# NTSB FTW85FA112: Cessna 402B, N5780M, Altus, OK, February 6, 1985

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 6, 1985, 09:43 local (15:43 UTC)
- Place: Altus, OK
- Coordinates: 34.639289, -99.310813 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.6393&lon=-99.3108&mi=10
- Phase of flight: [Unknown](https://openairdocs.org/ntsb-phases/990) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- Safety recommendations: Yes
- ADs cited in the narratives: [AD 75-23-08 R5](https://openairdocs.org/ad/75-23-08-R5) (OpenAirDocs)
- NTSB case key (mKey): 21526
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85FA112
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21526/pdf
- Page: https://openairdocs.org/ntsb/FTW85FA112

## Sequence of events

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

- Airframe/component/system failure/malfunction, unknown
  - exhaust system,manifold/pipe - corroded (cause)
  - maintenance,inspection - inadequate (cause)
  - procedure inadequate, manufacturer (contributing factor)
  - inadequate surveillance of operation, faa(organization) (contributing factor)
  - exhaust system,manifold/pipe - failure,total (cause)
  - exhaust system,manifold/pipe - leak (cause)
- Fire, climb - to cruise
  - miscellaneous - fire (cause)
- Loss of control - in flight, approach - vfr pattern - final approach
  - reason for occurrence undetermined (cause)
  - weather condition - clouds (contributing factor)
  - initiated, pilot in command
  - precautionary landing - attempted, pilot in command
  - aircraft handling - not maintained
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

DURING AN ENG START, PRIOR TO THE FLT, THE L ENG BACKFIRED 2 OR 3 TIMES. A WITNESS DESCRIBED THE 1ST BACKFIRED AS 'THE LOUDEST I HAVE EVER HEARD.' WHEN THE ACFT TOOK OFF, TWO PERSONS LIVING NEAR THE DEPARTURE END OF THE RWY NOTED THAT THE ACFT (BELIEVED TO BE THE SAME) SOUNDED DIFFERENT & HAD A 'CLUTTERING SOUND. 'WHILE CLIMBING, THE PLT DECLARED AN EMERGENCY & REPORTED A FIRE IN THE L ENG. HE WAS VECTORED TOWARD ALTUS AFB WHILE DSCNDG IN IFR CONDITIONS. HE DSCNDD INTO VFR CONDITIONS & SAW THE ARPT ABOUT 3 MI AWAY. A WITNESS SAW SMOKE & FIRE TRAILING FROM THE VICINITY OF THE L ENG. HE STATED THAT THE ACFT'S NOSE CAME UP, THE PLANE ROLLED TO THE LEFT, THEN IT ENTERED A STEEP, NOSE DOWN, INVERTED ATTITUDE JUST BEFORE IT CRASHED & BURNED. AN EXAM REVEALED THE ENG EXHAUST MAINIFOLD HEADER ASSY HAD FAILED & ALLOWED HOT EXHAUST GASES TO ESCAPE IN THE ENG NACELLE IN THE VICINITY OF FUEL & OIL LINES. CORROSION HAD PROGRESSED THRU THE HEADER ASSY. AD 75-23-08 REQD GEN INSPN, BUT CONTAINED NOTE 'DO NOT REMOVE CLAMPS.' NO RECORD OF REPLACEMENT IN 6100 HRS

## Aircraft

- Registration: N5780M (not matched to a registry record)
- Reported make and model: CESSNA 402B
- Category: Airplane
- Serial number: 402B-0348
- Airframe hours: 6100
- Engines: CONTINENTAL TSIO-520-E 300 horsepower reciprocating
- Damage: Destroyed
- Fire: In-Flight
- Flight: Part 135
- Operator: Altus Airline, Inc.
- Registered owner: Altus Airline, Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, January 10, 1985, 15 hours before
- Departed: AXS, ALTUS, OK
- Destination: OKC, OKLAHOMA CITY, OK
- Flight plan: IFR
- Airport: LTS, Altus Afb, runway 17

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; airline transport; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 4,227 total, 643 in this make and model, 3,762 as pilot in command, 71 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 80° at 9 knots
- Visibility: 3 statute miles
- Lowest ceiling: 1,100 ft broken
- Temperature: 28 °F, dew point 25 °F
- Altimeter: 30.00 inHg
- Observed at: LTS, 15 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 19850206069939A](https://openairdocs.org/incident/19850206069939A), Feb 6, 1985: Cessna 402B, Altus, OK, Destroyed, 1 fatal. Fire in left engine during climb. Impacted ground inverted. Exhaust pipe separated, ignited oil or fuel leak.

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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