ANC98LA027

NTSB accident investigation · Cessna A185F · Homer, AK · March 21, 1998

Accident · No injuriesLimited investigationFinal report
Date
March 21, 1998, 10:40 local (14:40 UTC)
Place
Homer, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9620QCessna A185F
Weather
Visual (VMC) · Day
Status
Completed · report February 15, 2001
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19980321004109A
Case key
3120

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.

The pilot's failure to maintain directional control. Factors in the accident are the sheared valve stem/deflation of the tire, and subsequent fracturing of the associated wheel.

Analysis

The airplane bounced once during landing on the dry, paved runway. The pilot stated that as the airplane settled, the left wheel began to vibrate, and then the airplane ground looped to the left. Postaccident inspection revealed the inner tube inflation valve stem sheared off, and the wheel halves fractured. No preaccident mechanical anomalies were discovered during the inspection. The wheels had been installed 4.5 service hours, and 7 landings prior to the accident.

Factual narrative

On March 21, 1998, at 1040 Alaska standard time, a Cessna A185F airplane, N9620Q, sustained substantial damage when it ground looped on landing at the Homer, Alaska, airport. The private pilot and the one passenger were uninjured. The airplane was operated by Fairweather, Inc., of Anchorage, Alaska. The flight was conducted under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident, and a VFR flight plan was filed. The flight departed Anchorage at 1001, bound for Homer.

The pilot stated during a telephone interview with the NTSB investigator-in-charge, and in his Pilot/Operator report, that during landing on the dry asphalt runway, the airplane bounced once, and after settling onto the runway, the left wheel began to vibrate. He indicated that as the airplane was decelerating, he retracted flaps and the airplane began drifting to the left. Application of right rudder did not stop the drift, the airplane ground looped to the left, and the right wing struck the runway. The airplane came to rest on the runway.

The pilot, and the mechanics who repaired the airplane, said that the valve stem of the tire's inner tube was observed to be sheared off. Postaccident inspection of the wheel by the NTSB investigator revealed that both left wheel halves had fractured into numerous pieces. No preaccident anomalies were observed with the wheel or bearings. The Cleveland wheel assemblies with 8.50 inch by 6 inch tires had been installed October 3, 1997, 7 landings and about 4.5 hours prior to the accident.

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.

Loss of control - on ground/waterLanding - roll
Ground loop/swerve - inadvertentPilot in commandCause
Landing gear,tire - shearedFactor
Landing gear,wheel - fracturedFactor

Aircraft

Registration
N9620Q
Reported as
Cessna A185F
Category
Airplane
Serial number
185-03780
Airframe hours
1,615
Engine
Continental IO-520-D, 350 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Fairweather, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 5, 1997 · 31 hours before
Departed
ANC · Anchorage, AK
Destination
HOM
Flight plan
VFR
Airport
HOM · Homer, runway 21, 7,401 × 150 ft, asphalt

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 sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
687 total · 594 in this make and model · 601 as pilot in command · 5 in the last 90 days · 5 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
110° at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
41 °F, dew point 36 °F
Altimeter
30.00 inHg
Observed at
HOM

FAA reports on this event · 1

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