# NTSB CEN11IA108: Piaggio P180, N140SL, Columbus, OH, December 13, 2010 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: December 13, 2010, 08:30 local (13:30 UTC) - Place: Columbus, OH - Coordinates: 39.998054, -82.891944 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.9981&lon=-82.8919&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report March 20, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration, ANSV, Avantair Inc. - ADs cited in the narratives: [AD 2011-01-53](https://openairdocs.org/ad/2011-01-53), [AD 2011-01-51](https://openairdocs.org/ad/2011-01-51) (OpenAirDocs) - NTSB case key (mKey): 78002 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11IA108 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78002/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78002 - Page: https://openairdocs.org/ntsb/CEN11IA108 ## Probable cause The failure of water to properly drain through the fuselage drain holes, thus becoming trapped and freezing around the flight control cables, which resulted in the loss of control authority to the airplane's ailerons, elevator, and rudder. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuselage: fuselage main structure](https://openairdocs.org/ntsb-findings/01035310): Aircraft › Aircraft structures · Malfunction (probable cause); cases with it: [All aircraft, 24 cases](https://openairdocs.org/ntsb-findings/01035310/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible; cases with it: [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Temp/humidity/pressure: low temperature](https://openairdocs.org/ntsb-findings/03031010): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [All aircraft, 8 cases](https://openairdocs.org/ntsb-findings/03031010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) ## Analysis During the airplane's descent, the yaw damper disengaged while the autopilot remained on. When the flightcrew checked the flight controls for freedom of control, the ailerons, elevator, and rudder were found to be frozen in place. The flightcrew exerted enough pressure until the controls broke free with a “snap.” The flight controls remained stiff for the remainder of the flight. The temperature was -9 degrees C at the destination. Following a normal approach and landing, the flight controls and nosewheel steering became inoperative. The flightcrew used differential power and braking to taxi to the ramp. A postflight examination by maintenance personnel revealed ice in the area of frame 36 and around the primary flight control cables and pulleys in that area. An examination of the fuselage drain holes showed no obstructions and the airplane was returned to service. An emergency airworthiness directive was subsequently issued that advised of three incidents and that required inspection of the fuselage belly and testing of the fuselage drain holes. ## Factual narrative On December 13, 2010, about 0830 eastern standard time, a Piaggio P180, N140SL, operated by Avantair Inc., sustained no damage when the airplane’s flight controls bound during approach to the Port Columbus International Airport (CMH), near Columbus, Ohio. The two pilots and two passengers were not injured. Marginal visual meteorological conditions prevailed. The flight was operating on an activated instrument flight rules flight plan. The business flight was conducted under 14 Code of Federal Regulations Part 91K. The flight departed from the Westchester County Airport (HPN), near White Plains, New York, about 0700, and was destined for CMH. According to the operator, the flight departed HPN and initially leveled off at a pressure altitude of 26,000 feet. An indicated airspeed caution light illuminated. The flighcrew performed the abnormal checklist for the number two air data computer failure and selected the number one computer to continue with for the remainder of the flight. During the descent in to CMH at about 15,000 feet the yaw damper disengaged while the autopilot remained on. The captain instructed the first officer who was the pilot flying to check the freedom of the flight controls. The first officer found the ailerons, elevator, and rudder to be "frozen" in place. The flightcrew exerted enough pressure until the controls broke free with a “snap.” The flight controls remained "stiff and sticky" for the remainder of the flight. The flightcrew performed a normal approach and landing on runway 28L. Once on the ground the flight controls and nose wheel steering became inoperative. The flightcrew used differential power and braking to taxi to the ramp. A post flight inspection by maintenance personnel revealed ice in the fuselage belly area of frame 36 and around the primary flight control cables and pulleys in that area. The ice was warmed by heaters and removed from the fuselage belly. The fuselage drain holes were inspected for obstructions and general condition. No anomalies were detected. The fuselage belly was towel dried and the airplane was returned to service. At 0851, the recorded weather at CMH was: Wind 310 degrees at 8 knots; visibility 4 statute miles; present weather light snow and mist; sky condition overcast 2,200 feet; temperature -9 degrees C; dew point -12; altimeter 29.73 inches of mercury. On December 20, 2010, the Federal Aviation Administration issued emergency airworthiness directive (AD) 2011-01-53 to all known U.S. owners/operators of Piaggio P180s. The AD, in part, stated: Unsafe Condition ... (e) This emergency AD was prompted by three incidents of the flight controls jamming on Piaggio Model P-180 airplanes. Water or fluid accumulating and freezing when the aircraft reaches and holds altitudes where the temperature is below the freezing point may cause the flight controls to jam with consequent loss of control. ... Inspection and Corrective Actions (g) Unless already done in compliance with emergency AD2011-01-51, before further flight, do the following actions using the instructions in Appendix 1 of this AD. (1) Remove the central floor panels in the cabin and inspect the fuselage belly; and (2) Functional test the fuselage drain holes. ## Aircraft - Registration: N140SL (not matched to a registry record) - Reported make and model: PIAGGIO P180 - Category: Airplane - Serial number: 1107 - Airframe hours: 5006 - Engines: P&W CANADA PT6A-66 850 horsepower turbo prop; P&W CANADA PT6A-66 850 horsepower turbo prop - Damage: No damage - Flight: Part 91 subpart K - Operator: Avantair, Inc. - Registered owner: Aviation Services LLC - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, November 5, 2010 - Departed: HPN, White Plains, NY - Destination: CMH, Columbus, OH - Flight plan: IFR - Airport: CMH, Port Columbus IAP, runway 28L, 10,125 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review December 7, 2010; seat: left; flight hours: 7,000 total, 2,700 in this make and model, 6,500 as pilot in command, 120 in the last 90 days, 50 in the last 30 days, 7 in the last 24 hours - Co-pilot; age 33; injuries: none; airline transport, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review July 3, 2010; seat: right; flight hours: 5,500 total, 500 in this make and model, 4,400 as pilot in command, 120 in the last 90 days, 50 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 8 knots - Visibility: 4 statute miles - Lowest ceiling: 2,200 ft overcast - Temperature: 16 °F, dew point 10 °F - Altimeter: 29.72 inHg - Observed at: CMH ## Docket (7 files) The files NTSB released with the investigation on February 3, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78002. 3.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348886&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Flightcrew Statement (item 2, .PDF, 42 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358592&FileExtension=.PDF&FileName=Flightcrew%20Statement-Redacted.PDF - Photo - View of accumulated ice under the floorboards (item 3, .PDF, 210 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40359990&FileExtension=.PDF&FileName=Photo%20-%20View%20of%20accumulated%20ice%20under%20the%20floorboards-Master.PDF - Photo - View of ice around flight control cables (item 4, .PDF, 1 photo, 246 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40359985&FileExtension=.PDF&FileName=Photo%20-%20View%20of%20ice%20around%20flight%20control%20cables-Master.PDF - Miscellaneous - Flight Log Excerpt (item 5, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358614&FileExtension=.PDF&FileName=Miscellaneous%20-%20Flight%20Log%20Excerpt-Redacted.PDF - Miscellaneous - Emergency Airworthiness Directive (AD) 2011-01-53 (item 6, .PDF, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358599&FileExtension=.PDF&FileName=Miscellaneous%20-%20Emergency%20Airworthiness%20Directive%20(AD)%202011-01-53-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 360 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40348887&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.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.