# NTSB FTW85LA170: Cessna 175, N6710E, Sonora, TX, March 23, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: March 23, 1985, 13:00 local (19:00 UTC)
- Place: Sonora, TX
- Location: 30.5707° N, 100.6418° W: Placed by OpenAirDocs: center of Sonora, TX, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=30.5707&lon=-100.6418&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21713
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85LA170
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21713/pdf
- Page: https://openairdocs.org/ntsb/FTW85LA170

## 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, descent - normal
  - engine assembly,connecting rod - failure,total (cause)
  - maintenance,service of aircraft/equipment - improper, other maintenance personnel (cause)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - rough/uneven (cause)

## Analysis

THE ACFT WAS DESTROYED DURING A FORCED LANDING IN ROUGH TERRAIN, FOLLOWING AN ENG FAILURE IN-FLT. INVESTIGATION REVEALEDTHAT THE NO. 3 CONNECTING ROD FAILED DUE TO OIL STARVATION. THE ROD OIL PASSAGEWAY WAS FOUND CLOGGED WITH SLUDGE AND FINE METAL PARTICLES, AS WERE THE OIL FILTER AND SCREEN. IN ADDITION, SEVERAL BROKEN RINGS AND LEAKING INTAKE MANIFOLD HOSES WERE FOUND. THE ACFT WAS OPERATING ON AUTO GAS AND MARVEL MYSTERY OIL.

## Aircraft

- Registration: N6710E (not matched to a registry record)
- Reported make and model: CESSNA 175
- Category: Airplane
- Serial number: 56210
- Airframe hours: 2093
- Engines: CONTINENTAL GO-300-A 175 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: R & D Interests
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 12, 1984, 60 hours before
- Departed: SJT, SAN ANGELO, TX
- Destination: 07R, BISHOP, TX
- Flight plan: VFR
- Airport: Sonora

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; student; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 95 total, 88 in this make and model, 48 as pilot in command, 16 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 10 knots, gusting 12
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 10 °F

## 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 19850323011159A](https://openairdocs.org/incident/19850323011159A), Mar 23, 1985: Cessna 175, Sonora, TX, Destroyed. Oil filter, screen clogged by sludge, metals. Oil vented overboard. Landed in rocky field. Used marvel mystery oil.

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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