# NTSB ANC86LA158: Cessna 207A, N9736M, Mountain Villag, AK, September 17, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 17, 1986, 12:20 local (20:20 UTC)
- Place: Mountain Villag, AK
- Coordinates: 62.089935, -163.710647 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.0899&lon=-163.7106&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 10, 1988
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4742
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC86LA158
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4742/pdf
- Page: https://openairdocs.org/ntsb/ANC86LA158

## Sequence of events

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

- Airframe/component/system failure/malfunction, landing - roll
  - landing gear,normal brake system - failure,partial (contributing factor)
  - operation with known deficiencies in equipment - attempted, pilot in command (cause)
  - hydraulic system,line - fatigue (contributing factor)
- Overrun, landing - roll
  - weather condition - crosswind (contributing factor)
  - compensation for wind conditions - inadequate, pilot in command (contributing factor)
  - proper touchdown point - not attained, pilot in command (contributing factor)
  - go-around - not performed, pilot in command (contributing factor)

## Analysis

THE AIRLINE TRANSPORT PILOT WHO IS ALSO A CERTIFICATED AIRFRAME AND POWERPLANT MECHANIC ELECTED TO DEFER BRAKE REPAIRS UNTIL THE END OF THE FLYING DAY. THE FATIGUED RIGHT BRAKE LINE FAILED BEFORE THE END OF THE DAY'S FLYING ACTIVITY. DURING LNDG THE BRAKES FAILED AND THE ACFT OVERRAN THE END OF THE RWY RESULTING IN SUBST DAMAGE

## Aircraft

- Registration: [N9736M](https://openairdocs.org/aircraft/N9736M), registered now, S/N 20700722, built 1981 (OpenAirDocs)
- Reported make and model: CESSNA 207A
- Registry model: [Cessna 207A](https://openairdocs.org/model/cessna-207a) (registry code 2073605) (OpenAirDocs)
- Registry engine: [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f) (registry code 17237, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 20700722
- Airframe hours: 4937
- Engines: CONTINENTAL IO-520F 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Ryan Air Service, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, September 5, 1986, 37 hours before
- Departed: KSM, ST. MARYS, AK
- Airport: MOU, Mountain Village, runway 34, 2,200 × 75 ft, gravel

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 2,579 total, 546 in this make and model, 2,526 as pilot in command, 318 in the last 90 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 110° at 13 knots
- Visibility: 20 statute miles
- Lowest ceiling: 1,000 ft broken
- Temperature: 48 °F, dew point 46 °F
- Altimeter: 29.00 inHg
- Observed at: KSM, 10 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 19860917045769A](https://openairdocs.org/incident/19860917045769A), Sep 17, 1986: Cessna 207A, Mountain Villag, AK, Substantial damage. The right brake failed. The aircraft overran the runway on landing. Leaking brake line failed from fatigue.

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.