# NTSB ATL86FA085: Beech BE-90, N861K, Mount Pleasant, TN, March 4, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: March 4, 1986, 07:35 local (13:35 UTC)
- Place: Mount Pleasant, TN
- Coordinates: 35.619346, -87.039199 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.6193&lon=-87.0392&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 9 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6930
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL86FA085
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6930/pdf
- Page: https://openairdocs.org/ntsb/ATL86FA085

## Sequence of events

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

- Fire, approach - vfr pattern - final approach
  - air cond/heating/pressurization - overtemperature
  - reason for occurrence undetermined (cause)
  - fuel system,fuel shutoff - low compression (contributing factor)
  - air cond/heating/pressurization,cabin temp control - switched off (contributing factor)
  - fuselage,instrument/electrical panel - burned (contributing factor)

## Analysis

ON FINAL APPROACH THE CREW TURNED THE AIRCRAFT CABIN ENVIRONMENTAL CONTROL FROM THE AUTO MODE TO THE OFF POSITION. SHORTLY THEREAFTER, THE COCKPIT AND CABIN BEGAN TO FILL WITH SMOKE. THE OCCUPANT OF THE COPILOTS SEAT FELT HEAT AROUND HIS FEET. A NORMAL LANDING WAS MADE AND THE PASSENGERS AND CREW EXITED THE AIRCRAFT WITH OUT INJURY. EXAMINATION SHOWED THAT THE FIBERGLASS DUCTING ON TOP OF THE HEATER PELEUM CHAMBER HAD CAUGHT FIRE. A HOLE WAS BURNED THROUGHT THE PRESSURE BULKHEAD INTO THE AVIONICS COMPARTMENT.

## Aircraft

- Registration: N861K (not matched to a registry record)
- Reported make and model: BEECH BE-90
- Category: Airplane
- Serial number: LJ-471
- Airframe hours: 3781
- Engines: P&W PT6 A-20 550 horsepower turbo prop
- Damage: Substantial damage
- Fire: Both
- Flight: Part 135
- Operator: Stevens Aviation,Inc.
- Registered owner: The E. Randel Co.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, October 15, 1985, 64 hours before
- Departed: LOU, LOUISVILLE, KY
- Destination: MRC, COLUMBIA, TN
- Flight plan: IFR
- Airport: MRC, Maury County Airport, runway 23, 5,003 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; airline transport, flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 1, valid medical--no waivers/lim.; seat: right

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 6 knots
- Visibility: 5 statute miles
- Lowest ceiling: 4,000 ft overcast
- Temperature: 39 °F
- Altimeter: 30.00 inHg
- Observed at: BNA, 42 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 19860304007549A](https://openairdocs.org/incident/19860304007549A), Mar 4, 1986: Beech B90, Mount Pleasant, TN, Substantial damage. Smoke filled aircraft on final after heater was switched off. Heater had not been repaired or adjusted properly.

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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