# NTSB GAA17CA570: Piper PA 31, N4078J, Saipan, August 30, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 30, 2017 - Place: Saipan - Coordinates: 15.117777, 145.726104 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=15.1178&lon=145.7261&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Birdstrike](https://openairdocs.org/ntsb-events/901) - Highest injury: No injuries - Injuries: 7 uninjured - Status: Completed, report April 23, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 96145 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA570 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96145/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96145 - Page: https://openairdocs.org/ntsb/GAA17CA570 ## Probable cause Impact with multiple birds while retracting the landing gear, which resulted in the subsequent failure of the right inboard main landing gear door actuator hose and prevented the pilot from being able to extend the landing gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Object/animal/substance: animal(s)/bird(s)](https://openairdocs.org/ntsb-findings/03022045): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Piper PA-31-350, 5 cases](https://openairdocs.org/ntsb-findings/03022045/cases.md?model=7103110), [All aircraft, 358 cases](https://openairdocs.org/ntsb-findings/03022045/cases.md) - [Hydraulic power system: hydraulic, main system](https://openairdocs.org/ntsb-findings/01022910): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Piper PA-31-350, 1 case](https://openairdocs.org/ntsb-findings/01022910/cases.md?model=7103110), [All aircraft, 27 cases](https://openairdocs.org/ntsb-findings/01022910/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Birdstrike](https://openairdocs.org/ntsb-events/901) (defining event); cases with it: [Piper PA-31-350, 5 cases](https://openairdocs.org/ntsb-events/901/sequence.md?model=7103110), [All aircraft, 253 cases](https://openairdocs.org/ntsb-events/901/sequence.md) - [Approach-IFR final approach: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Piper PA-31-350, 2 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7103110), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330); cases with it: [Piper PA-31-350, 6 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7103110), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Piper PA-31-350, 8 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7103110), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot reported that, during the initial climb, about 150 ft above the ground, while the landing gear were being retracted, the airplane impacted a flock of medium-sized birds. He noted that the landing gear unlock indicator remained illuminated and that the landing gear handle would not return to the up neutral position. No degradation of performance was noted, so the pilot chose to continue to his destination. About 20 miles from the airport, the pilot attempted to lower the landing gear but was unsuccessful. He contacted maintenance personnel on the ground and advised them of the landing gear issue. The ground maintenance personnel visually verified that the nose and right main landing gear (MLG) were down. The pilot performed the emergency gear extension checklist and noted little to no resistance on the hand pump. The pilot made multiple attempts to lower the landing gear without success. During the landing, the right MLG collapsed, and the left wing impacted the ground. The airplane sustained substantial damage to the fuselage. Postaccident examination revealed snarge on both horizonal stabilizers, the left wing, and the fuselage and that the right inboard MLG door actuator hose had failed. ## Factual narrative The pilot reported that during the initial climb, about 150 feet above the ground, while the landing gear was being retracted, the airplane impacted a flock of medium sized birds. He noted that the landing gear unlock indicator remained illuminated and the landing gear handle would not return to the up neutral position. No degradation of performance was noted, so the pilot choose to continue to his destination. About 20 miles from the airport, the pilot attempted to lower the landing gear, but was unsuccessful. He contacted maintenance personnel on the ground and advised them of the landing gear issue. The ground maintenance personnel visually verified that the nose and right main landing gear were down. The pilot performed the emergency gear extension checklist and noted little to no resistance on the hand pump. After multiple attempts to lower the landing gear, Airport Rescue and Fire Fighting Support was requested. Soon after, the pilot received clearance to land. During the landing the right main landing gear collapsed and the left wing impacted the ground. The airplane sustained substantial damage to the fuselage. A postaccident examination revealed snarge on both horizonal stabilizers, left wing, and fuselage. It was noted that the right inboard main landing gear door actuator hose had failed. ## Aircraft - Registration: [N4078J](https://openairdocs.org/aircraft/N4078J), registered now, S/N 31-8152057, built 1980 (OpenAirDocs) - Reported make and model: PIPER PA 31 (350) - Registry model: [Piper PA-31-350](https://openairdocs.org/model/piper-pa-31-350) (registry code 7103110) (OpenAirDocs) - Registry engine: [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series) (registry code 41533, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 31-8152057 - Year built: 1980 - Airframe hours: 9341.1 - Engines: LYCOMING TIO-540-J2BD 350 horsepower reciprocating; LYCOMING TIO-540-J2BD 350 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Star Marianas Air, Inc. - Registered owner: Marianas Transportation Management Solut - Airworthiness certificate: Standard, Normal - Last inspection: Continuous airworthiness, August 2, 2017 - Departed: GRO, ROTA ISLAND - Destination: GSN, Saipan - Flight plan: IFR - Airport: GSN, Francisco C Ada/Saipan Intl, runway 24, 7,001 × 100 ft, asphalt - Equipment: Stall warning system, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 18, 2017; seat: left; restraint: 3-point; flight hours: 5,847 total, 2,005 in this make and model, 5,714 as pilot in command, 186 in the last 90 days, 128 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 11,000 ft broken - Temperature: 81 °F, dew point 75 °F - Altimeter: 29.79 inHg - Observed at: PGSF ## 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 20170830014039A](https://openairdocs.org/incident/20170830014039A), Aug 30, 2017: Piper PA-31-350, Saipan, CM, Minor damage. Shortly after becoming airborne at approximately 150 feet AGL, near the departure end of runway 27, and during the landing gear retraction phase of flight, the… ## Docket (3 files) The files NTSB released with the investigation on March 12, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96145. 3.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 947 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460799&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - 78J Damage Report with Pictures (item 2, .PDF, 16 photos, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460800&FileExtension=.PDF&FileName=78J%20Damage%20Report%20with%20Pictures-Master.PDF - Accident Photos (item 3, .PDF, 2 photos, 207 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460801&FileExtension=.PDF&FileName=Accident%20Photos-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.