# NTSB ANC90LA026: Cessna 207A, N9720M, Nondalton, AK, January 12, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 12, 1990, 11:15 local (15:15 UTC)
- Place: Nondalton, AK
- Coordinates: 59.959053, -154.870788 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=59.9591&lon=-154.8708&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 6 uninjured
- Status: Completed, report September 30, 1991
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 5333
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC90LA026
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5333/pdf
- Page: https://openairdocs.org/ntsb/ANC90LA026

## Probable cause

IMPROPER PLANNING/DECISION BY THE PILOT.  FACTORS RELATED TO THE ACCIDENT WERE:  INADEQUATE POSITIONING OF THE TEMPORARY RUNWAY MARKERS, SNOW COVERED RUNWAY/TERRAIN CONDITIONS, PARTIAL WHITEOUT CONDITION, AND THE SNOW BERMS AT THE EDGES OF THE RUNWAY.

## Sequence of events

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

- On ground/water encounter with terrain/water, takeoff - aborted
  - airport facilities,runway marking - inadequate (contributing factor)
  - planning/decision - improper, pilot in command (cause)
  - airport facilities,runway/landing area condition - snow covered (contributing factor)
  - terrain condition - snow covered (contributing factor)
  - weather condition - whiteout (contributing factor)
  - proper alignment - not possible, pilot in command
  - aborted takeoff
  - terrain condition - snowbank (contributing factor)

## Analysis

OPER PSNL RPRTD THAT DURING THE TAKEOFF ROLL, THE PLT ENCTRD PARTIAL WHITEOUT CONDITIONS & HAD DIFFICULTY DEFINING THE EDGE OF THE RWY FROM ADJACENT SNOW BERMS.  HE ABORTED THE TAKEOFF, BUT THE ACFT ENCTRD A SNOW BERM ON THE LEFT. IT THEN VEERED FURTHER LEFT & WAS DAMAGED.  ORANGE MARKERS HAD BEEN PLACED AT THE RWY EDGES, BUT THEY WERE LOCATED ALONG THE OUTSIDE EDGES OF THE BERMS & WERE NOT CLEARLY VISIBLE TO THE PLT.

## Aircraft

- Registration: [N9720M](https://openairdocs.org/aircraft/N9720M), registered now, S/N 20700720, built 1981 (OpenAirDocs)
- Reported make and model: CESSNA 207A
- Registry model: [Cessna 207A](https://openairdocs.org/model/cessna-207a) (registry code 2073605) (OpenAirDocs)
- Registry engine: [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f) (registry code 17237, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 20700720
- Airframe hours: 3637
- Engines: CONTINENTAL IO-520-F13 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Iliamna Air Taxi
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, November 14, 1989, 85 hours before
- Flight plan: VFR
- Airport: SNN, Nondalton, runway 20, 2,700 × 60 ft, gravel

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 13,069 total, 2,000 in this make and model, 12,734 as pilot in command, 151 in the last 90 days, 66 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 3 statute miles
- Lowest ceiling: 800 ft broken
- Temperature: 25 °F, dew point 19 °F
- Altimeter: 29.00 inHg

## 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 19900112000469A](https://openairdocs.org/incident/19900112000469A), Jan 12, 1990: Cessna 207A, Nondalton, AK, Substantial damage. Aborted takeoff due to whiteout condition that obscured orange runway markers. Wheel hit snow berm. Impacted berm.

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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