# NTSB CEN14LA107: Piper PA 24-250, N6767P, Silver City, NM, January 3, 2014 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 3, 2014, 15:15 local (22:15 UTC) - Place: Silver City, NM - Coordinates: 32.689296, -108.129402 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.6893&lon=-108.1294&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: 1 uninjured - Status: Completed, report September 24, 2014 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA -- Albuquerque Flight Standards - NTSB case key (mKey): 88653 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN14LA107 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/88653/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=88653 - Page: https://openairdocs.org/ntsb/CEN14LA107 ## Probable cause The collapse of the landing gear during landing for reasons that could not be determined during postaccident examinations. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Piper PA-24-250, 14 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=7102404), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Piper PA-24-250, 13 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=7102404), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Piper PA-24-250, 9 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7102404), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Piper PA-24-250, 11 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7102404), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot reported that he lowered the landing gear and observed gear-down indications before touchdown; however, the landing gear collapsed during the landing. A postaccident examination of the airplane revealed that all three landing gear had collapsed; no anomalies in the extension/retraction linkage were found. The airplane owner reported that, during recovery of the airplane, he had adjusted the nose landing gear actuating rod for the nose gear to fully seat on the stop flats. Additionally, the landing gear had been serviced during the most recent annual inspection, which was about 24 flight hours before the accident. Although it is possible that the landing gear was not properly adjusted after the maintenance work, several flights had been conducted in the interim without any reported issues related to the landing gear system. Postaccident examinations revealed that the nose landing gear down lock switch was improperly mounted upside down and that the limit switch was stuck in the closed position. The inoperative nose landing gear switch would have provided a gear down/locked indication to the pilot regardless of the nose landing gear condition. It is possible that the nose landing gear did not fully extend and lock down before landing due to either the inoperative limit switch or a slight misrigging of the system. However, because the landing gear was operated by the transmission jackscrew, it is unlikely that an issue with the nose landing gear would have caused a collapse of the main landing gear if the main landing gear was fully extended and locked in the down position. The reason for the landing gear collapse could not be determined. ## Factual narrative On January 3, 2014, about 1515 mountain standard time, a Piper PA-24-250, N6767P, sustained substantial damage when the landing gear collapsed during landing at the Grant County Airport (SVC), Silver City, New Mexico. The pilot was not injured. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from the Deming Municipal Airport (DMN), Deming, New Mexico, about 1430. The pilot reported that he lowered the landing gear on downwind and observed a gear down indication before touchdown. He noted that the approach was normal; however, the landing gear collapsed during the landing rollout.A postaccident examination was conducted by a Federal Aviation Administration (FAA) inspector after recovery of the airplane. All three landing gear had collapsed. Damage included bent and buckled fuselage frames. The examination did not reveal any anomalies in the extension/retraction linkage. However, it was noted that the nose landing gear down lock switch was improperly mounted upside-down and was not making contact with the striker plate. Further examination revealed that the limit switch plunger was stuck in the closed position. The airplane owner informed the assigned FAA inspector that after the accident, he adjusted the nose landing gear actuating rod in order for the nose landing gear to fully seat on the stop flats. A mechanic noted that there may have been damage to one of the frames, causing the nose landing gear to become out of rig. However, the FAA inspector reported that there appeared to be no movement of the landing gear transmission mounting at the time of the postaccident examination. Maintenance records indicated that the landing gear had been serviced during the most recent annual inspection. This included repair of the gear motor transmission, a rebuild of all three landing gear struts, and replacement of the bungee cords. The maintenance work and inspection was completed on April 11, 2013, at a recording tachometer time of 2,862 hours. The tachometer indicated 2,886 hours at the time of the accident. The landing gear retraction mechanism included push-pull cables to each main gear and a push-pull tube to the nose gear. The transmission motor installed below the cabin floor drove the transmission screw (jackscrew), which in turn actuated the push-pull cables and push-pull tube to extend or retract the landing gear. Limit switches installed on each gear assembly would stop the transmission motor when the landing gear was fully extended or retracted. These switches also operated indicator lights in the cabin. A safety switch was located on the left main gear assembly in order to prevent the gear from retracting while the airplane was on the ground. ## Aircraft - Registration: [N6767P](https://openairdocs.org/deregistered/N6767P-2018-02-16), registration cancelled 2018-02-16, S/N 24-1897, built 1960 (OpenAirDocs) - Reported make and model: PIPER PA 24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-1897 - Year built: 1960 - Airframe hours: 4500 - Engines: LYCOMING 0-540-A1B5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 30, 2013, 24 hours before - Departed: DMN, Deming, NM - Destination: DMN, Deming, NM - Airport: SVC, Grant County, runway 26, 6,802 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review November 15, 2012; seat: left; restraint: lap only; flight hours: 900 total, 350 in this make and model, 900 as pilot in command, 9 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 12 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 18 °F - Altimeter: 30.04 inHg - Observed at: SVC ## 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 20140103000479A](https://openairdocs.org/incident/20140103000479A), Jan 3, 2014: Piper PA-24-250, Silver City, NM, Substantial damage. Upon landing at Silver City Grant County Airport, the nose gear collapsed followed by the main gear collapsing. Inspection revealed that improper maintenance… ## Docket (5 files) The files NTSB released with the investigation on April 17, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=88653. 3.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411286&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411287&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Record of Conversation (item 3, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411288&FileExtension=.PDF&FileName=Record%20of%20Conversation-Master.PDF - Maintenance Logbook - Excerpt (item 4, .PDF, 286 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411289&FileExtension=.PDF&FileName=Maintenance%20Logbook%20-%20Excerpt-Redacted.PDF - Service Manual - Excerpt (Landing Gear System) (item 5, .PDF, 200 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40411290&FileExtension=.PDF&FileName=Service%20Manual%20-%20Excerpt%20(Landing%20Gear%20System)-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.