# NTSB WPR23LA322: Grumman American Avn. AA-5B, N4537Y, Lone Pine, CA, August 19, 2023

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 4 · Limited · Final report
- Date: August 18, 2023, 19:10 local (Aug 19, 2023, 02:10 UTC)
- Place: Lone Pine, CA
- Coordinates: 36.226698, -118.16611
- Nearby events: https://openairdocs.org/map.md?lat=36.2267&lon=-118.1661&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: Serious injuries
- Injuries: 1 serious, 1 minor
- 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): 192924
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR23LA322
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192924/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192924
- Page: https://openairdocs.org/ntsb/WPR23LA322

## Probable cause

The pilot's inability to maintain altitude after encountering a downdraft, which resulted in collision with terrain.

## Findings

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

- [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Grumman American Avn. AA-5B, 2 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=3960105), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md)
- [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Grumman American Avn. AA-5B, 1 case](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=3960105), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/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: [Grumman American Avn. AA-5B, 2 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=3960105), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Effect on operation; cases with it: [Grumman American Avn. AA-5B, 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=3960105), [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 · Ability to respond/compensate (probable cause); cases with it: [Grumman American Avn. AA-5B, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=3960105), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/cases.md)
- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Contributed to outcome (probable cause); cases with it: [Grumman American Avn. AA-5B, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=3960105), [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: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Grumman American Avn. AA-5B, 2 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=3960105), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md)
- [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Grumman American Avn. AA-5B, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=3960105), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md)

## Analysis

The pilot reported that, while conducting a low pass over an off-airport landing strip at an altitude of 100 ft above the ground, the airplane encountered a downdraft. The pilot felt the airplane was unable to climb out of the valley without stalling, so he maintained airspeed, but the airplane descended and impacted the ground. The airplane subsequently rebounded and came to a rest in an upright position, which resulted in substantial damage to both wings, fuselage, and empennage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N4537Y](https://openairdocs.org/deregistered/N4537Y-2024-12-03), registration cancelled 2024-12-03, S/N AA5B1292, built 1979 (OpenAirDocs)
- Reported make and model: GRUMMAN AMERICAN AVN. CORP. AA-5B
- Registry model: [Grumman American Avn. AA-5B](https://openairdocs.org/model/grumman-american-avn-aa-5b) (registry code 3960105) (OpenAirDocs)
- Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: AA5B1292
- Year built: 1979
- Airframe hours: 2209.8
- Engines: Lycoming A4K 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 11, 2023, 25 hours before
- Departed: KSMO, Santa Monica, CA
- Destination: KSMO, Santa Monica, CA
- Equipment: Handheld GPS, Onboard weather, Satellite tracking device, Stall warning system, ADS-B, Auto-pilot, Electronic flight bag or handheld device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 61; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review August 10, 2023; seat: left; restraint: 3-point; flight hours: 1,097 total, 16 in this make and model, 1,023 as pilot in command, 70 in the last 90 days, 32 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 97 °F, dew point 36 °F
- Altimeter: 29.92 inHg
- Observed at: KNID, 40 nm away
- METAR: KNID 181856Z AUTO 14005KT 10SM CLR 36/02 A2992 RMK AO2 SLP102 T03560017 $

## 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 20230818014389A](https://openairdocs.org/incident/20230818014389A), Aug 18, 2023: Grumman American Avn. Corp. AA-5B, Kernville, CA, Substantial damage. The pilot approached the mountainous air strip for the stated purpose of inspecting the condition of the landing surface. This information was for use by…

## Docket (2 files)

The files NTSB released with the investigation on November 30, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192924. 4.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16268024&FileExtension=pdf&FileName=WPR23LA322%206120%20flat_Redacted-Rel.pdf
- Photos (item 2, PDF, 3 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16282792&FileExtension=pdf&FileName=WPR23LA322%20Docket%20photo-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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