# NTSB WPR09CA461: Cessna 172S, N21591, San Carlos, CA, September 21, 2009

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: September 21, 2009, 10:30 local (17:30 UTC)
- Place: San Carlos, CA
- Coordinates: 37.48941, -122.2602 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.4894&lon=-122.2602&mi=10
- Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping)
- Defining event: [Taxi-to runway: Ground collision](https://openairdocs.org/ntsb-events/200)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 15, 2009
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 74784
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA461
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74784/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74784
- Page: https://openairdocs.org/ntsb/WPR09CA461

## Probable cause

The student pilot's failure to maintain clearance with a fence post during taxi.

## Findings

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

- [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Student/instructed pilot (probable cause); cases with it: [Cessna 172S, 11 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=2072439), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md)
- [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Response/compensation (probable cause); cases with it: [Cessna 172S, 7 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=2072439), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md)

## Sequence of events

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

- [Taxi-to runway: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event); cases with it: [Cessna 172S, 23 cases](https://openairdocs.org/ntsb-events/200/sequence.md?model=2072439), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md)

## Analysis

The student pilot's attention was momentarily diverted as he was taxiing around another airplane to the runup area. The pilot subsequently heard the right wing impact a fence post, which resulted in substantial damage to the wing's leading edge.

## Factual narrative

The student pilot reported that his attention was momentarily diverted as he was taxiing around another airplane to the runup area. The pilot subsequently heard the right wing impact a fence post, which resulted in substantial damage to the wing's leading edge.

## Aircraft

- Registration: [N21591](https://openairdocs.org/aircraft/N21591), registered now, S/N 172S9658, built 2004 (OpenAirDocs)
- Reported make and model: CESSNA 172S
- Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (registry code 2072439) (OpenAirDocs)
- Registry engine: [Lycoming IO-360-L2A](https://openairdocs.org/engine/lycoming-io-360-l2a) (registry code 41597, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 172S9658
- Airframe hours: 2450
- Engines: Lycoming IO-360-L2A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Scott A.W. Ellison
- Registered owner: Golden Gate Helicopters Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 17, 2009
- Departed: SQL, San Carlos, CA
- Destination: SQL, San Carlos, CA
- Flight plan: Unknown
- Airport: SQL, San Carlos, runway 12, 2,600 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Student pilot; age 37; injuries: none; student; medical: class 3, without waivers/limitations; seat: left; flight hours: 108 total, 108 in this make and model, 15 as pilot in command, 20 in the last 90 days, 12 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 4 knots
- Visibility: 5 statute miles
- Lowest ceiling: none
- Temperature: 64 °F, dew point 59 °F
- Altimeter: 30.01 inHg
- Observed at: SQL

## Docket (1 files)

The files NTSB released with the investigation on September 28, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74784. 668 KB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 668 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40319264&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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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