# NTSB WPR15CA066: Ferdon Thorp T 18, N25VP, San Rafael, CA, December 20, 2014

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: December 20, 2014, 12:30 local (20:30 UTC)
- Place: San Rafael, CA
- Coordinates: 38.009998, -122.5 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.0100&lon=-122.5000&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report February 11, 2015
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- NTSB case key (mKey): 90516
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15CA066
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90516/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90516
- Page: https://openairdocs.org/ntsb/WPR15CA066

## Probable cause

The pilot's delayed decision to abort the takeoff. Contributing to the accident are an inadequate modification to the seat position, and the pilot's failure to check flight controls for freedom and correct movement.

## Findings

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

- [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=8951074), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md)
- [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=8951074), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md)
- [Maintenance: modification/alteration](https://openairdocs.org/ntsb-findings/02062030): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-findings/02062030/cases.md?model=8951074), [All aircraft, 69 cases](https://openairdocs.org/ntsb-findings/02062030/cases.md)

## Sequence of events

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

- [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=8951074), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Takeoff-rejected takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=8951074), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Takeoff-rejected takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Ferdon THORP T-18, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=8951074), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md)

## Analysis

The pilot reported that prior to the flight in the experimental airplane, he unbolted and rebolted the pilot's seat from its middle position to the forward position. He did not check to see if the flight control stick movement would be restricted in this new configuration. During the takeoff roll, the airplane would not rotate when he moved the flight control stick aft. Not realizing the seat prevented the flight control stick movement to the full aft position, the pilot adjusted the elevator trim and the airplane subsequently lifted off, however, it would not climb. The pilot then aborted the takeoff; however, the airplane did not have sufficient distance to stop. It departed the runway surface and traversed through a field, impacted trees, and came to rest inverted. The airplane sustained substantial damage to the wings, rudder, and vertical stabilator. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.

## Factual narrative

The pilot reported that prior to the flight in the experimental airplane, he unbolted and rebolted the pilot's seat from its middle position to the forward position. He did not check to see if the flight control stick movement would be restricted in this new configuration. During the takeoff roll, the airplane would not rotate when he moved the flight control stick aft. Not realizing the seat prevented the flight control stick movement to the full aft position, the pilot adjusted the elevator trim and the airplane subsequently lifted off, however, it would not climb. The pilot then aborted the takeoff; however, the airplane did not have sufficient distance to stop. It departed the runway surface and traversed through a field, impacted trees, and came to rest inverted. The airplane sustained substantial damage to the wings, rudder, and vertical stabilator. The pilot reported no preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.

## Aircraft

- Registration: [N25VP](https://openairdocs.org/deregistered/N25VP-2018-05-30), registration cancelled 2018-05-30, S/N 07, built 1975 (OpenAirDocs)
- Reported make and model: FERDON THORP T 18 (UNDESIGNAT)
- Registry model: [Ferdon THORP T-18](https://openairdocs.org/model/ferdon-thorp-t-18) (registry code 8951074) (OpenAirDocs)
- Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs)
- Category: Airplane
- Serial number: 07
- Year built: 1975
- Airframe hours: 1570
- Engines: Lycoming O-290-D2 135 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Bashforty Glenn
- Registered owner: Bashforty Glenn
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, September 9, 2014
- Departed: CA35, SAN RAFAEL, CA
- Destination: DVO, NOVATO, CA
- Airport: CA35, San Rafael, runway 04, 2,140 × 30 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review January 6, 2014; seat: left; flight hours: 1,530 total, 9 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 7 statute miles
- Lowest ceiling: 3,500 ft broken
- Temperature: 64 °F
- Altimeter: 29.92 inHg
- Observed at: KDVO, 6 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 20141220023769A](https://openairdocs.org/incident/20141220023769A), Dec 20, 2014: Ferdon THORP T-18, San Rafael, CA, Substantial damage. [privacy data omitted] Purchased aircraft N25VP a month prior to the event. The aircraft had received a conditional inspection a month prior and was found to…

## Docket (5 files)

The files NTSB released with the investigation on February 2, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90516. 2.4 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 891 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40422020&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Record of Conversation - Pilot (item 2, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40422021&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Pilot-Master.PDF
- Record of Email - FAA Inspector (item 3, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40422022&FileExtension=.PDF&FileName=Record%20of%20Email%20-%20FAA%20Inspector-Master.PDF
- Photo 1 - Main Wreckage (Photo Courtesy of FAA) (item 4, .PDF, 642 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40422023&FileExtension=.PDF&FileName=Photo%201%20-%20Main%20Wreckage%20(Photo%20Courtesy%20of%20FAA)-Master.PDF
- Photo 2 - Main Wreckage (Photo Courtesy of FAA) (item 5, .PDF, 720 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40422024&FileExtension=.PDF&FileName=Photo%202%20-%20Main%20Wreckage%20(Photo%20Courtesy%20of%20FAA)-Master.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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