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Wilburs Cessna 402B accident

17 Aug 1988 · MT. TORBET, AK, United States

Cessna 402B · Accident: in flight collision with terrain/water en route

From Sleetmute Airport (SLQ) to Merrill Field (MRI)

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Event

NTSB case
ANC88FA111
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
2 · 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
Instrument Meteorological Cond

Cessna 402B

Aircraft type
Cessna 402
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
N5718M
Operator
Wilburs
Onboard fatalities
Unknown
Route
From Sleetmute Airport (SLQ), SLEETMUTE, AKTo Merrill Field (MRI), Anchorage, 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
En route · descent
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

  • Copilot/second pilot › VFR flight into imc, attempted
  • Pilot in command › Procedures/directives, not followed

Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.

NTSB narrative

THE ON-DEMAND-CHARTER FLIGHT WAS TO ORIGINALLY PICKUP PASSENGERS AND CARGO BUT A LANDING GEAR PROBLEM FORCED ANOTHER AIRPLANE WITH A MECHANIC TO BE DISPATCHED. THE OTHER AIRPLANE RETURNED WITH THE PASSENGERS AND THE ACCIDENT AIRPLANE WAS REPAIRED BY THE MECHANIC AND DEPARTED AT A LATER TIME WITH THE CARGO ON BOARD. THE AIRPLANE WAS NOT ON A FLIGHT PLAN. INSTRUMENT METEOROLOGICAL CONDITIONS PREVAILED FROM 7000 FEET MSL TO 12,500 FEET MSL AS REPORTED BY THE OTHER COMPANY AIRPLANE. THE AIRCRAFT WAS FOUND ON THE SIDE OF MT. TORBERT AT THE 10,570 FOOT LEVEL. THE PILOT-IN-COMMAND WAS FOUND IN THE RIGHT PILOT SEAT WITH A NON-AVIATION RELATED BOOK IN HIS LAP. THE MECHANIC WAS FOUND IN THE LEFT PILOT SEAT WITH A WORLD AERONAUTICAL CHART, CD-11 OPEN ON HIS LAP. THE MECHANIC HELD A COMMERCIAL PILOTS CERTIFICATE BUT NO INSTRUMENT RATING. THE INVESTIGATION REVEALED WEAKNESSES IN COMPANY OPERATIONS.

Verbatim NTSB analysis from the NTSB dataset

Sources

NTSB record ANC88FA111
Event ID
20001213X26405
Case number
ANC88FA111
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: local date, investigation status. Values present in the bulk record are kept.
  • The date is the local date; the NTSB stores the UTC date 1988-08-18.
  • API snapshot SHA-256: c70c356fcc9bc3e814d2838e5b47ebbbb295dd9dd2e4a3366b9d68d644ae5af6; retrieved 2026-09-18T14:10:47.347Z.