# NTSB ERA13IA267: Piper PA-34-200T, N633TC, Tallahassee, FL, June 3, 2013 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: June 3, 2013, 15:20 local (19:20 UTC) - Place: Tallahassee, FL - Coordinates: 30.396944, -84.35083 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.3969&lon=-84.3508&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 27, 2015 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - ADs cited in the narratives: [AD 2013-02-13](https://openairdocs.org/ad/2013-02-13) (OpenAirDocs) - NTSB case key (mKey): 87084 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA13IA267 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87084/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87084 - Page: https://openairdocs.org/ntsb/ERA13IA267 ## Probable cause The failure of the elevator trim cable due to fatigue cracking, which resulted from maintenance personnel’s repeated inadequate inspection of the cable. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system: elevator tab control system](https://openairdocs.org/ntsb-findings/01022731): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA-34-200T, 2 cases](https://openairdocs.org/ntsb-findings/01022731/cases.md?model=7103406), [All aircraft, 37 cases](https://openairdocs.org/ntsb-findings/01022731/cases.md) - [Inspection: scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-34-200T, 1 case](https://openairdocs.org/ntsb-findings/02061520/cases.md?model=7103406), [All aircraft, 167 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md) - [Maintenance/inspections: scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520): Aircraft › Aircraft handling/service · Inadequate inspection (probable cause); cases with it: [Piper PA-34-200T, 1 case](https://openairdocs.org/ntsb-findings/01010520/cases.md?model=7103406), [All aircraft, 76 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Piper PA-34-200T, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=7103406), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Emergency descent: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333); cases with it: [Piper PA-34-200T, 1 case](https://openairdocs.org/ntsb-events/333/sequence.md?model=7103406), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) ## Analysis According to the flight instructor, during the initial climb, the student pilot noticed a problem with the elevator trim wheel. The flight instructor moved the trim wheel and noted no resistance. He then looked down at the wheel and observed the trim cable protruding from its side. The flight instructor assumed control of the airplane, advised the tower air traffic controller of the emergency, and landed the airplane without incident. Examination of the elevator trim cable assembly revealed that the trim cable failed due to fatigue cracking of the individual wires. The wire breaks were so numerous and over such a sizable length that they should have been detectable by a visual inspection. However, a review of the aircraft logbooks revealed that maintenance personnel did not detect the fatigue cracking of the wires during the most recent 100-hour and annual inspections nor during compliance with an airworthiness directive (AD) that required, in part, that all control cables be inspected for broken wires strands and that any broken wire strands be replaced; the inspections and AD were accomplished less than 2 months before the incident. ## Factual narrative On June 3, 2013, about 1520 eastern daylight time, a Piper PA-34-200T, N633TC, experienced a trim cable failure during climbout from Tallahassee Regional Airport (TLH), Tallahassee, Florida. The flight instructor (CFI) and student pilot were not injured, and the airplane was not damaged. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was registered to and operated by Florida Flight Training Center under the provisions of Title 14 Code of Federal Regulations Part 91 as an instructional flight. The flight was originating at the time of the incident. The CFI stated they departed from TLH uneventfully and were climbing through 300 feet when the student pilot noticed a problem with the elevator trim wheel. The CFI moved the trim wheel and noted no resistance when the wheel was turned. Upon looking down at the wheel, he observed the trim cable protruding out from the side of the wheel. The student pilot advised that he was having difficulty controlling the airplane and the CFI subsequently assumed control of the airplane. The CFI advised the tower controller of the emergency and landed the airplane without incident. Examination of the airplane revealed that the elevator trim cable had broken and was protruding from the trim wheel housing. The elevator trim cable assembly was sent to the NTSB material laboratory for examination. An examination of the trim cable revealed that it was composed of a 1/16 inch diameter wire rope with a swaged-on ball at one end and a swaged-on turnbuckle fitting at the other end. Visual inspection revealed trim cable lubrication along the entire length with no indication of external corrosion. The wire rope section had separated about 5 feet 6 inches from the turnbuckle end and 14 feet 6 inches from the ball end of the cable. The separation