# NTSB ANC23LA081: Piper/Gerbi Charles R PA 18-150, N4900C, Juneau, AK, September 11, 2023

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 4 · Limited · Final report
- Date: September 10, 2023, 17:30 local (Sep 11, 2023, 01:30 UTC)
- Place: Juneau, AK
- Coordinates: 58.59667, -135.5156
- Nearby events: https://openairdocs.org/map.md?lat=58.5967&lon=-135.5156&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Alaska Regional Office
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 193100
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC23LA081
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193100/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193100
- Page: https://openairdocs.org/ntsb/ANC23LA081

## Probable cause

The student pilot’s failure to maintain altitude after the airplane encountered a downdraft while maneuvering over an area of hilly terrain.

## Findings

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

- [Wind: downdraft](https://openairdocs.org/ntsb-findings/03034035): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Piper/Gerbi Charles R PA 18-150, 1 case](https://openairdocs.org/ntsb-findings/03034035/cases.md?model=7101851), [All aircraft, 178 cases](https://openairdocs.org/ntsb-findings/03034035/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: [Piper/Gerbi Charles R PA 18-150, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=7101851), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Piper/Gerbi Charles R PA 18-150, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101851), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)

## Sequence of events

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

- [Maneuvering: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) (defining event); cases with it: [Piper/Gerbi Charles R PA 18-150, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101851), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The student pilot stated he departed from his remote cabin and recalled experiencing significant downdrafts while maneuvering in an area of hilly terrain. The next thing he remembered is trying to turn off the key after the accident, and then waking up in a hospital. The fuselage and both wings sustained substantial damage. During a postaccident interview with a Federal Aviation Administration inspector, the pilot stated there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot did not submit the National Transportation Safety Board Pilot/Operator Aircraft Accident/Incident Report Form 6120.1.

## Aircraft

- Registration: [N4900C](https://openairdocs.org/aircraft/N4900C), registered now, S/N AI-18062, built 2013 (OpenAirDocs)
- Reported make and model: PIPER/GERBI CHARLES R PA 18-150
- Registry model: [Piper/Gerbi Charles R PA 18-150](https://openairdocs.org/model/piper-gerbi-charles-r-pa-18-150) (registry code 7101851) (OpenAirDocs)
- Registry engine: [Lycoming O-320-A2B](https://openairdocs.org/engine/lycoming-o-320-a2b) (registry code 42101, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: AI-18062
- Year built: 2013
- Engines: LYCOMING O-320-A2B 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Equipment: Unknown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: serious; student; medical: basicmed, unknown; seat: front

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 54 °F
- Altimeter: 29.69 inHg
- Observed at: AGS, 13 nm away
- METAR: PAGS 110056Z AUTO 32007KT 10SM CLR 16/12 A2969 RMK AO2 SLP055 T01560122

## 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 20230910014769A](https://openairdocs.org/incident/20230910014769A), Sep 10, 2023: Piper/Gerbi Charles R PA 18-150, Excursion Inlet, AK, Substantial damage. The airman stated he departed his cabin near gustavus and was enroute to endicott river wilderness area. He crashed into the mountainside approximately 10…

## Other investigations on N4900C (1)

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 ANC21LA008](https://openairdocs.org/ntsb/ANC21LA008), Dec 3, 2020: Piper PA18 (N4900C), Juneau, AK, substantial damage. Probable cause: The solo student pilot’s failure to maintain directional control during taxi in strong crosswind conditions, which resulted in a loss of control and subsequent impact with a ditch.

## Docket (2 files)

The files NTSB released with the investigation on August 30, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193100. 488 KB in all.

- FAA inspector's statement (item 1, PDF, 1 page, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16828867&FileExtension=pdf&FileName=FAA%20Inspector%20Statement-Rel.pdf
- Photos (item 2, PDF, 2 pages, 424 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17277026&FileExtension=pdf&FileName=Photos-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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