ANC14LA054

NTSB accident investigation · Cessna 180H · Seward, AK · July 14, 2014

Accident · No injuriesLimited investigationFinal report
Date
July 14, 2014, 09:30 local (17:30 UTC)
Place
Seward, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9083MCessna 180H
Defining event
Landing-landing roll: Landing gear collapse
Weather
Visual (VMC) · Day
Status
Completed · report March 2, 2016
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
Federal Aviation Administration
FAA report
20140714010629A
Case key
89667

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

On this page

Probable cause

The pilot’s execution of a hard uncoordinated landing, which resulted in the overstress fracture of the right main landing gear (MLG) axle attachment bolts and the subsequent separation of the of the right MLG axle.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotCessna 180H: 32 casesAll aircraft: 9,295 casesProbable cause
Landing gear system: main gear strut/axle/truckAircraft › Aircraft systems · Capability exceededCessna 180H: 1 caseAll aircraft: 86 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The private pilot was landing his tailwheel-equipped airplane on a remote tidal beach. The pilot reported that, upon touchdown, the airplane bounced slightly before settling on the right main landing gear (MLG). In an effort to correct for the right-wing-low landing, the pilot applied left aileron, but the right wing continued to descend. The right MLG wheel axle separated from the gear leg, and the airplane slid along the beach, which resulted in substantial damage to the right wing and fuselage. Examination of the four right MLG attachment bolts revealed features consistent with an overload on the MLG axle. Therefore, it is likely the pilot executed a hard uncoordinated landing, which resulted in the separation of the right MLG axle upon landing.

Factual narrative

On July 14, 2014, about 0930 Alaska daylight time, a Cessna 180H airplane, N9083M, sustained substantial damage while landing on a beach on Montague Island, about 60 miles east of Seward, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The certificated private pilot, and the sole passenger were not injured. Visual meteorological conditions prevailed and a VFR flight plan had been filed. The flight departed Wolf Lake Airport, Palmer, Alaska at approximately 0835. In a written report to the National Transportation Safety Board dated July 20, the pilot reported that he was landing on the beach at Patton Bay on the east side of Montague Island. Upon touchdown the airplane bounced slightly before settling on the right main landing gear. In an effort to correct for the right wing low landing the pilot applied left aileron, but the right wing continued to descend. The right main wheel separated from the gear leg, and the airplane slid along the surface sustaining substantial damage to the right wing and fuselage. A postaccident examination, by the pilot, revealed that the right main landing gear axle separated from the gear leg. The axle and its four attaching bolts were sent to the NTSB's Materials Laboratory in Washington D.C. for examination. A Senior Safety Board Materials Engineer reported that the two forward attachment bolts, were bent slightly aft and exhibited longitudinal wear marks near the end of the threaded section with helical strips of metal present near the middle of the threaded section. The two aft bolts were bent aft, and the fractured surfaces were consistent with an overstress fracture. A complete copy of the NTSB's materials laboratory factual report is included in the public docket for this accident.

Aircraft

Registration
N9083M
Reported as
Cessna 180H
Category
Airplane
Serial number
18052183
Built
1971
Engine
Cont Motor O-470 SERIES, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Thomas Allen C
Registered owner
Thomas Allen C
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 6, 2014 · 4,841 hours before
Departed
4AK6 · Palmer, AK
Destination
Seward, AK
Flight plan
VFR
Equipment
Stall warning system

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
57
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Last flight review
August 26, 2013
Seat
Left
Restraint
3-point
Flight hours
1,309 total · 120 in this make and model · 1,293 as pilot in command · 23 in the last 90 days

Weather

Conditions
Visual (VMC) · Day
Wind
170° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
55 °F, dew point 48 °F
Altimeter
30.30 inHg
Observed at
PAWD, 60 nm away

Docket · 2

The files NTSB released with the investigation on January 27, 2016, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 MB in all.

FAA reports on this event · 1

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

Other investigations on N9083M · 2

Matched to the same aircraft by N-number and date.