# NTSB CEN13IA059: Fairchild SA227-AC, N619BA, Minneapolis, MN, November 10, 2012 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: November 9, 2012, 20:07 local (Nov 10, 2012, 02:07 UTC) - Place: Minneapolis, MN - Coordinates: 44.875831, -93.219718 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.8758&lon=-93.2197&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 January 14, 2015 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Minneapolis FSDO - NTSB case key (mKey): 85616 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN13IA059 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85616/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85616 - Page: https://openairdocs.org/ntsb/CEN13IA059 ## Probable cause Loose electrical connections to the hydraulic system and anomalies in the hydraulic shuttle valve and power pack, which resulted in an uncommanded gear unlock and collapse of the left main landing gear. Contributing to the accident was the operator’s failure to comply with the life limits outlined by the hydraulic power pack’s manufacturer. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Hydraulic power system: hyd pwr sys wiring](https://openairdocs.org/ntsb-findings/01022997): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Fairchild SA227-AC, 1 case](https://openairdocs.org/ntsb-findings/01022997/cases.md?model=3377509), [All aircraft, 1 case](https://openairdocs.org/ntsb-findings/01022997/cases.md) - [Hydraulic power system: pump, main](https://openairdocs.org/ntsb-findings/01022913): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Fairchild SA227-AC, 1 case](https://openairdocs.org/ntsb-findings/01022913/cases.md?model=3377509), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01022913/cases.md) - [Policy/procedure](https://openairdocs.org/ntsb-findings/04021000): Organizational issues › Management · Operator (probable cause); cases with it: [Fairchild SA227-AC, 1 case](https://openairdocs.org/ntsb-findings/04021000/cases.md?model=3377509), [All aircraft, 15 cases](https://openairdocs.org/ntsb-findings/04021000/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Not specified (probable cause); cases with it: [Fairchild SA227-AC, 1 case](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=3377509), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/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: [Fairchild SA227-AC, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=3377509), [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: [Fairchild SA227-AC, 3 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=3377509), [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: [Fairchild SA227-AC, 4 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=3377509), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis All three green landing gear indicator lights were illuminated before the pilot landed the airplane. About 50 to 100 feet beyond the touchdown point, the left main landing gear collapsed and the airplane exited the left side of runway. A postincident examination of the airplane found two loose electrical connections to the hydraulic system and several anomalies in the hydraulic shuttle valve and the hydraulic power pack. It is likely that the hydraulic issues allowed for a movement in the landing gear shuttle valve, which resulted in an uncommanded gear unlock and subsequent collapse of the left main landing gear. The hydraulic power pack's manufacturer had issued a service letter regarding life limits on the pack; however, the operator was not in compliance with these limits at the time of the accident. ## Factual narrative On November 9, 2012, about 2007 central standard time, N619BA, a Fairchild Aircraft, Inc., SA227-AC, multi-engine airplane, sustained minor damage when the left main landing gear collapsed during landing at Minneapolis St. Paul International Airport (MSP), Minneapolis, Minnesota. The pilot was not injured. The airplane was registered to and operated by Bemidji Aviation Services, Inc. Night visual meteorological conditions (VMC) prevailed at the time of the accident and an instrument flight rules (IFR) flight plan had been filed for the 14 Code of Federal Regulations Part 135 scheduled cargo flight. The airplane departed Duluth International Airport (DLH), Duluth, Minnesota, about 1926 destined for MSP.The pilot reported that all three green landing gear indicator lights were illuminated before he performed an otherwise normal landing. About 50 to 100 feet after touching down on the runway, the left main landing gear collapsed. The airplane skidded off of the left side of runway and came to rest upright in the grass. A postincident examination of the airplane found two loose electrical connections to the hydraulic system. An overhaul teardown of the hydraulic shuttle valve showed the seat out of tolerance, cap safety wire holes damaged and a washer not to the current revisions. The washer also showed corrosion. An examination of the hydraulic power pack revealed a washer not to the current revision. The system operated normally after the electrical wiring was repaired, and the hydraulic power pack and shuttle valve were replaced. The operator reported that they have revised their life limitations on the hydraulic power pack so that it now complies with the instructions in the manufacturer's service letter. ## Aircraft - Registration: [N619BA](https://openairdocs.org/aircraft/N619BA), registered now, S/N AC619B, built 1985 (OpenAirDocs) - Reported make and model: FAIRCHILD SA227-AC - Registry model: [Fairchild SA227-AC](https://openairdocs.org/model/fairchild-sa227-ac) (registry code 3377509) (OpenAirDocs) - Registry engine: [Garrett TPE331-11UA](https://openairdocs.org/engine/garrett-tpe331-11ua) (registry code 29074, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: AC619B - Year built: 1985 - Engines: GARRETT TPE331-11UA 1000 horsepower turbo prop; GARRETT TPE331-11UA 1000 horsepower turbo prop - Damage: Minor damage - Flight: Part 135 - Operator: Bemidji Aviation Services Inc, doing business as Bemidji Aviation Services Inc - Registered owner: Bemidji Aviation Services Inc - Airworthiness certificate: Standard, Normal - Departed: DLH, Duluth, MN - Destination: MSP, Minneapolis, MN - Flight plan: IFR - Airport: MSP, Minneapolis St Paul Intl, runway 12R, 10,000 × 200 ft, concrete - Equipment: Stall warning system, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: none; airline transport, flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 5, 2012; seat: left; restraint: 4-point; flight hours: 12,500 total, 500 in this make and model, 12,000 as pilot in command, 90 in the last 90 days, 30 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 70° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft overcast - Temperature: 46 °F, dew point 37 °F - Altimeter: 29.95 inHg - Observed at: KMSP ## 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 20121109024119I](https://openairdocs.org/incident/20121109024119I), Nov 9, 2012: Fairchild SA227-AC, Minneapolis, MN, Minor damage. Aircraft made normal landing on runway 12R at msp. All 3 green landing gear indicator lights were illuminated before touchdown according to pilot. After 50 to… ## Docket (3 files) The files NTSB released with the investigation on December 15, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85616. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 631 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420061&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Mechanic's Statement (item 2, .PDF, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420062&FileExtension=.PDF&FileName=Mechanic%27s%20Statement-Master.PDF - Tear Down Report of the Failed Flap Valve and Failed Power Pack (item 3, .PDF, 523 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40420063&FileExtension=.PDF&FileName=Tear%20Down%20Report%20of%20the%20Failed%20Flap%20Valve%20and%20Failed%20Power%20Pack-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.