ANC01TA032

NTSB accident investigation · Cessna 172 · Kipnuk, AK · January 23, 2001

Accident · No injuriesFinal report
Date
January 23, 2001, 13:30 local (17:30 UTC)
Place
Kipnuk, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N737CUCessna 172
Weather
Visual (VMC) · Day
Status
Completed · report July 30, 2001
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA, ANC FSDO
FAA report
20010123038609A
Case key
51386

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 inadequate compensation for a crosswind during the landing roll. Factors in the accident were the presence of a crosswind, an icy runway and snow covered terrain, the pilot's inadequate preflight planning/preparation, and an inaccurate wind direction indicator.

Analysis

The private certificated pilot/owner was landing at a remote airport. The purpose of the flight was to work on the FAA's VOR building at the destination airport. The pilot is an employee of the FAA's Airways Facilities Branch. The pilot said that his check of weather conditions included a wind report of 060 degrees at eight knots. Upon arrival over the airport, the pilot said he visually checked the wind sock at the airport. The wind sock frame appeared to be oriented about 150 degrees, but the tail of the sock was blowing at an angle. The wind appeared to be 060 degrees at 10 knots, with gusts to 15 knots. The pilot landed on runway 33, touching down at the approach end of the runway. The runway surface was icy, and about 300 feet after touchdown, the airplane was blown to the left. The pilot was unable to correct the left drift, and the airplane departed the left side of the runway, into an area of soft snow. The airplane nosed over, and received damage to the wings and vertical stabilizer. The remarks section of the airport facility directory/Alaska supplement notes that the airport is unattended, the runway condition is not monitored, the airport has frequent crosswinds, and the windsock at the south end of the airport is damaged, and not functioning properly.

Factual narrative

On January 23, 2001, about 1330 Alaska standard time, a Cessna 172 airplane, N737CU, sustained substantial damage during landing at Kipnuk, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country government flight under Title 14, CFR Part 91, when the accident occurred. The airplane was owned by the pilot, and operated by the Federal Aviation Administration (FAA), Airways Facilities Branch, Anchorage, Alaska. The private certificated pilot, and the sole passenger, were not injured. Visual meteorological conditions prevailed. The flight originated at the Bethel Airport, Bethel, Alaska, about 1230.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on January 24, 2001, the pilot reported that he and the passenger are employees of the FAA, Airways Facilities Branch. The flight to Kipnuk was for the purpose of working on the VOR building at Kipnuk. The pilot said that his check of weather conditions at Kipnuk included a wind report of 060 degrees at eight knots. Upon arrival over the airport, the pilot said he visually checked the wind sock at the airport. The wind sock frame appeared to be oriented about 150 degrees, but the tail of the sock was blowing at an angle. The wind appeared to be 060 degrees at 10 knots, with gusts to 15 knots. The pilot landed on runway 33, touching down at the approach end of the runway. The runway surface was icy, and about 300 feet after touchdown, the airplane was blown to the left. The pilot was unable to correct the left drift, and the airplane departed the left side of the runway, into an area of soft snow. The airplane nosed over, and received damage to the wings and vertical stabilizer.

The pilot reported that he utilized his personal airplane as transportation to Kipnuk, receiving mileage compensation from the FAA.

The FAA's Airport Facility Directory/Alaska Supplement listing for the Kipnuk airport includes airport remarks, which state, in part: "Airport unattended. Caution, runway condition not monitored, recommend visual inspection prior to using. Caution, frequent crosswinds. ...windsock at south end of airport damaged, not functioning properly."

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.

On ground/water encounter with weatherLanding - roll
Preflight planning/preparation - inadequatePilot in commandFactor
Airport facilities,wind direction indicator - inaccurateFactor
Weather condition - crosswindFactor
Loss of control - on ground/waterLanding - roll
Compensation for wind conditions - inadequatePilot in commandCause
Airport facilities,runway/landing area condition - icyFactor
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - snow coveredFactor
Nose overLanding - roll

Aircraft

Registration
N737CU
Reported as
Cessna 172
Category
Airplane
Serial number
17269321
Airframe hours
988
Engine
Lycoming O-320-E2D, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Public aircraft · Part 91
Operator
Federal Aviation Administration
Registered owner
Lance Miller
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 9, 2000 · 80 hours before
Departed
PABE · Bethel, AK
Destination
PAKI · Kipnuk, AK
Airport
PAKI · Kipnuk, runway 33, 2,120 × 35 ft, gravel

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
38
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
128 total · 126 in this make and model · 82 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
60° at 8 knots, gusting 15
Visibility
10 statute miles
Lowest ceiling
4,500 ft overcast
Temperature
19 °F
Altimeter
29.44 inHg

FAA reports on this event · 1

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