# NTSB DEN87FA016: Cessna 421C, N421AR, Butte, MT, November 6, 1986

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: November 6, 1986, 04:36 local (11:36 UTC)
- Place: Butte, MT
- Location: 46.0038° N, 112.5347° W: Placed by OpenAirDocs: center of Butte, MT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=46.0038&lon=-112.5347&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report March 10, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 17080
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN87FA016
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17080/pdf
- Page: https://openairdocs.org/ntsb/DEN87FA016

## Sequence of events

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

- In flight encounter with weather, approach
  - weather condition - low ceiling (contributing factor)
  - in-flight planning/decision - poor, pilot in command (cause)
  - weather condition - snow (contributing factor)
  - ifr procedure - not followed, pilot in command (cause)
- In flight collision with terrain/water, approach
  - terrain condition - mountainous/hilly (contributing factor)
  - altitude - improper, pilot in command (cause)
  - clearance - not possible, pilot in command (cause)
  - visual/aural perception, pilot in command (contributing factor)

## Analysis

PLT WAS ATTEMPTING THE VOR-B INSTRUMENT APCH TO BUTTE, MT ARPT. PLT REPORTED OVER THE COPPERTOWN VORTAC INBOUND ON THE ARPT. THE PROCEDURE TURN INBOUND COURSE TO THE VORTAC IS 124 DEGREES. THE INBOUND COURSE TO THE ARPT IS 094 DEGREES. THE ACFT WRECKAGE WAS FOUND ON THE 124 DEGREE RADIAL 5 MILES SW OF THE ARPT. THE WIND WAS REPORTED TO BE 340 DEGREES AT 9 KTS. THE VOR-B APCH TERMINATES AT RWY 11. RWY 33 IS 9000 FT LONG AND EQUIPPED WITH MIRL'S AND REIL'S.

## Aircraft

- Registration: [N421AR](https://openairdocs.org/aircraft/N421AR), registered now, S/N 421C0904 (OpenAirDocs)
- Reported make and model: CESSNA 421C
- Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs)
- Registry engine: [Continental GTSIO-520 series](https://openairdocs.org/engine/continental-gtsio-520-series) (registry code 17046, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 421C0254
- Airframe hours: 2890
- Engines: CONTINENTAL GTSIO-520-L 375 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Part 135
- Registered owner: Lynch Flying Service
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, October 20, 1986, 50 hours before
- Departed: HLN, HELENA, MT
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 35; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 4,000 total

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: 340° at 9 knots
- Visibility: 2 statute miles
- Lowest ceiling: 1,100 ft
- Temperature: 28 °F, dew point 27 °F
- Altimeter: 29.00 inHg
- Observed at: BTM, 5 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 19861106054309A](https://openairdocs.org/incident/19861106054309A), Nov 6, 1986: Cessna 421C, Butte, MT, Destroyed. The aircraft struck trees during a VOR approach. Weather was below minimums and aircraft descended below mda.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.