10306 20231 50005 $

## 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 20210728012049A](https://openairdocs.org/incident/20210728012049A), Jul 28, 2021: Enstrom F-28A, Mountian Home, ID, Substantial damage. On July 28 pilot[privacy data omitted] determined the helicopter needed fuel. He was unsure about the fuel quantity so he put in 2-3 gallons of fuel. While…

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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