ANC99LA066 · de Havilland DHC 2 MK III DHC 2 MK I
de Havilland DHC 2 MK III DHC 2 MK I · Accident: hard landing
From Lake Hood Airport (Z41) to an unrecorded destination
Event
- NTSB case
- ANC99LA066
- 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
- General aviation
- 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 2 MK III DHC 2 MK I
- Aircraft type
- de Havilland DHC-2
- 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
- N30CC
- Operator
- William A. Sego · private individual
- Onboard fatalities
- Unknown
- Route
- From Lake Hood Airport (Z41)To not recorded
- 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 91: General Aviation
- 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
- Landing · flare/touchdown
- 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
- Hard landing
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Stall
- 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(cfi) › Supervision, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot-in-command, a certificated flight instructor, was providing turbine transition instruction to the second pilot. The accident airplane had been modified by the installation of a Pratt & Whitney PT6 turbine engine. The instructor pilot stated that the propeller governor control was causing 'the engine to surge.' He added that just prior to touchdown on runway 31, while the second pilot was manipulating the controls, the engine again surged, and the airplane landed hard. In the pilot-in-command's written report, and during a later telephone conversation, he reported that during the previous landings, the second pilot failed to 'carry power so as not to land hard again.' The first pilot said that he then instructed the second pilot as to the differences of a turbine engine vs. a piston engine. He wrote: 'I watched very closely until we were over the runway, and once again, quick as a cat, we stalled and hit hard.' The airplane's fuselage sustained substantial damage.
Probable cause
The certificated flight instructor's inadequate supervision of the duel student. Factors associated with the accident were the student's inadvertent stall, and a surging turboshaft engine.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC99LA066
- Event ID
- 20001212X18679
- Case number
- ANC99LA066
- 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: 1fc99bb014383304a9fe23ea79be9cf42a4c366dd664020807ceb76cf0e37927; retrieved 2026-09-22T15:01:23.539Z.