# NTSB WPR11LA218: Piper PA46-500TP, N46ME, Rock Springs, WY, May 3, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 3, 2011, 17:40 local (23:40 UTC) - Place: Rock Springs, WY - Coordinates: 41.594165, -109.065277 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5942&lon=-109.0653&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 28, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration, Piper Aircraft Company, Piper Aircraft - NTSB case key (mKey): 79023 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA218 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/79023/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=79023 - Page: https://openairdocs.org/ntsb/WPR11LA218 ## Probable cause The overstress fracture of the right aileron midspan hinge bracket due to modal vibrations created by a deflated right main landing gear tire during the takeoff roll. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wing structure: ailerons](https://openairdocs.org/ntsb-findings/01035751): Aircraft › Aircraft structures · Damaged/degraded (probable cause); cases with it: [Piper PA46-500TP, 1 case](https://openairdocs.org/ntsb-findings/01035751/cases.md?model=7104622), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01035751/cases.md) - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Not specified (probable cause); cases with it: [Piper PA46-500TP, 2 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=7104622), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md) - [Landing gear system: tire casing](https://openairdocs.org/ntsb-findings/01023244): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA46-500TP, 3 cases](https://openairdocs.org/ntsb-findings/01023244/cases.md?model=7104622), [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/01023244/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Piper PA46-500TP, 2 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7104622), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) ## Analysis During the takeoff roll, as the airplane approached 70 knots, it started slowly pulling to the right. The pilot immediately aborted the takeoff and stopped the airplane on the runway using brakes and reverse propeller thrust. The pilot inspected the airplane and found that the right main landing gear tire had blown, and the right aileron had buckled at the aileron midspan hinge location. There were no scuff marks or indentations to indicate that the hinge or area around the hinge had been struck by debris. The hinge was still attached to the aileron, but the attach bracket that connected the hinge to the wing had fractured. Metallurgical examination revealed that the failure of the hinge bracket was the result of overstress forces applied to the hinge. Overstress failure of only the midspan hinge is somewhat unusual when none of the other hinges were damaged, which suggests modal vibration forces concentrated at this particular hinge. It is likely that the flat tire could have induced the vibratory mode in the aileron at the midspan hinge. ## Factual narrative HISTORY OF FLIGHT On May 3, 2011, at 1740 mountain daylight time, the pilot of a Piper PA46-500TP, N46ME, aborted the takeoff at Rock Springs-Sweetwater County Airport, Rock Springs, Wyoming, after the right main landing gear tire failed. The airline transport pilot operated the airplane under the provisions of Title 14 Code of Federal Regulations, Part 91. The pilot was not injured, and the right aileron was substantially damaged. Visual meteorological conditions prevailed, and an IFR flight plan had been filed. The pilot reported that during the takeoff roll, as the airplane approached 70 knots, it started slowly pulling to the right. He immediately aborted the takeoff, and stopped the airplane on the runway using brakes and reverse propeller thrust. The pilot inspected the airplane and found the right main landing gear tire blown, and the right aileron buckled at the aileron center hinge location. There were no scuff marks or indentations to indicate that the hinge or area around the hinge had been struck by debris. The hinge was still attached to the aileron, but the attach bracket that connected the hinge to the wing had fractured. The operator removed the entire hinge component and associated pieces. The hinge pieces were sent to the NTSB Materials Laboratory for examination. TESTS AND RESEARCH The NTSB Materials Laboratory examination revealed that the aileron hinge attach brackets were each fractured at three places. The fractures were all located at manufactured bend locations. Optical examinations of the fracture faces revealed deformation and fracture features consistent with overstress separations. Further observation with a scanning electron microscope uncovered ductile dimples on the fracture surfaces indicating both shearing and tensile overstress forces. No indications of progressive separation or corrosion were found. Photographs of the blown tire, Goodyear Flight Special II, part number 606C81B1, serial number 8029718, were examined by a technical representative of Goodyear Aviation Tires. The technical representative’s assessment of the blown tire was that it appeared to be a typical “run-flat” condition. The distorted shape, blue rubber, and the liner appearance was consistent with that of a tire that had been run overdeflected (underinflated and/or overloaded) during use in service. The upper sidewall appears to have been cut from the adjacent areas of the tire by running between the wheel flange and runway surface due to the overdeflected condition. ADDITIONAL INFORMATION The airplane manufacturer reported that they had knowledge of a similar incident that occurred on January 20, 2010, on a different PA46. In this instance, a main tire blew, and the aileron center hinge failed in a similar fashion. Piper Aircraft’s engineering department is currently investigating the hinge and the unusual phenomena associated with the hinge failure. ## Aircraft - Registration: [N46ME](https://openairdocs.org/aircraft/N46ME), registered now, S/N 4697207, built 2005 (OpenAirDocs) - Reported make and model: PIPER PA46-500TP - Registry model: [Piper PA46-500TP](https://openairdocs.org/model/piper-pa46-500tp) (registry code 7104622) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 4697207 - Airframe hours: 472 - Engines: P&W PT6A SER 500 horsepower turbo prop - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Pope Elmore Eugene - Registered owner: Pope Elmore Eugene - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 2, 2011 - Departed: KRKS, Rock Springs, WY - Destination: KBFI, Seattle, WA - Flight plan: IFR - Airport: KRKS, Rock Springs, runway 27, 10,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: none; commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2; last flight review March 18, 2011; seat: left; flight hours: 12,150 total, 1,980 in this make and model, 11,850 as pilot in command, 145 in the last 90 days, 65 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 25 °F - Altimeter: 30.13 inHg - Observed at: KRKS ## 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 20110503008189A](https://openairdocs.org/incident/20110503008189A), May 3, 2011: Piper PA46-500TP, Rock Springs, WY, Substantial damage. On may 3, 2011 at 17:40 MDT, N46ME, a Piper model PA46-500TP sustained substantial damage during take-off roll at Rock Springs, WY (rks) airport. The sole… ## Docket (10 files) The files NTSB released with the investigation on May 10, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=79023. 4.4 MB in all. - Materials Laboratory 15 - Factual Report 02-002 (4 images) (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40363224&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2002-002%20(4%20images)-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 628 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366641&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1 - Top View of the Aileron (item 3, .PDF, 353 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366642&FileExtension=.PDF&FileName=Photo%201%20-%20Top%20View%20of%20the%20Aileron-Master.PDF - Photo 2 - Underside View of the Aileron (item 4, .PDF, 420 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366643&FileExtension=.PDF&FileName=Photo%202%20-%20Underside%20View%20of%20the%20Aileron-Master.PDF - Photo 3 - Aileron Hinge (item 5, .PDF, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366644&FileExtension=.PDF&FileName=Photo%203%20-%20Aileron%20Hinge-Master.PDF - Photo 4 - Tire (item 6, .PDF, 938 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366645&FileExtension=.PDF&FileName=Photo%204%20-%20Tire-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 7, .PDF, 97 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366646&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Aileron and Wing Part Diagrams (item 8, .PDF, 159 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366647&FileExtension=.PDF&FileName=Aileron%20and%20Wing%20Part%20Diagrams-Master.PDF - Identification of a Previous Hinge Failure (email) (item 9, .PDF, 191 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366648&FileExtension=.PDF&FileName=Identification%20of%20a%20Previous%20Hinge%20Failure%20(email)-Redacted.PDF - Goodyear Tire Consultation (item 10, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40366708&FileExtension=.PDF&FileName=Goodyear%20Tire%20Consultation-Redacted.PDF From the NTSB's public API. 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