was made up of individual wire breaks spread along an approximate 2-inch length of the wire rope. A magnified visual inspection of the cleaned cable established that all but a few wires were fractured directly across the wires with no apparent yielding or deformation. Further, only a few wires (broken or intact) showed either internal or external wear. A scanning electron microscope examination of several of the broken wires revealed features consistent with fatigue progression through the individual wires. A review of the aircraft logbooks revealed that the failure of the trim cable was not detected on April 25, 2013, -during the 100 hour and annual inspections. Nor was it noted on April 13, 2013, during the compliance of AD 2013-02-13; which states in section 7-149 a) "At each annual or 100 hour inspection, all control cables must be inspected for broken wires strands. Any cable assembly that has one broken wire strand located in a critical fatigue area must be replaced." The inspection was completed 3 months prior to this event. ## Aircraft - Registration: [N633TC](https://openairdocs.org/aircraft/N633TC), registered now, S/N 34-7870328, built 1978 (OpenAirDocs) - Reported make and model: PIPER PA-34-200T - Registry model: [Piper PA-34-200T](https://openairdocs.org/model/piper-pa-34-200t) (registry code 7103406) (OpenAirDocs) - Registry engine: [Continental TSIO-360 series](https://openairdocs.org/engine/continental-tsio-360-series) (registry code 17019, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 34-7870328 - Airframe hours: 7424 - Engines: CONT MOTOR TSIO-360 SER 225 horsepower reciprocating; CONT MOTOR TSIO-360 SER 225 horsepower reciprocating - Damage: No damage - Flight: Instructional, Part 91 - Operator: Florida Flight Training Center - Registered owner: Hawkins Alan - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 25, 2013, 117 hours before - Departed: TLH, Tallahassee, FL - Destination: VNC, Venice, FL - Airport: TLH, Tallahassee, runway 09, 8,003 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 27; injuries: none; flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 12, 2012; seat: right; flight hours: 1,500 total, 500 in this make and model, 1,200 as pilot in command, 100 in the last 90 days, 40 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 10 knots, gusting 14 - Visibility: 10 statute miles - Lowest ceiling: 6,000 ft broken - Temperature: 90 °F, dew point 70 °F - Altimeter: 29.88 inHg - Observed at: TLH ## Docket (12 files) The files NTSB released with the investigation on March 30, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87084. 4.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 587 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40394651&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - CFI Statement Trim Tab Malfunction (item 2, .PDF, 24 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424107&FileExtension=.PDF&FileName=CFI%20Statement%20Trim%20Tab%20Malfunction-Redacted.PDF - Aircraft Logbook Annual excerpt page (item 3, .PDF, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424108&FileExtension=.PDF&FileName=Aircraft%20Logbook%20Annual%20excerpt%20page-Redacted.PDF - N633TC Stabilator Cable Replacement Log excerpt (item 4, .PDF, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424109&FileExtension=.PDF&FileName=N633TC%20Stabilator%20Cable%20Replacement%20Log%20excerpt-Redacted.PDF - Stabilator Inspection AD Sign Off (item 5, .PDF, 34 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424110&FileExtension=.PDF&FileName=Stabilator%20Inspection%20AD%20Sign%20Off-Redacted.PDF - Stabilator Control System Inspection Service Bulletin 1245A (item 6, .PDF, 168 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424111&FileExtension=.PDF&FileName=Stabilator%20Control%20System%20Inspection%20Service%20Bulletin%201245A-Master.PDF - FAA Advisory Circular 43.13-1B excerpt (item 7, .PDF, 96 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424112&FileExtension=.PDF&FileName=FAA%20Advisory%20Circular%2043.13-1B%20excerpt-Master.PDF - Trim Cable Airworthiness Directive 2013-02-13 (item 8, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424113&FileExtension=.PDF&FileName=Trim%20Cable%20Airworthiness%20Directive%202013-02-13-Master.PDF - Materials Laboratory Factual report 14-048 (item 9, .PDF, 5 photos, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424114&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20report%2014-048-Master.PDF - Piper Seneca II Service Diagram (item 10, .PDF, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424115&FileExtension=.PDF&FileName=Piper%20Seneca%20II%20Service%20Diagram-Master.PDF - Photo 1 - Broken Cable (Photo Courtesy of FAA) (item 11, .PDF, 776 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424116&FileExtension=.PDF&FileName=Photo%201%20-%20Broken%20Cable%20(Photo%20Courtesy%20of%20FAA)-Master.PDF - Photo 2 - Baggage Compartment (Photo Courtesy of FAA) (item 12, .PDF, 612 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40424117&FileExtension=.PDF&FileName=Photo%202%20-%20Baggage%20Compartment%20(Photo%20Courtesy%20of%20FAA)-Master.PDF From the NTSB's public API. 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