# NTSB ANC05LA079: Cessna 206, N2125F, Stony River, AK, June 6, 2005 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 5, 2005, 17:15 local (Jun 6, 2005, 01:15 UTC) - Place: Stony River, AK - Coordinates: 61.783332, -156.591949 - Nearby events: https://openairdocs.org/map.md?lat=61.7833&lon=-156.5919&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report June 28, 2006 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration, NTSB - NTSB case key (mKey): 61633 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC05LA079 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61633/pdf - Page: https://openairdocs.org/ntsb/ANC05LA079 ## Probable cause A partially blocked fuel pump, which resulted in a loss of engine power while in cruise flight. A factor associated with the accident was an inoperative electric auxiliary fuel pump. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - normal - fuel system,pump - blocked(partial) (cause) - fuel system,electric boost pump - inoperative (contributing factor) - Forced landing, descent - emergency - In flight collision with object, emergency descent/landing - object - tree(s) - On ground/water encounter with terrain/water, emergency landing - terrain condition - ground - Nose over, emergency descent/landing ## Analysis The private pilot reported that while in cruise flight, during a Title 14, CFR Part 91 cross-country personal flight, all engine power was lost. While performing emergency engine procedures, he activated the electric auxiliary fuel pump, and noted that the engine fuel pressure was reading zero. Unable to restore engine power, he selected an open area that was surrounded by trees as an emergency landing area. The airplane landed short of the intended landing site, struck a large stand of trees, and nosed over. The airplane sustained substantial damage to the wings, fuselage, and empennage. A postaccident inspection of the airplane's fuel system components revealed that the electric auxiliary fuel pump was inoperative, and the vapor injector orifice in the engine driven fuel pump was blocked by a 1/8-inch long metal shaving. ## Factual narrative On June 5, 2005, about 1715 Alaska daylight time, a wheel-equipped Cessna 206 airplane, N2125F, sustained substantial damage when it collided with trees during a forced landing following a loss of engine power while in cruise flight, about 9 miles west of Stony River, Alaska. The airplane was being operated as a visual flight rules (VFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The certificated private pilot, and the two passengers, sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at the Palmer Municipal Airport, Palmer, Alaska, about 1520, and was en route to Aniak, Alaska. During a telephone conversation with the National Transportation Safety Board investigator-in-charge on June 6, the pilot reported that while in cruise flight about 4,000 feet above the ground, all engine power was lost. He said that while performing emergency engine procedures he activated the electric auxiliary fuel pump, and switched the fuel valve from the left tank to the right tank, even though each fuel tank contained adequate fuel. The pilot said while performing the emergency engine procedures, he noted that the engine fuel pressure was reading zero. He was unable to restore engine power, and selected an open area surrounded by trees as an emergency landing area. The airplane landed short of the intended landing site, struck a large stand of trees, and nosed over. The airplane sustained substantial damage to the wings, fuselage, and empennage. The pilot stated during the June 6 telephone conversation that about a month before the accident flight, he had recurring difficulty starting the airplane's engine. He said that he was unable to prime the engine with fuel due to a lack of fuel pressure from the electric fuel boost pump, but assumed the problem was associated with a fuel system vapor-lock condition. He reported that once the engine was started, it continued to operate normally. The accident airplane was equipped with a Dukes, Inc., 24 volt, rotary style electric auxiliary fuel pump. A 2-inch long drive shaft connects the electric motor to the rotary pump assembly. A 1/2-inch diameter rotor, located within the pump assembly, is equipped with 4 nylatron vanes. A 1/4-inch long shear pin interconnects the rotor to the drive shaft during fuel boost pump operation. On December 13, under the direction of the NTSB IIC, the accident airplane's electric auxiliary fuel pump was placed on a fuel system test stand at Alaskan Aircraft Engines, Inc., Anchorage, Alaska. When electrical power was applied to the pump assembly, the electric motor portion of the pump operated normally. However, during initial operation, intermittent and erratic fuel pressure fluctuations were observed, followed by a total loss of fuel pressure. The electric motor continued to operate after all fuel pressure was lost. The electric auxiliary fuel pump was disassembled, which disclosed that the 1/4-inch long shear pin was fractured. Examination of the 2-inch long drive shaft revealed that a portion of the remaining shear pin would intermittently engage the 1/2-inch diameter rotor, but failed to provide a continuous connection between the electric motor and the rotor assembly. On December 14, under the direction of an NTSB air safety investigator, the accident airplane's engine driven fuel pump assembly was placed on a fuel system test stand at Firewall Forward, Inc., Fort Collins, Colorado. The NTSB investigator reported "a disruption (air/foam) in the output fuel flow" while the engine driven fuel pump was being operated on the fuel system test stand. The investigator noted that when an auxiliary fuel pump was activated, a pump that simulates the airplane's electric auxiliary fuel pump, the engine driven fuel pump operated normally. The fuel pump was subsequently disassembled, which revealed that a 1/8-inch metal shaving blocked the vapor injector orifice. The metal shaving was then removed from the vapor injector orifice, the pump was reassembled, and again placed on the fuel system test stand. The pump then operated in accordance with the manufacturer's specifications. ## Aircraft - Registration: [N2125F](https://openairdocs.org/deregistered/N2125F-2006-02-08), registration cancelled 2006-02-08, S/N U206-0325, built 1964 (OpenAirDocs) - Reported make and model: Cessna 206 - Registry model: [Cessna U206](https://openairdocs.org/model/cessna-u206) (registry code 2073306) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: U206-0325 - Airframe hours: 9055.5 - Engines: Continental IO-520 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Douglas O. Moffitt - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 1, 2004 - Departed: PAQ, PALMER, AK - Destination: ANI, Aniak, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: minor; private; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review January 1, 2005; seat: left; flight hours: 4,600 total, 2,000 in this make and model, 4,550 as pilot in command, 30 in the last 90 days, 25 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 64 °F ## 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 20050605014919A](https://openairdocs.org/incident/20050605014919A), Jun 5, 2005: Cessna U206, Stony River, AK, Substantial damage. (-23) According to the initial NTSB report - the pilot reported he departed pdq, 6-5-05. The weather was not a factor, about 2 hours into the flight, at 4000… ## Other investigations on N2125F (2) 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. - [NTSB ANC74AA051](https://openairdocs.org/ntsb/ANC74AA051), Jan 5, 1974: Cessna U206 (N2125F), St Marys, AK, substantial damage - [NTSB ANC74DAG68](https://openairdocs.org/ntsb/ANC74DAG68), Oct 15, 1973: Cessna U206 (N2125F), Akiak, AK, substantial damage 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.