# NTSB ERA14LA170: Cessna 421, N5929M, Charleston, SC, March 20, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 20, 2014, 12:05 local (16:05 UTC) - Place: Charleston, SC - Coordinates: 32.898612, -80.040275 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.8986&lon=-80.0403&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 17, 2016 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: Textron Aviation, FAA/FSDO - NTSB case key (mKey): 88966 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA14LA170 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88966/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88966 - Page: https://openairdocs.org/ntsb/ERA14LA170 ## Probable cause Inadequate maintenance, which resulted in the collapse of the right main landing gear during landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna 421B, 2 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=2076014), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Landing gear system: main landing gear attach sec](https://openairdocs.org/ntsb-findings/01023211): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-findings/01023211/cases.md?model=2076014), [All aircraft, 66 cases](https://openairdocs.org/ntsb-findings/01023211/cases.md) - [Object/animal/substance: runway/taxi/approach light](https://openairdocs.org/ntsb-findings/03022012): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-findings/03022012/cases.md?model=2076014), [All aircraft, 106 cases](https://openairdocs.org/ntsb-findings/03022012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Cessna 421B, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=2076014), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Cessna 421B, 7 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2076014), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The commercial pilot was concluding a personal flight with two passengers on board. The pilot reported that, during the landing roll and after a normal touchdown on the concrete runway, the right main landing gear (MLG) collapsed. The airplane then veered right and struck two runway lights, which resulted in substantial damage to the right wing rear spar. Examination of the airplane revealed that the right MLG down-lock bellcrank was fractured and had separated from its respective trunnion. The bellcrank bolt was sheared at the bolt head, consistent with overload. The upper end of the bellcrank remained attached to the outboard push-pull tube. The lower end of the bellcrank, which attached to the rod end fitting at the lower side link, was broken, consistent with a ductile tension failure. The fracture location was consistent with additional stress that would have been placed on the bellcrank if the landing gear was not properly rigged; however, damage to the landing gear precluded the ability to functionally check or verify whether the gear was properly rigged. Review of maintenance records revealed that the airplane had been operated for about 4 hours since its most recent annual inspection, which was performed about 2 months before the accident. At that time, maintenance, including the adjustment of the right MLG travel, was performed on the airplane. ## Factual narrative On March 20, 2014, about 1205 eastern daylight time, a Cessna 421B, N5929M, operated by a private individual, was substantially damaged while landing at the Charleston International Airport, Charleston, South Carolina. The commercial pilot and two passengers were not injured. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed for the flight that departed the Jim Hamilton L.B. Owens Airport, Columbia, South Carolina. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.According to a Federal Aviation Administration (FAA) inspector, the airplane was landing on runway 3, a 7,000-foot-long, 150-foot-wide, concrete runway. The pilot reported that he confirmed the three landing gear indicators were "in the green" while on approach, and that he performed a normal touchdown. As the airplane began the landing roll, the right main landing gear collapsed. The airplane then veered to the right and struck two runway lights, which resulted in substantial damage to the right wing rear spar. Examination of the airplane by an FAA inspector revealed that the right main landing gear down lock bellcrank was fractured and had separated from its respective trunnion. The bellcrank bolt remained installed; however, it was sheared at the bolt head consistent with overload. The trunnion forward attach point for the bellcrank was broken and not recovered. The upper end of the bellcrank remained attached to the outboard push-pull tube. The lower end of the bellcrank which attached to the rod end fitting at the lower side link was broken consistent with a ductile tension failure. Damage to the landing gear precluded the ability to functionally check or verify the landing gear system rigging. According to a representative from Cessna, the fracture location was consistent with the additional stresses that would have been placed on the bellcrank with the landing gear having not been properly rigged. Review of maintenance records revealed that the airplane had been operated for about 4 hours since its most recent annual inspection, which was performed on January 2, 2014. At that time, maintenance was performed on the airplane which included adjustment of the right main landing gear travel. ## Aircraft - Registration: [N5929M](https://openairdocs.org/deregistered/N5929M-2016-01-21), registration cancelled 2016-01-21, S/N 421B0312, built 1972 (OpenAirDocs) - Reported make and model: CESSNA 421 (B) - Registry model: [Cessna 421B](https://openairdocs.org/model/cessna-421b) (registry code 2076014) (OpenAirDocs) - Registry engine: [Continental GTSIO-520-C](https://openairdocs.org/engine/continental-gtsio-520-c) (registry code 17035, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 421B0312 - Year built: 1972 - Airframe hours: 6660 - Engines: CONT MOTOR GTSIO-520-C 374 horsepower reciprocating; CONT MOTOR GTSIO-520-C 375 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 2, 2014, 4 hours before - Departed: CUB, COLUMBIA, SC - Destination: CHS, Charleston, SC - Flight plan: IFR - Airport: CHS, Charleston Afb/Intl, runway 03, 7,000 × 150 ft, concrete - Equipment: Stall warning system, Handheld GPS, Electronic multifunction display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 27, 2012; seat: left; restraint: 3-point; flight hours: 2,760 total, 1,665 in this make and model, 2,640 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 153 °F, dew point 115 °F - Altimeter: 30.06 inHg - Observed at: CHS ## 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 20140320004709A](https://openairdocs.org/incident/20140320004709A), Mar 20, 2014: Cessna 421B, Charleston, SC, Substantial damage. On landing the right landing gear collapsed. It was found that the right main gear trunnion failed at the forward down lock bellcrank attach point. ## Docket (5 files) The files NTSB released with the investigation on January 12, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88966. 3.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 569 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435275&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Inspector Statement (item 2, .PDF, 316 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435276&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Maintenance Records (Excerpts) (item 3, .PDF, 456 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435277&FileExtension=.PDF&FileName=Maintenance%20Records%20(Excerpts)-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435278&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Investigation Photographs (item 5, .PDF, 3 photos, 566 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40435279&FileExtension=.PDF&FileName=Investigation%20Photographs-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.