# NTSB ANC87LA091: Dornier DO-27, N777AX, White Mountain, AK, July 6, 1987

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 6, 1987, 09:00 local (17:00 UTC)
- Place: White Mountain, AK
- Coordinates: 64.680641, -163.409484 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=64.6806&lon=-163.4095&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report May 9, 1988
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 4867
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC87LA091
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/4867/pdf
- Page: https://openairdocs.org/ntsb/ANC87LA091

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise
  - engine assembly,cylinder - failure,total (cause)
  - engine assembly,cylinder - separation (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing - flare/touchdown

## Analysis

THE PILOT STATED THAT WHILE CRUISING AT 2000 FEET MSL THE ENGINE STARTED TO RUN ROUGH. HE MADE AN EMERGENCY LANDING ON THE TUNDRA. EXAMINATION OF THE ENGINE REVEALED THE NUMBER ONE AND NUMBER TWO CYLINDERS BROKE AND SEPARATED IN FLIGHT.

## Aircraft

- Registration: [N777AX](https://openairdocs.org/deregistered/N777AX-1993-02-19), registration cancelled 1993-02-19, S/N 458 (OpenAirDocs)
- Reported make and model: DORNIER DO-27
- Registry model: [Dornier DO 27 A5](https://openairdocs.org/model/dornier-do-27-a5) (registry code 2990705) (OpenAirDocs)
- Category: Airplane
- Serial number: 458
- Airframe hours: 1914
- Engines: LYCOMING GO-480-B1A6 295 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: William S. Munz
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 10, 1987, 2 hours before
- Departed: OMILAK, AK

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 77; private; airplane ratings: multi-engine land, single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 19,731 total, 88 in this make and model, 19,680 as pilot in command, 26 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 100 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 39 °F
- Altimeter: 29.00 inHg

## 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 19870706033959A](https://openairdocs.org/incident/19870706033959A), Jul 6, 1987: Dorner DO27A4, White Mountain, AK, Substantial damage. The engine began breaking up and the aircraft landed in rough terrain. Suspect connecting rod failure.

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.