# NTSB SEA91LA249: Cessna 177, N3314T, Snohomish, WA, September 23, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 22, 1991, 19:15 local (Sep 23, 1991, 02:15 UTC)
- Place: Snohomish, WA
- Coordinates: 47.940086, -121.999786 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.9401&lon=-121.9998&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 5, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41546
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91LA249
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41546/pdf
- Page: https://openairdocs.org/ntsb/SEA91LA249

## Probable cause

THE SEPARATION OF THE MIXTURE CONTROL CABLE (CORE) RESULTING FROM SEPARATION OF THE ADEL CLAMP ASSEMBLY AND IMPROPER ADJUSTMENT BY MAINTENANCE PERSONNEL.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise - normal
  - miscellaneous - separation (contributing factor)
  - maintenance,adjustment - improper, company maintenance personnel (contributing factor)
  - mixture control,cable - separation (cause)
- Forced landing, descent - emergency
- Nose gear collapsed, landing - roll
  - terrain condition - rough/uneven (contributing factor)
  - landing gear,nose gear - overload

## Analysis

DURING CRUISE A PARTIAL POWER LOSS OCCURRED AND THE PILOT, UNABLE TO REACH A SUITABLE AIRPORT, EXECUTED A FORCED LANDING. POST CRASH EXAMINATION REVEALED THAT THE MIXTURE CONTROL CABLE CORE HAD SEPARATED AT THE MIXTURE CONTROL ARM BOLT ADJACENT TO THE CARBURETOR. ADDITIONALLY, THE ADEL CLAMP ASSEMBLY RETAINING THE MIXTURE CONTROL CABLE NEAR THE MIXTURE CONTROL ARM WAS OBSERVED TO BE SEPARATED. THE SEPARATED CABLE CORE WAS DUE TO REVERSE BENDING FATIGUE CRACKING CONSISTENT WITH EXCESSIVE VIBRATORY LOADS APPLIED TO THE CABLE AS A RESULT OF THE SEPARATED ADEL CLAMP ASSEMBLY. THE SEPARATED ADEL CLAMP WAS DUE TO EXCESSIVE TWISTING LOADS APPLIED TO THE CLAMP. DURING THE FORCED LANDING ROLLOUT, WHICH WAS EXECUTED ON ROUGH TERRAIN, THE NOSE WHEEL ASSEMBLY COLLAPSED.

## Aircraft

- Registration: [N3314T](https://openairdocs.org/deregistered/N3314T-2013-06-07), registration cancelled 2013-06-07, S/N 17700614, built 1967 (OpenAirDocs)
- Reported make and model: CESSNA 177
- Registry model: [Cessna 177](https://openairdocs.org/model/cessna-177) (registry code 2073704) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17700614
- Airframe hours: 3047
- Engines: LYCOMING O-360-A1A 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Sigmet Inc.
- Registered owner: Sigmet Inc.
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Last inspection: Continuous airworthiness, March 22, 1991, 303 hours before
- Departed: TIW, TACOMA, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 58; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 756 total, 220 in this make and model, 593 as pilot in command, 30 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Wind: 320° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: 15,000 ft overcast
- Temperature: 59 °F, dew point 50 °F
- Altimeter: 30.00 inHg
- Observed at: PAE, 7 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 19910922042109A](https://openairdocs.org/incident/19910922042109A), Sep 22, 1991: Cessna 177, Snohomish, WA, Substantial damage. Lost partial power. Nose gear collapsed in a ditch on landing. Mixture control cable clamp broke. Separated cable.

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.