# NTSB WPR11LA423: Arrow Falcon Exporters UH-1H, N205PJ, Stockton, CA, September 2, 2011 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 1, 2011, 18:40 local (Sep 2, 2011, 01:40 UTC) - Place: Stockton, CA - Coordinates: 37.929721, -121.534446 - Nearby events: https://openairdocs.org/map.md?lat=37.9297&lon=-121.5344&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report November 26, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 81680 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR11LA423 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81680/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81680 - Page: https://openairdocs.org/ntsb/WPR11LA423 ## Probable cause A total loss of engine power due to the separation of a tooth from the starter-generator drive gear, which resulted in failure of the engine oil pump and subsequent oil starvation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (turbine/turboprop): accessory drives](https://openairdocs.org/ntsb-findings/01057260): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Arrow Falcon Exporters UH-1H, 1 case](https://openairdocs.org/ntsb-findings/01057260/cases.md?model=1500001), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01057260/cases.md) - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Arrow Falcon Exporters UH-1H, 1 case](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=1500001), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Arrow Falcon Exporters UH-1H, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=1500001), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Emergency descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Arrow Falcon Exporters UH-1H, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=1500001), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-flare/touchdown: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [Arrow Falcon Exporters UH-1H, 1 case](https://openairdocs.org/ntsb-events/097/sequence.md?model=1500001), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis During cruise flight, the pilot noted a fluctuation in the engine oil pressure followed by the illumination of the red warning light indicating low oil pressure. He performed a precautionary landing, and at 10 feet above ground level, the engine lost total power. The helicopter subsequently landed hard on uneven terrain and rolled onto its left side. Postaccident examination of the engine revealed that a gear tooth on the starter-generator drive gear had separated. The separated tooth jammed the accessory gear drive train, which resulted in the failure of the engine oil pump and subsequent catastrophic engine failure due to oil starvation. The reason for the failure of the gear tooth could not be determined. ## Factual narrative On September 1, 2011, about 1840 Pacific daylight time, an Arrow Falcon Exporters, Inc., UH-1H helicopter, N205PJ, sustained substantial damage when it rolled over during an emergency landing following a total loss of engine power near Stockton, California. The commercial pilot, the sole occupant, received minor injuries. P.J. Helicopters, Red Bluff, California, was operating the helicopter under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the cross-country repositioning flight, which had originated from Tracy, California, about 10 minutes before the accident. A company visual flight rules flight plan was on file and had been activated. The pilot stated that, while in cruise flight, he noted a fluctuation in the engine oil pressure followed by the illumination of the red warning light indicating low oil pressure. As he was performing a precautionary landing, about 10 feet above ground level, the engine had a total loss of power. The helicopter subsequently landed hard on uneven terrain, and rolled onto its left side. Postaccident teardown examination of the engine, which was conducted under the supervision of a Federal Aviation Administration inspector, revealed that a gear tooth on the starter-generator drive gear had separated. The separated tooth jammed the accessory gear drivetrain, which resulted in the failure of the engine oil pump and led to catastrophic engine failure due to oil starvation. The reason for the failure of the gear tooth was not determined. ## Aircraft - Registration: [N205PJ](https://openairdocs.org/deregistered/N205PJ-2013-11-06), registration cancelled 2013-11-06, S/N 64-13617, built 1964 (OpenAirDocs) - Reported make and model: ARROW FALCON EXPORTERS INC UH-1H - Registry model: [Arrow Falcon Exporters UH-1H](https://openairdocs.org/model/arrow-falcon-exporters-uh-1h) (registry code 1500001) (OpenAirDocs) - Registry engine: [Lycoming T-53 series](https://openairdocs.org/engine/lycoming-t-53-series) (registry code 41552, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 64-13617 - Airframe hours: 15000 - Engines: LYCOMING T-53 1150 horsepower turbo shaft - Damage: Substantial damage - Flight: Positioning, Part 91 - Operator: P J Helicopters Inc - Registered owner: P J Helicopters Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, August 8, 2011 - Departed: TCY, Tracy, CA - Destination: RBL, Red Bluff, CA - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: minor; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review March 4, 2011; seat: right; flight hours: 13,200 total, 13,050 as pilot in command, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 91 °F, dew point 52 °F - Altimeter: 29.75 inHg - Observed at: SCK, 14 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 20110901022849A](https://openairdocs.org/incident/20110901022849A), Sep 1, 2011: Arrow Falcon Exporters Inc UH-1H, Trull, CA, Substantial damage. The pilot reported that while in cruise flight he noted a low oil indication to the engine. As pilot was performing a precautionary landing, the engine had a… ## Docket (4 files) The files NTSB released with the investigation on August 24, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81680. 2.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 620 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375370&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation - Engine Teardown (item 2, .PDF, 25 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375371&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Engine%20Teardown%20-Master.PDF - Photo 1. Helicopter at accident site (item 3, .PDF, 449 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375372&FileExtension=.PDF&FileName=Photo%201.%20Helicopter%20at%20accident%20site-Master.PDF - Photo 2. Broken gear tooth on drive gear (item 4, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375373&FileExtension=.PDF&FileName=Photo%202.%20Broken%20gear%20tooth%20on%20drive%20gear%20-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.