# NTSB ANC10LA021: Cessna U206G, N734JM, Nanwalek, AK, March 5, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 5, 2010, 16:30 local (20:30 UTC) - Place: Nanwalek, AK - Coordinates: 59.353332, -151.930557 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=59.3533&lon=-151.9306&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 28, 2011 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA/FSDO - NTSB case key (mKey): 75469 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC10LA021 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75469/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75469 - Page: https://openairdocs.org/ntsb/ANC10LA021 ## 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 NTSB's coded findings; those marked are part of the probable cause. - [Aircraft capability: landing distance](https://openairdocs.org/ntsb-findings/01061030): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [Cessna U206G, 1 case](https://openairdocs.org/ntsb-findings/01061030/cases.md?model=2073356), [All aircraft, 68 cases](https://openairdocs.org/ntsb-findings/01061030/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna U206G, 15 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2073356), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Runway/land/takeoff/taxi surface: snow/slush/ice covered surface](https://openairdocs.org/ntsb-findings/03023015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna U206G, 4 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md?model=2073356), [All aircraft, 219 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300) (defining event); cases with it: [Cessna U206G, 4 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2073356), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## 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](https://openairdocs.org/deregistered/N734JM-2013-07-26), registration cancelled 2013-07-26, S/N U20604839, built 1979 (OpenAirDocs) - Reported make and model: CESSNA U206G - Registry model: [Cessna U206G](https://openairdocs.org/model/cessna-u206g) (registry code 2073356) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: U20604839 - Airframe hours: 15676 - Engines: 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 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; injuries: none; 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 ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20100305028979A](https://openairdocs.org/incident/20100305028979A), Mar 5, 2010: Cessna U206G, Nanwalek, AK, Substantial damage. Airman was approaching to land on runway O1 to the north. Pilot stated that his base leg to final was normal. On final approach, pilot stated the aircraft… ## Docket (3 files) The files NTSB released with the investigation on February 22, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75469. 633 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 595 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327086&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Reports and Records (item 2, .PDF, 11 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40340766&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Master.PDF - Nanwalek Airport Master Record (item 3, .PDF, 27 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341204&FileExtension=.PDF&FileName=Nanwalek%20Airport%20Master%20Record-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.