# NTSB WPR21LA139: Beech B19, N1956W, Twin Falls, ID, March 18, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: March 18, 2021, 00:30 local (06:30 UTC)
- Place: Twin Falls, ID · Airport Environment
- Coordinates: 42.481806, -114.48775
- Nearby events: https://openairdocs.org/map.md?lat=42.4818&lon=-114.4878&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Defining event: [Initial climb: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390)
- Highest injury: No injuries
- Injuries: 3 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): 102789
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA139
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102789/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102789
- Page: https://openairdocs.org/ntsb/WPR21LA139

## Probable cause

The pilot’s failure to maintain airplane control during initial climb with a crosswind when the airspeed decreased, the airplane exceeded its critical angle of attack and aerodynamical stalled at too low an altitude for the pilot to recover before the airplane descended and landed hard.

## Findings

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

- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Beech B19, 2 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=1151215), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Beech B19, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1151215), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Beech B19, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=1151215), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Beech B19, 3 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=1151215), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md)

## Sequence of events

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

- [Initial climb: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Beech B19, 1 case](https://openairdocs.org/ntsb-events/390/sequence.md?model=1151215), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md)
- [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Beech B19, 2 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=1151215), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md)

## Analysis

The pilot reported that during the initial climb from runway 08 with a crosswind, the airplane attained an altitude of about 50 ft above ground level when it encountered low level wind shear. The airspeed decreased, and the airplane stalled. The pilot attempted to recover airspeed by lowering the nose, but there was not enough altitude or time. The airplane subsequently landed hard substantially damaging the right wing and aft fuselage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. About the time of the accident the reported wind was from 180o at 18 knots.

## Aircraft

- Registration: [N1956W](https://openairdocs.org/aircraft/N1956W), registered now, S/N MB-620 (OpenAirDocs)
- Reported make and model: BEECH B19 (NO SERIES)
- Registry model: [Beech B19](https://openairdocs.org/model/beech-b19) (registry code 1151215) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: MB-620
- Year built: 1973
- Airframe hours: 2366
- Engines: Lycoming O-320-E3D 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 16, 2020, 77.2 hours before
- Destination: BMC, Brigham City, UT
- Airport: TWF, Joslin Fld - Magic Valley Rgnl, runway 08, 8,703 × 150 ft, asphalt
- Equipment: Electronic flight bag or handheld device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 20; injuries: none; private; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; seat: left; flight hours: 79.7 total, 79.7 in this make and model

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 180° at 18 knots
- Visibility: 10 statute miles
- Temperature: 54 °F, dew point 25 °F
- Altimeter: 29.96 inHg
- Observed at: KTWF
- METAR: METAR KTWF 190553Z AUTO 18018KT 10SM FEW120 12/M04 A2996 RMK AO2 PK WND 18026/0544 SLP115 T01171039 10189 20100 58006=

## Docket (4 files)

The files NTSB released with the investigation on September 21, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102789. 9.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 8.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12660115&FileExtension=pdf&FileName=WPR21LA139%206120_Redacted-Rel.pdf
- Weather and performance information (item 2, PDF, 4 pages, 336 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12708473&FileExtension=pdf&FileName=weather%20-%20crosswind%20and%20perfromance%20information-Rel.pdf
- Summary of findings NTSB (item 3, PDF, 1 page, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12659601&FileExtension=pdf&FileName=Summary%20of%20Findings%20NTSB%20WPR21LA139_Redacted-Rel.pdf
- Photos-- courtesy of the FAA (item 4, PDF, 2 pages, 675 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12660013&FileExtension=pdf&FileName=Photos%20-%20courtesy%20of%20FAA-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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