# NTSB WPR20CA273: Schweizer SGS233, N7547, Warner Springs, CA, August 14, 2020

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Data collection · Final report
- Date: August 14, 2020, 13:30 local (20:30 UTC)
- Place: Warner Springs, CA
- Coordinates: 33.284442, -116.669723 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=33.2844&lon=-116.6697&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-descent: Loss of lift](https://openairdocs.org/ntsb-events/500)
- 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
- NTSB case key (mKey): 101816
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20CA273
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101816/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101816
- Page: https://openairdocs.org/ntsb/WPR20CA273

## Probable cause

The pilot's inability to maintain altitude due to a loss of thermal lift, which resulted in an off-airport landing.

## Findings

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

- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Schweizer SGS 2-33A, 6 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=8051606), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Temp/humidity/pressure: thermal lifting](https://openairdocs.org/ntsb-findings/03031040): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Schweizer SGS 2-33A, 3 cases](https://openairdocs.org/ntsb-findings/03031040/cases.md?model=8051606), [All aircraft, 53 cases](https://openairdocs.org/ntsb-findings/03031040/cases.md)

## Sequence of events

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

- [Enroute-descent: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Schweizer SGS 2-33A, 4 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=8051606), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Enroute-descent: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Schweizer SGS 2-33A, 5 cases](https://openairdocs.org/ntsb-events/500/sequence.md?model=8051606), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md)
- [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Schweizer SGS 2-33A, 8 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=8051606), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)

## Analysis

The glider pilot reported that, during the return flight to the airport, he encountered more downdrafts than expected and did not have enough altitude to reach the airport. He selected an area for the forced landing where during the landing roll on the rough terrain, both wings sustained substantial damage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the glider that would have precluded normal operation.

## Factual narrative

The glider pilot reported that, during the return flight to the airport, he encountered more downdrafts than expected and did not have enough altitude to reach the airport. He selected an area for the forced landing where during the landing roll on the rough terrain, both wings sustained substantial damage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the glider that would have precluded normal operation.

## Aircraft

- Registration: [N7547](https://openairdocs.org/aircraft/N7547), registered now, S/N 177, built 1970 (OpenAirDocs)
- Reported make and model: Schweizer SGS233 (A)
- Registry model: [Schweizer SGS 2-33A](https://openairdocs.org/model/schweizer-sgs-2-33a) (registry code 8051606) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 177
- Year built: 1970
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Departed: CL35, Warner Springs, CA
- Destination: CL35, Warner Springs, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 18; injuries: none; student; last flight review July 19, 2020; seat: front; restraint: none; flight hours: 33 total, 20 in this make and model, 19 as pilot in command, 8 in the last 90 days, 5 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 91 °F, dew point 70 °F
- Altimeter: 29.86 inHg
- Observed at: KRNM, 19 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 20200814013629A](https://openairdocs.org/incident/20200814013629A), Aug 14, 2020: Schweizer SGS 2-33A, Warner Springs, CA, Substantial damage. Glider pilot had normal take off and released the glider over hot spring at approximately 63OO feet MSL. After that pilot gained some more altitude and headed…

## Other investigations on N7547 (2)

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.

- [NTSB LAX83LA145](https://openairdocs.org/ntsb/LAX83LA145), Mar 7, 1983: Schweizer SGS2-33A (N7547), Fremont, CA, minor damage
- [NTSB OAK73DVD27](https://openairdocs.org/ntsb/OAK73DVD27), Mar 20, 1973: Schweizer SGS233 (N7547), Fremont, CA, substantial damage

## Docket (2 files)

The files NTSB released with the investigation on October 20, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101816. 19.1 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 18.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11346730&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf
- Photos (item 2, PDF, 3 pages, 208 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11346861&FileExtension=pdf&FileName=Photo%201-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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