# NTSB DEN84MA266: Aero Commander 690, N9150N, Little America, WY, August 25, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Major investigation · Final report
- Date: August 25, 1984, 10:30 local (16:30 UTC)
- Place: Little America, WY
- Coordinates: 41.550662, -109.859161 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.5507&lon=-109.8592&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 4 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16502
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN84MA266
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16502/pdf
- Page: https://openairdocs.org/ntsb/DEN84MA266

## Sequence of events

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

- In flight encounter with weather, cruise
  - weather condition - clouds (contributing factor)
  - weather condition - thunderstorm (contributing factor)
  - weather condition - turbulence in clouds (contributing factor)
  - weather condition - rain (contributing factor)
  - weather condition - low ceiling (contributing factor)
  - weather condition - icing conditions (contributing factor)
  - flight into known adverse weather - continued, pilot in command (cause)
- Loss of control - in flight, cruise
  - aircraft handling - not maintained
- Airframe/component/system failure/malfunction, descent - uncontrolled
  - design stress limits of aircraft - exceeded
  - wing - overload
  - fuel system,tank - overload
- Fire, descent - uncontrolled
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

ABOUT 10 MIN AFTER TAKEOFF AT 1005 MDT, THE PLT WAS CLEARED TO CLIMB TO FL 190. THIS WAS ATC'S LAST COMMUNICATION WITH THE ACFT. AT 1030:39, THE CONTROLLER ATTEMPTED TO CONTACT THE PLT TO ADVISE THAT HE HAD LOST RADAR CONTACT & TO RECYCLE THE TRANSPONDER & SQUAWK 6062. THERE WAS NO RESPONSE. TWO WITNESSES REPORTED SEEING THE ACFT JUST BEFORE IT IMPACTED THE GROUND. ACCORDING TO THEM, THEY SAW FIRE &/OR AN EXPLOSION BEFORE IMPACT & ONE WITNESS REPORTED THE ACFT BROKE UP AFTER IT CAME BELOW AN ESTIMATED 1000 TO 1200 FT CEILING. HOWEVER, THE WRECKAGE WAS SCATTERED OVER A 2 MI AREA. AN EXAM REVEALED EVIDENCE OF A CATASTROPHIC IN-FLT BREAKUP FROM OVERLOAD WHICH INCLUDED POSITIVE OVERLOAD OF BOTH WINGS. RADAR DATA SHOWED THAT JUST BEFORE RADAR CONTACT WAS LOST, THE ACFT'S SPEED VARIED BETEEN 221 & 272 KTS, HEADING VARIED FROM 072 TO 014 DEG & VERTICAL VELOCITY VARIED FROM +300 TO -2400 FT/MIN. THUNDERSTORMS, TURBC, RAIN & CLD TOPS TO 25,000' WERE REPORTED. PROBABLE LGT TO MOD ICING IN CLDS ABOVE THE FREEZING LVL (14,000'). ACFT HAD WX RADAR ABOARD.

## Aircraft

- Registration: [N9150N](https://openairdocs.org/deregistered/N9150N-2013-05-22), registration cancelled 2013-05-22, S/N 11063, built 1973 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 690
- Registry model: [Aero Commander 690](https://openairdocs.org/model/aero-commander-690) (registry code 0141720) (OpenAirDocs)
- Registry engine: [AiResearch TPE331 series](https://openairdocs.org/engine/airesearch-tpe331-series) (registry code 01514, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 11063
- Engines: GARRETT TPE 331 718 horsepower turbo prop
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Registered owner: Dr. James P. Demetry
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, March 14, 1984
- Departed: OGD, OGDEN, UT
- Destination: ARR, AURORA, IL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; commercial, private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 3,410 total, 10 in the last 90 days

## Weather

- Conditions: Day
- Temperature: 70 °F, dew point 50 °F
- Altimeter: 30.00 inHg
- Observed at: RKS, 57 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 19840825043339A](https://openairdocs.org/incident/19840825043339A), Aug 25, 1984: Gulstm 690, Little America, WY, Destroyed, 3 fatal. Flew into area of icing and turbulence. Witnesses saw aircraft descend steeply ot of clouds and break up in flight.

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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