# NTSB WPR11LA074: Piper PA-28-140, N5800U, Chino, CA, December 10, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 10, 2010, 15:58 local (23:58 UTC) - Place: Chino, CA - Coordinates: 33.974723, -117.63639 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.9747&lon=-117.6364&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-from runway: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 26, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 77980 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA074 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77980/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77980 - Page: https://openairdocs.org/ntsb/WPR11LA074 ## Probable cause Fatigue cracking of the upper torque-link attach lugs on the left main landing gear strut, which resulted in separation of the left main landing gear during taxi. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Piper PA-28-140, 1 case](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=7102802), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md) - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA-28-140, 1 case](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=7102802), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md) - [Maintenance/inspections: unscheduled maint checks](https://openairdocs.org/ntsb-findings/01010550): Aircraft › Aircraft handling/service · Not inspected; cases with it: [Piper PA-28-140, 1 case](https://openairdocs.org/ntsb-findings/01010550/cases.md?model=7102802), [All aircraft, 6 cases](https://openairdocs.org/ntsb-findings/01010550/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi-from runway: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Piper PA-28-140, 7 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7102802), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The certified flight instructor and student pilot had just performed a soft-field landing. During the subsequent rollout, they noted that the airplane was not taxiing as expected. As the airplane exited the runway, it dropped onto its left wing and spun to the left. Examination of the left main landing gear revealed that the upper torque-link attachment lugs had detached from the landing gear strut, causing separation of the wheel assembly and subsequent substantial damage to the left wing. Further metallurgical examination of the strut revealed evidence of preexisting fatigue cracks to the upper torque-link attachment lugs. The airplane manufacturer issued a Service Bulletin about 8 years prior to the accident requiring inspection of the lugs in the area of failure. No evidence was found suggesting that the Service Bulletin had been complied with. ## Factual narrative On December 10, 2010, at 1558 Pacific standard time, a Piper PA-28-140, N5800U, sustained substantial damage to the left wing during taxi after landing at Chino Airport, Chino, California. DuBois Aviation operated the airplane under the provisions of Title 14 Code of Federal Regulations Part 91 as an instructional flight. The student pilot and certificated flight instructor (CFI) were not injured. The local instructional flight departed Chino about 1430. Visual meteorological conditions prevailed, and no flight plan had been filed. The CFI reported that after performing a soft-field landing, the airplane was not taxing as expected. As they exited the runway, the airplane dropped onto its left wing, and spun to the left. Examination of the left main landing gear strut (part number 65319-3) by the NTSB investigator-in-charge revealed that the upper torque-link attachment lugs had detached from the landing gear strut. Additionally, the wheel assembly had become separated from the strut, coming to rest against the aft underside surface of the wing. The wing sustained wrinkles to the upper and lower inboard skins, and three collapsed wing ribs were observed. Both the CFI and the student pilot reported performing an uneventful preflight inspection prior to the accident flight, noting no preexisting structural damage to the airplane. The landing gear strut and lugs were sent to the NTSB Materials Laboratory for further examination. Metallurgical examination revealed that both lug separation surfaces exhibited curving boundary features, and areas of discoloration indicative of preexisting cracks. New Piper Aircraft, Inc., issued Service Bulletin (SB) 1131 on August 18, 2003, requiring visual and dye penetrant inspections of "cast" main landing gear strut cylinders at the next regularly scheduled maintenance event (or within 100 hours), and at 100-hour intervals thereafter until the cylinder was replaced with a new forged part. The subject cylinder was of the "cast" type, with a serial number that was found to be within the SB's affected range. Examination of the airplane's maintenance logbooks revealed that this Service Bulletin had not been performed. ## Aircraft - Registration: [N5800U](https://openairdocs.org/deregistered/N5800U-2020-05-26), registration cancelled 2020-05-26, S/N 28-23502, built 1967 (OpenAirDocs) - Reported make and model: PIPER PA-28-140 - Registry model: [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140) (registry code 7102802) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-23502 - Airframe hours: 7350 - Engines: LYCOMING O-320 SERIES 150 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Dubois Aviation Inc - Registered owner: Dubois Aviation Inc - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: 100 hour, November 20, 2010, 63 hours before - Departed: CNO, Chino, CA - Destination: CNO, Chino, CA - Airport: CNO, Chino, runway 26L, 7,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 27; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 16, 2010; seat: right; flight hours: 1,235 total, 692 in this make and model, 1,188 as pilot in command, 135 in the last 90 days, 39 in the last 30 days, 2 in the last 24 hours - Student pilot; age 46; injuries: none; student; medical: without waivers/limitations; seat: left; flight hours: 63 total, 61 in this make and model, 13 as pilot in command, 17 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 5 knots - Visibility: 5 statute miles - Lowest ceiling: 20,000 ft broken - Temperature: 68 °F, dew point 52 °F - Altimeter: 30.05 inHg - Observed at: CNO, 5 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). - [Accident 20101210055049A](https://openairdocs.org/incident/20101210055049A), Dec 10, 2010: Piper PA-28-140, Chino, CA, Substantial damage. On dec 10 2010, a Piper PA-28-140 landed at Chino Airport on runway 26LEFT and at approximately 15:54 PST was taxiing and acccording to the written statement… ## Other investigations on N5800U (1) 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. - [NTSB GAA19CA095](https://openairdocs.org/ntsb/GAA19CA095), Dec 12, 2018: Piper PA28 (N5800U), Chino, CA, substantial damage. Probable cause: The flight instructor's failure to maintain directional control during landing. ## Docket (7 files) The files NTSB released with the investigation on March 24, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77980. 5.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 701 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344635&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Laboratory 15 - Factual Report 11-004 (item 2, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344530&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2011-004-Master.PDF - Piper Aircraft Service Bulletin 1311 (item 3, .PDF, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344535&FileExtension=.PDF&FileName=Piper%20Aircraft%20Service%20Bulletin%201311-Master.PDF - Airframe Logbook Excerpts (item 4, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344536&FileExtension=.PDF&FileName=Airframe%20Logbook%20Excerpts-Redacted.PDF - Evidence Control (item 5, .PDF, 197 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344604&FileExtension=.PDF&FileName=Evidence%20Control-Master.PDF - Photo 1. Left Wing Skin Damage (FAA Photograph) (item 6, .PDF, 159 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344537&FileExtension=.PDF&FileName=Photo%201.%20%20Left%20Wing%20Skin%20Damage%20(FAA%20Photograph)-Master.PDF - Photo 2. Left Strut Damage (FAA Photograph) (item 7, .PDF, 237 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344538&FileExtension=.PDF&FileName=Photo%202.%20%20Left%20Strut%20Damage%20(FAA%20Photograph)-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.