# NTSB CEN10IA453: Piper PA-32R-301T, N4184X, Mount Pleasant, TX, August 1, 2010 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: August 1, 2010, 12:00 local (17:00 UTC) - Place: Mount Pleasant, TX - Coordinates: 33.160282, -94.970863 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.1603&lon=-94.9709&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 28, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 76815 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10IA453 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76815/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76815 - Page: https://openairdocs.org/ntsb/CEN10IA453 ## Probable cause The failure of an aileron control cable due to a seized idler pulley bearing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system: aileron control system](https://openairdocs.org/ntsb-findings/01022710): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA-32R-301T, 1 case](https://openairdocs.org/ntsb-findings/01022710/cases.md?model=7103220), [All aircraft, 45 cases](https://openairdocs.org/ntsb-findings/01022710/cases.md) - [Flight control system: aileron control system](https://openairdocs.org/ntsb-findings/01022710): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Piper PA-32R-301T, 1 case](https://openairdocs.org/ntsb-findings/01022710/cases.md?model=7103220), [All aircraft, 45 cases](https://openairdocs.org/ntsb-findings/01022710/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Piper PA-32R-301T, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=7103220), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Enroute: Inflight upset](https://openairdocs.org/ntsb-events/271); cases with it: [Piper PA-32R-301T, 1 case](https://openairdocs.org/ntsb-events/271/sequence.md?model=7103220), [All aircraft, 74 cases](https://openairdocs.org/ntsb-events/271/sequence.md) ## Analysis The pilot reported that he was in level flight with the autopilot engaged when the airplane began an uncommanded roll. The pilot disengaged the autopilot and found that the airplane’s ailerons were inoperative. The pilot made a successful landing using the rudder for directional and roll control. A postaccident examination of the airplane revealed that the right aileron primary control cable was severed where it contacted an idler pulley. That pulley would not rotate due to an out-of-tolerance idler pulley outer bearing that restricted the rotation of the pulley. It is likely that the control cable sliding against the seized pulley caused the cable to wear through. The airplane manufacturer issued a maintenance alert following this incident that highlighted the importance of proper and recurring inspections of the flight control cables and pulleys. ## Factual narrative On August 1, 2010, about 1200 central daylight time, a Piper PA-32R-301T airplane, N4184X, experienced a total loss of aileron control prior to landing at the Mount Pleasant Municipal Airport (OSA), Mount Pleasant, Texas. The airplane was not damaged and the commercial pilot was not injured. The positioning flight originated at Gilmer Municipal Airport (JXI), Gilmer, Texas, with OSA as the intended destination. The flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the incident. The pilot reported he was level at 2,000 feet mean sea level, about 10 miles from OSA, when the airplane started an un-commanded left roll. He disengaged the autopilot and discovered the ailerons were not responding. The pilot landed successfully at OSA using the rudder to control the airplane. The airplane aileron control system included two control cables routed to each wing; the primary cable and the balance cable. A postaccident examination by the operator revealed the right wing (RW) primary cable was completely severed 13 inches from the threaded end of the cable, roughly located adjacent to an idler pulley. The pulley could not be rotated when manipulated. Additional wear spots, indicated by polishing and/or fraying were annotated at additional locations on the RW primary cable, the RW balance cable, and left wing (LW) primary and balance cables. The RW primary cable had a dark grease like material covering the failure area. A similar substance was found on the idler pulley. An additional idler pulley for the RW balance cable was found that initially did not rotate when manipulated. The person manipulating the idler pulley twisted it firmly and heard a “click.” The pulley turned freely following the click. Inspectors from the Federal Aviation Administration examined the airplane and components on August 5, 2010. They stated the idler pulley at the location of the cable failure appeared to have a manufacturing flaw, in that it was not machined completely through, which created a “lip” that did not allow the bushing to go completely through the idler pulley. The suspect RW primary cable idler pulley and portions of the broken RW primary cable were sent to the manufacturer for examination. The inside diameter of the idler pulley outer bearing was found to measure .0065 inches less than the service limit for the component. The submitted portion of the primary cable was found to be manufactured from galvanized steel. Piper Aircraft, Inc. issued Service Letter No. 1135 as a maintenance alert on October 19, 2010. The alert emphasized the critical nature of control cable and pulley inspections, and highlighted the recurring inspection requirements. It included instructions for inspections of control cables and pulleys. ## Aircraft - Registration: [N4184X](https://openairdocs.org/aircraft/N4184X), registered now, S/N 3257200, built 2001 (OpenAirDocs) - Reported make and model: PIPER PA-32R-301T - Registry model: [Piper PA-32R-301T](https://openairdocs.org/model/piper-pa-32r-301t) (registry code 7103220) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 3257200 - Airframe hours: 2795 - Engines: LYCOMING TI0-540 SER 310 horsepower reciprocating - Damage: No damage - Flight: Positioning, Part 91 - Operator: South Central Logistics LLC - Registered owner: South Central Logistics LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 25, 2009 - Departed: JXI, Gilmer, TX - Destination: OSA, Mount Pleasant, TX - Flight plan: VFR - Airport: OSA, Mt Pleasant Regional Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 23; injuries: none; commercial, private; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2; last flight review November 12, 2009; seat: left; flight hours: 644 total, 36 in this make and model, 539 as pilot in command, 99 in the last 90 days, 32 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Temperature: 100 °F, dew point 64 °F - Altimeter: 29.87 inHg - Observed at: OSA, 10 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). - [Incident 20100801050189I](https://openairdocs.org/incident/20100801050189I), Aug 1, 2010: Piper PA-32R-301T, Mount Pleasant, TX, No damage. On August 1, 2010, the pilot of a Piper PA-32R-301T aircraft, N4184X, reported an incident to the national transportation and safety board (NTSB) that the… ## Docket (3 files) The files NTSB released with the investigation on May 22, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76815. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 528 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40367591&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Piper Service Letter 1135 (item 2, .PDF, 409 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40367613&FileExtension=.PDF&FileName=Piper%20Service%20Letter%201135-Master.PDF - FAA Inspector Statements (item 3, .PDF, 217 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40367626&FileExtension=.PDF&FileName=FAA%20Inspector%20Statements-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.