SEA98LA166

NTSB accident investigation · Cessna 175 · Missoula, MT · August 15, 1998

Accident · No injuriesLimited investigationFinal report
Date
August 15, 1998, 16:20 local (22:20 UTC)
Place
Missoula, MT
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N8512XCessna 175
Weather
Visual (VMC) · Day
Status
Completed · report February 15, 2001
Report
Approved by Office Director
FAA report
19980815031349A
Case key
43739

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

A complete loss of crankcase oil due to a missing oil filler tube followed by the failure of a connecting rod. Factors include encountering a small pine tree during the landing roll.

Analysis

While in cruise flight, the pilot smelled smoke and noticed a loss of oil pressure. He therefore found an open field in which he could make an emergency landing. After arriving over the field, the engine stopped running and the pilot made a forced landing. During the landing roll, the aircraft's nose gear was torn off when it hit a small pine tree. After the gear was torn off, the aircraft nosed over. A post-accident inspection of the engine revealed that the number three connecting rod had failed and passed through the crankcase. It was also noted that the oil filler tube was missing, and no oil was found in the crankcase.

Factual narrative

On August 15, 1998, approximately 1620 mountain daylight time, a Cessna 175, N8512X, nosed over during a power-off forced landing about 15 miles southwest of Missoula, Montana. The private pilot and his passenger were not injured, but the aircraft, which was owned and operated by Hinkle Aviation, of Caldwell, Idaho, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Kalispell, Montana, about 50 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation.

According to the pilot, while at cruise, smoke started accumulating in the cabin, so he started checking for abnormal instrument indications. Soon thereafter, he noticed that the oil pressure had dropped to zero. He then reversed course in order to return to an open field he had flown over a few minutes earlier. As he arrived over the field, the engine stopped running, and he attempted a forced landing. His touchdown was successful, but as the aircraft neared the edge of the field, the nose gear hit a small pine tree. When the gear hit the tree, the entire nose gear assembly was torn from the fuselage and the aircraft nosed over.

A post accident inspection of the engine revealed that the oil filler tube had separated from the engine and was not found at the accident site. Almost all of the engine oil had drained from the crankcase, and the number three connecting rod had failed and come through the side of the case.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionCruise
Fluid,oil - exhaustionCause
Engine assembly,connecting rod - fracturedCause
Forced landingEmergency descent/landing
Nose overLanding - roll
Object - tree(s)Factor

Aircraft

Registration
N8512X
Reported as
Cessna 175
Category
Airplane
Serial number
17557112
Airframe hours
1,999
Engine
Continental GO300-E, 175 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Bill Hinkle, doing business as Hinkle Aviation
Registered owner
Hinkle Aviation
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · July 25, 1998 · 20 hours before
Departed
S27 · Kalispell, MT
Destination
EUL · Caldwell, ID

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
48
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
77 total · 7 in this make and model · 35 as pilot in command · 7 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
45° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
84 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.