# NTSB ANC88FA111: Cessna 402B, N5718M, Mt. Torbet, AK, August 18, 1988

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: August 17, 1988, 20:03 local (Aug 18, 1988, 04:03 UTC)
- Place: Mt. Torbet, AK
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report December 3, 1989
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4961
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC88FA111
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4961/pdf
- Page: https://openairdocs.org/ntsb/ANC88FA111

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with terrain/water, descent
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - snow covered (contributing factor)
  - weather condition - whiteout (contributing factor)
  - vfr flight into imc - attempted, copilot/second pilot (cause)
  - procedures/directives - not followed, pilot in command (cause)
  - insufficient standards/requirements,airman, company/operator mgmt (contributing factor)

## Analysis

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.

## Aircraft

- Registration: [N5718M](https://openairdocs.org/deregistered/N5718M-2013-04-23), registration cancelled 2013-04-23, S/N 402B0354, built 1973 (OpenAirDocs)
- Reported make and model: CESSNA 402B
- Registry model: [Cessna 402B](https://openairdocs.org/model/cessna-402b) (registry code 207590P) (OpenAirDocs)
- Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 402B0354
- Airframe hours: 3051
- Engines: CONTINENTAL TSIO-520-E 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: Wilburs Inc., doing business as Wilburs Flight Operations
- Registered owner: Wilburs Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 16, 1988, 5 hours before
- Departed: SLQ, SLEETMUTE, AK
- Destination: MRI, ANCHORAGE, AK
- Airport: NONE

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 3,452 total, 1,248 in this make and model, 202 in the last 90 days, 156 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 120° at 50 knots
- Visibility: 1 statute miles

## 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 19880817034099A](https://openairdocs.org/incident/19880817034099A), Aug 17, 1988: Cessna 402B, Mt Torbert, AK, Substantial damage, 2 fatal. Flew into snow covered side of a mountain. Was operating VFR under an overcast that may have blended with snow area

## Other investigations on N5718M (3)

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.

- [NTSB ANC88IA013](https://openairdocs.org/ntsb/ANC88IA013), Oct 26, 1987: Cessna 402B (N5718M), Cordova, AK, incident, minor damage
- [NTSB ANC82DA047](https://openairdocs.org/ntsb/ANC82DA047), Jun 9, 1982: Cessna 402B (N5718M), Grayling, AK, substantial damage
- [NTSB ANC75AA060](https://openairdocs.org/ntsb/ANC75AA060), Feb 28, 1975: Cessna 402B (N5718M), Barrow, AK, substantial damage

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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