# NTSB WPR20CA218: Rans S6, N644RS, Richland, WA, July 12, 2020

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Data collection · Final report
- Date: July 12, 2020, 11:40 local (18:40 UTC)
- Place: Richland, WA
- Coordinates: 46.410278, -119.585556 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.4103&lon=-119.5856&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Western Pacific Region
- Parties: FAA
- NTSB case key (mKey): 101586
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20CA218
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101586/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101586
- Page: https://openairdocs.org/ntsb/WPR20CA218

## Probable cause

The pilot's inability to arrest a descent rate or maintain altitude after encountering a downdraft while maneuvering at low altitude near mountainous terrain that resulted in a hard landing.

## Findings

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

- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=05637PY), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=05637PY), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Performance/control parameters: descent rate](https://openairdocs.org/ntsb-findings/01062037): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-findings/01062037/cases.md?model=05637PY), [All aircraft, 242 cases](https://openairdocs.org/ntsb-findings/01062037/cases.md)
- [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=05637PY), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md)
- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=05637PY), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md)

## Sequence of events

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

- [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=05637PY), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md)
- [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [David D Lake RANS S6 ES COYOTE II, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05637PY), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that, while maneuvering at low altitude on the leeward side of a ridge to follow elk, he encountered a downdraft and the airplane slightly pitched up and the airspeed decreased. The pilot lowered the nose attitude, applied full engine power, and turned away from the hill, however the airplane's descent rate continued to increase. Near the ground, the pilot tried to flare in ground effect but the descent rate did not slow as expected and the airplane landed hard, bending the left main landing gear under the airplane and substantially damaging the left wing when it struck the ground. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

## Factual narrative

The pilot reported that, while maneuvering at low altitude on the leeward side of a ridge to follow elk, he encountered a downdraft and the airplane slightly pitched up and the airspeed decreased. The pilot lowered the nose attitude, applied full engine power, and turned away from the hill, however the airplane's descent rate continued to increase. Near the ground, the pilot tried to flare in ground effect but the descent rate did not slow as expected and the airplane landed hard, bending the left main landing gear under the airplane and substantially damaging the left wing when it struck the ground. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N644RS](https://openairdocs.org/deregistered/N644RS-2021-09-04), registration cancelled 2021-09-04, S/N 12021475, built 2018 (OpenAirDocs)
- Reported make and model: RANS S6 (ES)
- Registry model: [David D Lake RANS S6 ES COYOTE II](https://openairdocs.org/model/david-d-lake-rans-s6-es-coyote-ii) (registry code 05637PY) (OpenAirDocs)
- Registry engine: [Suzuki G13BB](https://openairdocs.org/engine/suzuki-g13bb) (registry code 59305, 4 cycle) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 12021475
- Year built: 2018
- Airframe hours: 129
- Engines: Suzuki G13BB 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, April 4, 2020, 53 hours before
- Departed: YKM, Yakima, WA
- Destination: YKM, Yakima, WA
- Equipment: Onboard weather, Handheld GPS, Satellite tracking device, Electronic flight bag or handheld device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; injuries: none; private, flight instructor; airplane ratings: single-engine land; medical: class 2, waiver time limited special; last flight review May 4, 2019; seat: left; restraint: 3-point; flight hours: 1,950 total, 129 in this make and model, 1,872 as pilot in command, 84 in the last 90 days, 34 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 77 °F, dew point 50 °F
- Altimeter: 30.04 inHg
- Observed at: KRLD, 13 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 20200712004759A](https://openairdocs.org/incident/20200712004759A), Jul 12, 2020: David D Lake RANS S6 ES COYOTE II, Benton City, WA, Substantial damage. Pilot reported he was flying at 2800 ft MSL and observed elk on the rattlesnake moutain. He turned right toward mountain for pictures. As he approached…

## Docket (2 files)

The files NTSB released with the investigation on October 9, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101586. 1.2 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 730 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9998375&FileExtension=pdf&FileName=6120%20218_Redacted-Rel.pdf
- Accident photo (item 2, PDF, 1 page, 516 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10000430&FileExtension=pdf&FileName=Accident%20Photo%20218-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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