# NTSB DEN83FA131: Aero Commander 680FL, N271VT, Monticello, UT, June 2, 1983

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 2, 1983, 17:23 local (23:23 UTC)
- Place: Monticello, UT
- Coordinates: 37.979999, -109.289863 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.9800&lon=-109.2899&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 15991
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN83FA131
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15991/pdf
- Page: https://openairdocs.org/ntsb/DEN83FA131

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, cruise - normal
  - fluid,fuel - starvation (contributing factor)
  - fuel tank selector position - delayed, pilot in command (cause)
  - inattentive, pilot in command (cause)
  - fuel boost pump selector position - not selected, pilot in command (cause)
  - diverted attention, pilot in command (cause)
  - in-flight planning/decision - improper, pilot in command (cause)
- Loss of control - in flight, cruise - normal
  - airspeed(vmc) - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE ACFT CRASHED WHILE DOING MAGNETOMETER SURVEYS AT LOW ALTITUDE. THE RIGHT ENGINE HAD LOST POWER THEN REGAINED IT FOR A SHORT PERIOD AND LOST IT AGAIN. A VIDEOTAPE IN THE ACFT RECORDED THE PLT SAYING, 'I CHANGED THAT # JUST IN TIME.' THE ACFT YAWED AND THE PROPELLER SLOWED AT THE SAME TIME. THE FUEL SELECTOR VALVES WERE FOUND ON THE CENTER TANKS. THE BOOST PUMP SWITCHES WERE FOUND IN THE OFF POSITION. WHEN CHANGING FROM OUTBOARD TO CENTER TANKS THE BOOST PUMPS MUST BE ON OR FUEL STARVATION WILL OCCUR. AS THE ACFT SLOWED THE TAPE REVEALED THAT THE CO-PLT CALLED OUT'DOWN TO 90'. 90 MPH ISVMC. THE ACFT STALLED, SHORTLY AFTER THE ASYMMETRICAL THRUST ROLLED THE ACFT TO THE RIGHT AND INTO THE GROUND.

## Aircraft

- Registration: [N271VT](https://openairdocs.org/deregistered/N271VT-2012-09-20), registration cancelled 2012-09-20, S/N 1435-74, built 1964 (OpenAirDocs)
- Reported make and model: AERO COMMANDER 680FL
- Registry model: [Aero Commander 680FL](https://openairdocs.org/model/aero-commander-680fl) (registry code 0141608) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Airplane
- Serial number: 1435-74
- Engines: LYCOMING IGSO-540-B1A 380 horsepower reciprocating
- Damage: Destroyed
- Flight: Business, Part 91
- Registered owner: Geodata International,Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, January 6, 1983
- Departed: CEZ, CORTEZ, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 1, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 12,200 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 12 knots, gusting 20
- Visibility: 50 statute miles
- Lowest ceiling: 12,000 ft broken
- Temperature: 63 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: CEZ, 34 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 19830602022529A](https://openairdocs.org/incident/19830602022529A), Jun 2, 1983: Gulstm 680FL, Monticello, UT, Destroyed. Aircraft crashed during low level magnetometer survey operations. Cause undetermined.

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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