# NTSB ANC09LA038: Cessna TU206, N629SP, Bethel, AK, May 6, 2009

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 6, 2009, 09:03 local (17:03 UTC)
- Place: Bethel, AK
- Coordinates: 60.774444, -161.840835 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=60.7744&lon=-161.8408&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Defining event: [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report July 22, 2010
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- Parties: FAA Anchorage FSDO
- NTSB case key (mKey): 73787
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC09LA038
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73787/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73787
- Page: https://openairdocs.org/ntsb/ANC09LA038

## Probable cause

The pilot’s failure to remove visible frost from the wings during the preflight inspection, and his failure to maintain adequate airspeed to avoid a stall. Contributing to the accident were conditions conducive to structural icing/frost.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=2073353), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=2073353), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Temp/humidity/pressure: conducive to structural icing](https://openairdocs.org/ntsb-findings/03031025): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-findings/03031025/cases.md?model=2073353), [All aircraft, 103 cases](https://openairdocs.org/ntsb-findings/03031025/cases.md)
- [Loading](https://openairdocs.org/ntsb-findings/01011500): Aircraft › Aircraft handling/service · Incorrect use/operation; cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-findings/01011500/cases.md?model=2073353), [All aircraft, 35 cases](https://openairdocs.org/ntsb-findings/01011500/cases.md)
- [Personality/attitude: complacency](https://openairdocs.org/ntsb-findings/02021020): Personnel issues › Psychological · Pilot; cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-findings/02021020/cases.md?model=2073353), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/02021020/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Prior to flight: Structural icing](https://openairdocs.org/ntsb-events/210); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-events/210/sequence.md?model=2073353), [All aircraft, 102 cases](https://openairdocs.org/ntsb-events/210/sequence.md)
- [Prior to flight: Aircraft loading event](https://openairdocs.org/ntsb-events/010); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-events/010/sequence.md?model=2073353), [All aircraft, 84 cases](https://openairdocs.org/ntsb-events/010/sequence.md)
- [Prior to flight: Aircraft inspection event](https://openairdocs.org/ntsb-events/050); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-events/050/sequence.md?model=2073353), [All aircraft, 229 cases](https://openairdocs.org/ntsb-events/050/sequence.md)
- [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Cessna TU206F, 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2073353), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna TU206F, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073353), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Post-impact: Cabin safety event](https://openairdocs.org/ntsb-events/110); cases with it: [Cessna TU206F, 1 case](https://openairdocs.org/ntsb-events/110/sequence.md?model=2073353), [All aircraft, 151 cases](https://openairdocs.org/ntsb-events/110/sequence.md)

## Analysis

The airplane was taking off on the first flight of the day and had accelerated normally during the short field takeoff roll. During entry into the initial climb, the airplane suddenly rolled into an uncommanded left bank and entered an uncontrolled descent. The left wingtip struck terrain to the left of the runway approximately 1,000 feet from the beginning of the takeoff roll. The airplane came to rest upright approximately 200 feet from the initial impact point. During the impact sequence the unsecured cargo shifted forward and struck the back of the pilot’s seat and the right side of the instrument panel. The pilot exited the airplane unassisted. Photos taken 5 minutes after the accident show the leading edges and tops of the wings, and horizontal tail surfaces were covered in rough frost. The photos also show the frost appears to have been scraped off of most of the windshield. There was substantial damage to the left wing, nose gear, firewall, forward empennage, and both wingtips.

## Factual narrative

On May 6, 2009, at 0903 Alaska daylight time, a single engine Cessna TU206F airplane, N629SP, sustained substantial damage when it collided with terrain during takeoff at the Bethel Airport, Bethel, Alaska. The airplane was being operated by Alaska Scenic Air LLC, Eagle River, Alaska, as a visual flight rules (VFR) on-demand cargo flight, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 135. The solo commercial pilot sustained minor injuries. Visual meteorological conditions prevailed at the airport, and company flight following procedures were in effect. The flight was en route to Kasigluk, Alaska. The airplane was taking off on the first flight of the day and had accelerated normally during the short field takeoff roll. During entry into the initial climb, the airplane suddenly rolled into an uncommanded left bank and entered an uncontrolled descent. The left wingtip struck terrain to the left of the runway approximately 1,000 feet from the beginning of the takeoff roll. The airplane came to rest upright approximately 200 feet from the initial impact point. During the impact sequence the unsecured cargo shifted forward and struck the back of the pilot’s seat and the right side of the instrument panel. The pilot exited the airplane unassisted. Photos taken 5 minutes after the accident show the leading edges and tops of the wings, and horizontal tail surfaces were covered in rough frost. The photos also show the frost appears to have been scraped off of most of the windshield. An FAA inspector, who responded to the scene, said the nose gear collapsed and there was structural damage to the firewall, forward empennage, and both wingtips. The left wing had a significant buckle at wing station 100, causing the outboard leading edge skin to open up and the inboard inner spar skin to buckle downward. At 0853, an aviation routine weather report (METAR) at Bethel, Alaska, reported wind from 330 degrees at 8 knots, 10 miles visibility, few clouds at 700 feet, temperature 27 degrees, dew point 23 degrees, and an altimeter setting of 29.93 inches of Mercury.

