ANC00LA105

NTSB accident investigation · Cessna 185 · Yakutat, AK · August 17, 2000

Accident · No injuriesLimited investigationFinal report
Date
August 16, 2000, 17:00 local (Aug 17, 2000, 01:00 UTC)
Place
Yakutat, AK
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N185MCessna 185
Weather
Visual (VMC) · Day
Status
Completed · report July 2, 2001
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
20000816042379A
Case key
50984

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 total fatigue failure of the right main landing gear leg.

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/malfunctionLanding - flare/touchdown
Landing gear,main gear strut - failure,totalCause
Landing gear,main gear strut - fatigueCause
On ground/water encounter with terrain/waterLanding - flare/touchdown

Analysis

The pilot said that during landing on firm sand, the right landing gear leg separated at the wheel attachment upper bolts. The remaining gear leg dug into the sand, and the airplane spun around. The airplane sustained substantial damage to both main landing gear attachments, and both wings. The NTSB materials laboratory found areas of fatigue at both upper bolt holes. Corrosion pitting was found at one of the fatigue sites. The airplane had been operated on skis in the past.

Factual narrative

On August 16, 2000, about 1700 Alaska daylight time, a tundra tire equipped Cessna 185 airplane, N185M, sustained substantial damage during landing at an off airport landing site on the Alsek River, Alaska, at 59 degrees, 04 minutes north latitude, 138 degrees, 19 minutes west longitude. The commercial pilot and the two passengers were not injured. The flight was conducted under 14 CFR Part 135, by Mountain Flying Service, Inc., of Haines, Alaska, as an on demand sightseeing flight. The flight originated from Haines, Alaska, about 1500, with a planned landing at the accident site. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed.

The pilot told the NTSB investigator-in-charge during a telephone interview on August 21, that during the landing on firm sand, the right landing gear leg separated at the wheel attachment upper bolts. The remaining gear leg dug into the sand, and the airplane spun around. The airplane sustained substantial damage to both main landing gear attachments, and both wings.

The fractured lower leg was examined at the NTSB materials laboratory on September 12, 2000. Areas of fatigue were found at both upper bolt holes. Corrosion pitting was found at one of the fatigue sites. Pink, non-destructive inspection, dye penetrant residue was found inside the bolt holes. A review of the airplane's logbooks revealed that the airplane had been operated on skis in the past.

Aircraft

Registration
N185M
Reported as
Cessna 185
Category
Airplane
Serial number
18504264
Airframe hours
6,500
Engine
Continental IO-520, 300 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Registered owner
Paul Swanstrom
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · August 3, 2000 · 50 hours before
Departed
HNS · Haines, AK
Flight plan
VFR

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
45
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
5,000 total · 4,500 in this make and model · 300 in the last 90 days · 100 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
270° at 5 knots
Visibility
40 statute miles
Lowest ceiling
None
Temperature
61 °F

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 N185M · 2

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