# NTSB GAA17CA158: Socata TBM700, Bellingham, WA, February 27, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: February 27, 2017, 12:20 local (20:20 UTC) - Place: Bellingham, WA - Coordinates: 48.791942, -122.534721 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.7919&lon=-122.5347&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 10, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 94782 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA158 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94782/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94782 - Page: https://openairdocs.org/ntsb/GAA17CA158 ## Probable cause The pilot’s failure to properly deice the airplane before takeoff, which resulted in an aerodynamic stall during the initial climb. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Action: incomplete action](https://openairdocs.org/ntsb-findings/02041040): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [All aircraft, 105 cases](https://openairdocs.org/ntsb-findings/02041040/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Ceiling/visibility/precip: snow](https://openairdocs.org/ntsb-findings/03035045): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [All aircraft, 43 cases](https://openairdocs.org/ntsb-findings/03035045/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot; cases with it: [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/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: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Takeoff: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Takeoff: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, during the preflight, it was snowing, and he wiped the snow that had accumulated on the wings off "as best as [he] could." He added that, while taxiing to the runway, "snow was falling heavily," and he observed "light accumulation of wet snow" on the wings. During the takeoff roll, he observed the snow "sloughing off" the wings as the airspeed increased. Subsequently, during the climb to about 150 ft above the ground, the airplane yawed to the left, and he attempted to recover using right aileron. He reported that he "could see a stall forming," so he lowered the nose and reduced power to idle. The airplane impacted the general aviation ramp in a left-wing-down attitude and slid 500 to 600 ft. The pilot reported on the National Transportation Safety Board Aircraft Accident/ Incident Report 6120.1 form that the airplane stalled, and he recommended "better deicing" before takeoff. The airplane sustained substantial damage to the fuselage and left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. A review of recorded data from the automated weather observation station located on the airport revealed that, about 27 minutes before the accident, the wind was 010° at 8 knots, 1/2-mile visibility, moderate snow, freezing fog, and sky condition broken at 500 ft above ground level (agl) and overcast at 1,500 ft agl. The airplane departed from runway 16. The Federal Aviation Administration (FAA) Aeronautical Information Manual stated, in part: "The presence of aircraft airframe icing during takeoff, typically caused by improper or no deicing of the aircraft being accomplished prior to flight has contributed to many recent accidents in turbine aircraft." The manual further stated, "Ensure that your aircraft's lift-generating surfaces are COMPLETELY free of contamination before flight through a tactile (hands on) check of the critical surfaces when feasible. Even when otherwise permitted, operators should avoid smooth or polished frost on lift-generating surfaces as an acceptable preflight condition." FAA Advisory Circular, AC 135-17, stated in part: "Test data indicate that ice, snow, or frost formations having thickness and surface roughness similar to medium or course sandpaper on the leading edge and upper surfaces of a wing can reduce wing lift by as much as 30 percent and increase drag by 40 percent." Included in the public docket for this report is a copy of a service bulletin from the airplane manufacturer, which describes deicing and anti-icing ground procedures. It stated, in part: During conditions conducive to aeroplane icing during ground operations, take-off shall not be attempted when ice, snow, slush or frost is present or adhering to the wings, propellers, control surfaces, engine inlets or other critical surfaces. This is known as the "Clean Aircraft Concept". Any deposit of ice, snow or frost on theexternal surfaces may drastically affect its performance due to reduced aerodynamic lift and increased drag resulting from the disturbed airflow. ## Factual narrative The pilot reported that during the preflight it was snowing and he wiped the snow that had accumulated on the wings off "as best as [he] could". He added that while taxiing to the runway, "snow was falling heavily" and he observed "light accumulation of wet snow" on the wings. During the takeoff roll, he observed the snow "sloughing off" the wings as the airspeed increased. Subsequently, during the climb about 150 ft above the ground, the airplane yawed to the left, and he attempted to recover using right aileron. He reported that he "could see a stall forming" so he lowered the nose and reduced power to idle. The airplane impacted the general aviation ramp in a left wing down attitude and slid 500 to 600 ft. The pilot reported on the National Transportation Safety Board Aircraft Accident/ Incident Report 6120.1 form that the airplane stalled and he recommended "better deicing" before takeoff. The airplane sustained substantial damage to the fuselage and left wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. A review of recorded data from the automated weather observation station, located on the airport, revealed that about 27 minutes before the accident the wind was 010° at 8 knots, ½ mile visibility; moderate snow, freezing fog, sky condition broken at 500 ft above ground level (agl) and overcast at 1,500 ft agl. The airplane departed runway 16. The Federal Aviation Administration Aeronautical Information Manual (AIM) stated in part: "The presence of aircraft airframe icing during takeoff, typically caused by improper or no deicing of the aircraft being accomplished prior to flight has contributed to many recent accidents in turbine aircraft." The manual further stated: "Ensure that your aircraft's lift-generating surfaces are COMPLETELY free of contamination before flight through a tactile (hands on) check of the critical surfaces when feasible. Even when otherwise permitted, operators should avoid smooth or polished frost on lift-generating surfaces as an acceptable preflight condition." The Federal Aviation Administration Advisory Circular, AC 135-17, stated in part: "Test data indicate that ice, snow, or frost formations having thickness and surface roughness similar to medium or course sandpaper on the leading edge and upper surfaces of a wing can reduce wing lift by as much as 30 percent and increase drag by 40 percent." Included in the public docket for this report is a copy of a service bulletin from the airplane manufacturer, which describes de-icing and anti-icing ground procedures. It stated in part: "During conditions conducive to aeroplane icing during ground operations, take-off shall not be attempted when ice, snow, slush or frost is present or adhering to the wings, propellers, control surfaces, engine inlets or other critical surfaces. This is known as the "Clean Aircraft Concept". Any deposit of ice, snow or froston the external surfaces may drastically affect its performance due to reduced aerodynamic lift and increased drag resulting from the disturbed airflow." ## Aircraft - Registration: CGWVS (not matched to a registry record) - Reported make and model: SOCATA TBM700 (B) - Category: Airplane - Serial number: 210 - Year built: 2002 - Airframe hours: 1962.1 - Engines: P&W Canada PT6A-64 700 horsepower turbo prop - Damage: Substantial damage - Flight: Business, Part 91 - Operator: 4197802 Manitoba Ltd. - Registered owner: 4197802 Manitoba Ltd. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, December 15, 2016 - Departed: BLI, Bellingham, WA - Destination: PLU, PUYALLUP, WA - Flight plan: IFR - Airport: BLI, Bellingham Intl, runway 16, 6,701 × 150 ft, asphalt - Equipment: Electronic multifunction display, Auto-pilot, ADS-B, Stall warning system, Onboard weather, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review May 3, 2016; seat: left; flight hours: 1,703.4 total, 381.5 in this make and model, 1,511.9 as pilot in command ## Weather - Conditions: Instrument (IMC), Day - Wind: 10° at 8 knots - Lowest ceiling: 500 ft broken - Temperature: 30 °F, dew point 28 °F - Altimeter: 29.69 inHg - Observed at: KBLI ## Docket (3 files) The files NTSB released with the investigation on March 29, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94782. 1.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40450407&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Photo (Courtesy of FAA) (item 2, .PDF, 1 photo, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40450408&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20FAA)-Master.PDF - Daher-Socata Service Bulletin (item 3, .PDF, 143 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40450409&FileExtension=.PDF&FileName=Daher-Socata%20Service%20Bulletin-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.