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Ketchum Air Service de Havilland DHC-3T accident

20 Aug 1999 · PORT ALSWORTH, AK, United States

de Havilland DHC-3T · Accident: overrun during takeoff

From an unrecorded airport to TUTNA LAKE, AK

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Event

NTSB case
ANC99LA122
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
Charter & commuter
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

de Havilland DHC-3T

Aircraft type
de Havilland DHC-3
Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N888KA
Onboard fatalities
Unknown
Route
From not recordedTo TUTNA LAKE, AK
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 135: Air Taxi & Commuter
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Takeoff · roll/run
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Overrun
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Pilot in command › Raising of flaps, inadvertent

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot told the NTSB investigator-in-charge he was attempting to takeoff from a remote lake. At the beginning of the takeoff water run, the hydraulically actuated flaps were retracted from the fully extended (takeoff) to 1/2 position. He said the airplane came up 'on step' normally, and he then attempted to pump the flaps to the fully extended position. The airplane did not become airborne, and he realized the flap selector handle was in the 'up,' not 'down,' position. The airplane struck the four feet high bank at the end of the lake, separating the floats. The pilot initially indicated he forgot to switch the flap selector handle to 'down.' He later stated he thought he had positioned it correctly, but his shirt sleeve may have snagged the handle and repositioned it.

Probable cause

The pilot's inadvertent retraction of the trailing edge flaps during the takeoff run.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ANC99LA122
Event ID
20001212X19409
Case number
ANC99LA122
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: b5701f90f31731fb960376937669d8c5f42624854c21ca0484311c8e5a687685; retrieved 2026-09-18T16:54:08.998Z.