ANC10LA021

NTSB accident investigation · Cessna U206G · Nanwalek, AK · March 5, 2010

Accident · No injuriesLimited investigationFinal report
Date
March 5, 2010, 16:30 local (20:30 UTC)
Place
Nanwalek, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N734JMCessna U206G
Defining event
Landing-landing roll: Runway excursion
Weather
Visual (VMC) · Day
Status
Completed · report April 28, 2011
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA/FSDO
FAA report
20100305028979A
Case key
75469

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 decision to land on a short, icy runway with poor braking action, resulting in a runway overrun/excursion and collision with a snowbank.

Findings · 3

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.

Aircraft capability: landing distanceAircraft › Aircraft oper/perf/capability · Capability exceededCessna U206G: 1 caseAll aircraft: 68 cases

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

Prior to touchdown on the snow and ice covered gravel runway with 850 feet of usable length, the pilot reported that the airplane floated a little, but the touchdown point and touchdown were normal. When he applied the brakes, he indicated that there was very little to no braking action. The airplane slid towards the right while in a left yaw, which he was able to correct when the braking action improved. The airplane continued to the end of the runway and impacted a snowbank. The pilot reported there were no preimpact mechanical problems with the airplane. He noted that he walked the runway after the accident, and determined that the braking action would have been slightly better had he landed in the opposite direction. The US Department of Transportation’s Alaska Airport Supplement indicates that the runway should be visually checked for condition before use.

Factual narrative

On March 5, 2010, about 1630 Alaska standard time, a Cessna U206G, N734JM, registered to and operated by Smokey Bay Air, Inc.,Homer, Alaska, collided with a snowbank during the landing roll at Nanwalek Airport, Nanwalek, Alaska. Visual meteorological conditions prevailed, and a company visual flight rules (VFR) flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 135, scheduled domestic passenger flight from the Homer Airport, Homer. The airplane sustained substantial damage to the left wing. The airline transport certificated pilot and the sole passenger were not injured. The flight originated from Homer about 1600. The pilot stated that the approach to runway 01 was normal, but the airplane floated a little before touchdown on the snow and ice covered gravel runway. The touchdown and touchdown point were normal, and during the landing roll he retracted the flaps and applied the brakes but later reported the braking action as “…very little to no braking action.” The airplane slid towards the right while in a left yaw, and he regained some braking action, correcting the left yaw. The airplane continued to the end of the runway and impacted a snowbank with the right main landing gear, causing the airplane to yaw to the right. The left main landing gear then contacted the snowbank, causing the left wing to drop and strike a snowbank. The pilot reported there was no preimpact mechanical failure or malfunction of the airplane or of its systems. He later walked the runway, and determined that the braking action would have been slightly better had he landed the other direction. The pilot, age 29, holds commercial, airline transport, and flight instructor pilot certificates. At the commercial level, he has airplane single engine land and sea ratings. His last first class medical certificate with no medical restrictions was issued October 29, 2009. The submitted NTSB Pilot/Operator Aircraft Accident/Incident Report indicated the pilots’ total time in all aircraft was 5,000 hours, and he listed having 1,500 hours in the accident make and model airplane. According to the operator's Director of Maintenance, six stringers in the left wing and the outer rib were damaged, requiring removal and replacement. The Nanwalek Airport is equipped with one runway designated 01/19. The US Department of Transportation's Alaska Airport Supplement indicates the gravel runway is 1,850 feet long and 50 feet wide, with the north 1,000 feet closed indefinitely. The supplement also notes that the approach to runway 01 is restricted by an abrupt mountain face located .21 nautical mile from the approach end, and the runway is not routinely maintained. The supplement states that the runway should be visually inspected for condition before use. A surface observation weather report taken at Seldovia Airport at 1619, or approximately 11 minutes before the accident, indicates the wind was calm and the visibility was 6 statute miles with light rain and mist. Aceiling of broken clouds existed at 2,500 feet and overcast clouds existed at 3,100 feet. The temperature and dew point were both reported as 01 degrees Celsius. The altimeter setting was 28.69 inches of Mercury. The Seldovia Airport is located approximately 9 nautical miles and 028 degrees magnetic from the accident airport.

Aircraft

Registration
N734JM
Reported as
Cessna U206G
Category
Airplane
Serial number
U20604839
Airframe hours
15,676
Engine
Cont Motor IO 520 SERIES, 285 horsepower, reciprocating
Damage
Substantial damage
Flight
Part 135
Operator
Smokey Bay Air Inc
Registered owner
Smokey Bay Air Inc
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · March 3, 2010
Departed
PAHO · Homer, AK
Destination
KEB · Nanwalek, AK
Flight plan
Company VFR
Airport
KEB · Nanwalek Airport, runway 01, 850 × 50 ft, gravel

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
29
Injuries
None
Certificates
Commercial, Airline transport, Flight instructor
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
November 5, 2009
Seat
Left
Flight hours
5,000 total · 1,500 in this make and model · 4,800 as pilot in command · 150 in the last 90 days · 50 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
6 statute miles
Lowest ceiling
2,500 ft broken
Temperature
34 °F, dew point 34 °F
Altimeter
28.69 inHg
Observed at
PASO, 9 nm away

Docket · 3

The files NTSB released with the investigation on February 22, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 633 KB 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.