# NTSB WPR26LA188: Mcdonnell Douglas Helicopter 500, N952SF, Twin Falls, ID, May 14, 2026

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Class 4 · Limited · Final report
- Date: May 14, 2026, 14:30 local (20:30 UTC)
- Place: Twin Falls, ID
- Coordinates: 42.481809, -114.48773
- Nearby events: https://openairdocs.org/map.md?lat=42.4818&lon=-114.4877&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-hover: Dynamic rollover](https://openairdocs.org/ntsb-events/231)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report July 30, 2026
- 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): 202999
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR26LA188
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/202999/pdf
- Page: https://openairdocs.org/ntsb/WPR26LA188

## Probable cause

The pilot’s failure to maintain control while hovering in gusty wind conditions, resulting in the helicopter rolling onto its side.

## Findings

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

- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 6 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=3027369), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Performance/control parameters: lateral/bank control](https://openairdocs.org/ntsb-findings/01062023): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-findings/01062023/cases.md?model=3027369), [All aircraft, 390 cases](https://openairdocs.org/ntsb-findings/01062023/cases.md)
- [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=3027369), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md)

## Sequence of events

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

- [Maneuvering-hover: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=3027369), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=3027369), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Maneuvering-hover: Dynamic rollover](https://openairdocs.org/ntsb-events/231) (defining event); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-events/231/sequence.md?model=3027369), [All aircraft, 161 cases](https://openairdocs.org/ntsb-events/231/sequence.md)

## Analysis

The pilot stated he was maneuvering the helicopter around and near the airport property. While practicing hovering, he was evaluating the left lateral cyclic trim control. The helicopter encountered wind and rolled, coming to rest on its left side. During the accident sequence, the main rotor blades severed the tail boom from the airframe. The pilot stated there were no pre impact mechanical malfunctions or failures with the helicopter that would have precluded normal operation. At the time of the accident, the wind was from 320° at 11 knots, gusting to 17 knots.

## Aircraft

- Registration: [N952SF](https://openairdocs.org/aircraft/N952SF), registered now, S/N 0366E, built 1989 (OpenAirDocs)
- Reported make and model: MCDONNELL DOUGLAS HELICOPTER 500
- Registry model: [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e) (registry code 3027369) (OpenAirDocs)
- Registry engine: [Rolls-Royce 250-C20B](https://openairdocs.org/engine/rolls-royce-250-c20b) (registry code 54385, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 0366E
- Year built: 1989
- Engines: Allison 250C20B 420 hp turbo shaft
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Interparts General Business Inc
- Registered owner: Interparts General Business Inc
- Airworthiness certificate: Standard, Normal
- Departed: TWF, Twin Falls, ID
- Destination: Same as departure
- Airport: TWF, Joslin Fld/Magic Valley Rgnl
- Equipment: Satellite tracking device, ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 75; injuries: minor; private; airplane ratings: multi-engine land, single-engine land, single-engine sea; medical: basicmed, without waivers/limitations; last flight review June 15, 2024; seat: left; restraint: 4-point; flight hours: 9,700 total, 1,200 in this make and model, 4 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 11 knots, gusting 17
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 27 °F
- Altimeter: 30.06 inHg
- Observed at: KTWF, 1 nm away
- METAR: METAR KTWF 142053Z 32011G17KT 10SM CLR 19/M03 A3006 RMK AO2 SLP146 T01941028 58022=

## 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 20260514007189A](https://openairdocs.org/incident/20260514007189A), May 14, 2026: Mcdonnell Douglas Helicopter 369E, Twin Falls, ID, Destroyed. Pilot was hovering in the grass area and wanted to set down the aircraft before departure. Pilot stated he did not get the collective down properly to prevent…

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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