## Aircraft

- Registration: [N629SP](https://openairdocs.org/deregistered/N629SP-2021-07-31), registration cancelled 2021-07-31, S/N U20602070 (OpenAirDocs)
- Reported make and model: CESSNA TU206 (F)
- Registry model: [Cessna TU206F](https://openairdocs.org/model/cessna-tu206f) (registry code 2073353) (OpenAirDocs)
- Registry engine: [Continental IO-520-F](https://openairdocs.org/engine/continental-io-520-f) (registry code 17237, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: U20602070
- Airframe hours: 3092
- Engines: CONTINENTAL IO520 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: Alaska Scenic Air LLC
- Registered owner: Cessna 206 LLC
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 3, 2009, 35 hours before
- Departed: PABE, Bethel, AK
- Destination: PFKA, Kasigluk, AK
- Flight plan: Company VFR
- Airport: PABE, Bethel Airport, runway 29, 1,860 × 75 ft, gravel

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 71; injuries: minor; commercial; airplane ratings: single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 8, 2009; seat: left; flight hours: 8,089 total, 438 in this make and model, 8,089 as pilot in command, 52 in the last 90 days, 30 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 8 knots
- Visibility: 10 statute miles
- Temperature: 27 °F, dew point 23 °F
- Altimeter: 29.93 inHg
- Observed at: PABE, 1 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 20090506025169A](https://openairdocs.org/incident/20090506025169A), May 6, 2009: Cessna TU206F, Bethel, AK, Substantial damage. According to pilot's statement, after take off the aircraft's left wing began to stall probably due to the pilot using soft field take off technique and this…

## Docket (12 files)

The files NTSB released with the investigation on June 14, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73787.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 504 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329585&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Cargo Manifest - A6BC listed as Osprey Air (item 2, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329504&FileExtension=.PDF&FileName=Cargo%20Manifest%20-%20A6BC%20listed%20as%20Osprey%20Air-Redacted.PDF
- Map 1 - Airport Diagram (item 3, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329478&FileExtension=.PDF&FileName=Map%201%20-%20Airport%20Diagram-Master.PDF
- Map 2 - Runway 29 - Bethel Airport (item 4, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329492&FileExtension=.PDF&FileName=Map%202%20-%20Runway%2029%20-%20Bethel%20Airport-Master.PDF
- Map 3 - FAA Sketch of Accident Scene (item 5, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329493&FileExtension=.PDF&FileName=Map%203%20-%20FAA%20Sketch%20of%20Accident%20Scene-Master.PDF
- Weather Reports and Records (item 6, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329503&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records-Redacted.PDF
- Accident Report from Alaska State Troopers (item 7, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329501&FileExtension=.PDF&FileName=Accident%20Report%20from%20Alaska%20State%20Troopers-Redacted.PDF
- Photo 1 - Showing Damage to Forward Empennage and Left Wing (item 8, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329480&FileExtension=.PDF&FileName=Photo%201%20-%20Showing%20Damage%20to%20Forward%20Empennage%20and%20Left%20Wing-Master.PDF
- Photo 2 - Showing Frost on Wing and Horizontal Stabilizer (item 9, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329481&FileExtension=.PDF&FileName=Photo%202%20-%20Showing%20Frost%20on%20Wing%20and%20Horizontal%20Stabilizer-Master.PDF
- Photo 3 - Showing Frost on Wing (item 10, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329520&FileExtension=.PDF&FileName=Photo%203%20-%20Showing%20Frost%20on%20Wing-Master.PDF
- Photo 4 - Showing Damage to Left Wing (item 11, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329482&FileExtension=.PDF&FileName=Photo%204%20-%20Showing%20Damage%20to%20Left%20Wing-Master.PDF
- Photo 5 - Showing Unsecurred Cargo (item 12, .PDF): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40329483&FileExtension=.PDF&FileName=Photo%205%20-%20Showing%20Unsecurred%20Cargo-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.