# NTSB ANC09LA065: Noorduyn UC-64A, N225BL, Akiachak, AK, July 11, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 11, 2009, 13:00 local (21:00 UTC) - Place: Akiachak, AK - Coordinates: 60.905834, -161.426391 - Nearby events: https://openairdocs.org/map.md?lat=60.9058&lon=-161.4264&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: No injuries - Injuries: 2 uninjured - Status: Completed, report May 11, 2010 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA FSDO-03 - NTSB case key (mKey): 74291 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC09LA065 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74291/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74291 - Page: https://openairdocs.org/ntsb/ANC09LA065 ## Probable cause The loss of engine power due to the failure of a crankshaft component, resulting in an off-airport landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Noorduyn UC-64A, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=6330204), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/cases.md) - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Noorduyn UC-64A, 1 case](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=6330204), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/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: [Noorduyn UC-64A, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=6330204), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Noorduyn UC-64A, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=6330204), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Noorduyn UC-64A, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=6330204), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airline transport pilot was on a Title 14, CFR Part 135 passenger flight. The pilot said during cruise flight he heard a loud bang, and the engine started running rough. He said he diverted to the nearest airport, but the engine quit completely, and he was unable to reach the runway. The airplane subsequently collided with terrain, sustaining substantial damage to both wings and the fuselage. An examination of the engine revealed that a locking screw had backed out of one of the anti-vibration counterweights on the crankshaft, scoring the interior back surface of the engine case. The unsecured counterweight then moved from its position in the crankshaft, and was likely struck by the engine's master rod, which shattered the weight, and liberated it from its normal location. The liberated counterweight was struck by internal moving parts, creating several component failures, and ultimately an engine seizure. ## Factual narrative On July 11, 2009, about 1300 Alaska daylight time, a Noordyun UC-64A (Norseman) airplane, N225BL, sustained substantial damage following a loss of engine power and an emergency landing about 300 feet short of runway 1 at the Akiachak Airport, Akiachak, Alaska. The airplane was being operated as a visual flight rules (VFR) passenger flight under Title 14, CFR Part 135, by Renfro's Alaska Adventures, Bethel, Alaska. The pilot and sole passenger were not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 12, the pilot said he was flying from Bethel to Tuluksak, Alaska, when the engine started to run rough. He said he diverted to Akiachak which was near their position. The pilot said the engine quit completely, and he was unable to reach the runway. The airplane collided with terrain about 300 feet short of runway 1. The pilot said the engine had been rebuilt about 100 flight hours prior to the accident, after developing problems following a previous rebuild. He said that the airplane sustained substantial damage to both wings and the fuselage during the accident. An internal examination of the engine by the NTSB IIC on November 6, showed that a locking screw had backed out of one of the two anti-vibration counterweights on the crankshaft, and scored the interior back surface of the engine case. The locking screw was not located. The engine case and oil passages had fractured metal pieces from piston skirts, piston rings, and ground pieces of connecting rods. A large part of the crankshaft counterweight and half of bolt that normally secures the counterweight halves were found in a piston cylinder. The other half of the counterweight was found in the crankcase; it was fractured into three large and many smaller pieces. The second counterweight was still bolted in its proper place. Piston heads were found in the crankcase, and the engine's master rod was bent. ## Aircraft - Registration: [N225BL](https://openairdocs.org/deregistered/N225BL-2021-07-03), registration cancelled 2021-07-03, S/N 542, built 1943 (OpenAirDocs) - Reported make and model: NOORDUYN UC-64A - Registry model: [Noorduyn UC-64A](https://openairdocs.org/model/noorduyn-uc-64a) (registry code 6330204) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 542 - Airframe hours: 15729 - Engines: P&W R1340 SERIES 600 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Renfro Michael W, doing business as Renfro's Alaskan Adventures - Registered owner: Renfro Michael W - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 6, 2009, 20 hours before - Departed: PABE, Bethel, AK - Destination: TLT, Tuluksak, AK - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: none; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review April 1, 2009; seat: left; flight hours: 8,500 total, 100 in this make and model, 7,200 as pilot in command, 180 in the last 90 days, 100 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 40 statute miles - Lowest ceiling: none - Temperature: 61 °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 20090711025289A](https://openairdocs.org/incident/20090711025289A), Jul 11, 2009: Noorduyn UC-64A, Akiachak, AK, Substantial damage. Aircraft failed to maintain cruise altitude due to loss of engine power. Pilot attempted emergency landing at Akiachak Airport. Ground contact was made short… ## Other investigations on N225BL (1) 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 ANC01LA062](https://openairdocs.org/ntsb/ANC01LA062), Jun 4, 2001: Noorduyn UC-64A (N225BL), Seward, AK, substantial damage. Probable cause: The pilot's inadvertent stall of the airplane during takeoff. Factors associated with the accident were the pilot's inadequate weather evaluation, his inadequate compensation for wind conditions, and… ## Docket (2 files) The files NTSB released with the investigation on March 26, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74291. 825 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 755 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327603&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Statement from JP Air Service LLC - Director of Operations (item 2, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327604&FileExtension=.PDF&FileName=Statement%20from%20JP%20Air%20Service%20LLC%20-%20Director%20of%20Operations-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.