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ANC93LA046 · Piper PA-22

20 Mar 1993 · DRIFT RIVER, AK, United States

Piper PA-22 · Accident: in flight collision with terrain/water en route

From Alaska Airpark (AK01) to King Salmon Airport (AKN)

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Event

NTSB case
ANC93LA046
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
Instrument Meteorological Cond

Piper PA-22

Aircraft type
Piper PA-22
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
N72999
Operator
Johnson, Ronald B. · private individual
Onboard fatalities
Unknown
Route
From Alaska Airpark (AK01), Palmer, AKTo King Salmon Airport (AKN), KING SALMON, 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 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
En route · climb to cruise
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
In flight collision with terrain/water
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
Visual flight rules (VFR) flight into instrument meteorological conditions (IMC)
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 › VFR flight into imc, inadvertent

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

NTSB narrative

DURING THE PILOT'S FIRST ATTEMPT TO FLY THROUGH LAKE CLARK PASS, HE MISTAKENLY TURNED UP THE WRONG VALLEY. WHEN THE ALREADY POOR FLIGHT VISIBILITY CONTINUED TO DETERIORATE, HE BEGAN A 180 DEGREE TURN TO GET OUT OF THE VALLEY, DURING WHICH HE ENTERED WHITEOUT CONDITIONS. WHEN HE SAW MOUNTAINS ON BOTH SIDES, HE KNEW THAT HE HAD MISSED THE TURN OUT OF THE VALLEY. WITH NO DEPTH PERCEPTION ON WHICH TO ESTIMATE HIS ALTITUDE ABOVE THE GROUND, HE APPLIED FULL ENGINE POWER AND MAINTAINED THE BEST CLIMB ATTITUDE. VERY SOON AFTERWARD THE AIRPLANE COLLIDED WITH, AND NOSED OVER ON, A GLACIER. DURING THE PREFLIGHT WEATHER BRIEFING THE PILOT WAS TOLD THAT LAKE CLARK PASS WAS FORECAST TO BE MARGINAL VFR TO IFR.

Probable cause

THE PILOTS INADVERTENT VFR FLIGHT INTO IMC CONDITIONS. FACTORS WERE THE RISING TERRAIN AND THE WHITEOUT CONDITIONS.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record ANC93LA046
Event ID
20001211X11903
Case number
ANC93LA046
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: ad909351684f8367e19e7d86b2be72605f07eaee1bce87be176236cf34a9b1ac; retrieved 2026-09-23T02:14:47.143Z.