# NTSB SEA91FA027: Aero Commander 690A, N400N, Ryderwood, WA, December 1, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: November 30, 1990, 18:41 local (Dec 1, 1990, 02:41 UTC)
- Place: Ryderwood, WA
- Coordinates: 46.359169, -123.069396 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.3592&lon=-123.0694&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 5 fatal, 1 serious
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41299
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91FA027
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41299/pdf
- Page: https://openairdocs.org/ntsb/SEA91FA027

## Probable cause

THE PILOT'S IMPROPER INFLIGHT PLANNING AND FAILURE TO MAINTAIN PROPER ALTITUDE IN MOUNTAINOUS TERRAIN AT NIGHT.

## Sequence of events

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

- In flight collision with terrain/water, descent
  - in-flight planning/decision - improper, pilot in command (cause)
  - light condition - dark night (contributing factor)
  - terrain condition - mountainous/hilly (contributing factor)
  - proper altitude - not maintained, pilot in command (cause)

## Analysis

AS THE FLT WAS APCHG THE DESTN, AT NGT, THE PLT OBTAINED VECTORS FOR A DSCNT OVER MOUNTAINOUS TERRAIN. DURING THE APCH, HE CANCELLED THE IFR FLT PLAN & THE ACFT DSNDD BELOW RADAR COVERAGE. SUBSEQUENTLY, THE ACFT CRASHED IN MOUNTAINOUS TERRAIN, NORTHWEST OF THE DESTN ARPT. IMPACT OCCURRED IN A WOODED AREA AT AN ELEVATION OF ABOUT 2700 FT. THE ELT DID NOT ACTIVATE DURING THE ACDNT. A SEARCH WAS INITIATED ON 12/1/90, BUT THE ACFT & SURVIVING PASSENGER WERE NOT FND UNTIL THE NEXT DAY. THE CANADIAN ATP PLT & OTHER 4 PASSENGERS WERE FATALLY INJURED. AFTER INITIAL IMPACT WITH TREES, THE MAIN PORTION OF THE FUSELAGE TRAVELED ABOUT 1000 FT BEFORE COMING TO REST. NO PREIMPACT MECHANICAL PROBLEM WAS FOUND.

## Aircraft

- Registration: [N400N](https://openairdocs.org/deregistered/N400N-1991-04-10), registration cancelled 1991-04-10, S/N 11156 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 690A
- Registry model: [Aero Commander 690A](https://openairdocs.org/model/aero-commander-690a) (registry code 0141722) (OpenAirDocs)
- Category: Airplane
- Serial number: 11156
- Engines: GARRETT TPE-331 717 horsepower turbo prop
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Aero Air
- Destination: KLS, KELSO, WA
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; airline transport, commercial; airplane ratings: single-engine sea, multi-engine land, single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; toxicology performed; flight hours: 11,714 total, 2,647 in this make and model, 10,976 as pilot in command, 51 in the last 90 days, 22 in the last 30 days

## Weather

- Conditions: Visual (VMC), Night/dark
- Visibility: 10 statute miles
- Lowest ceiling: 1,200 ft broken
- Temperature: -0 °F, dew point -0 °F
- Altimeter: 30.00 inHg
- Observed at: KLS, 16 nm away

## 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 19901130052259A](https://openairdocs.org/incident/19901130052259A), Nov 30, 1990: Gulstm 690A, Ryderwood, WA, Destroyed, 5 fatal. Cancelled IFR on ground contact. Descending to land struck trees on unlighted hill. Airport surrounded by mountains

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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