# NTSB ANC10LA061: Piper PA-14, N5126H, King Salmon, AK, July 15, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 15, 2010, 11:37 local (19:37 UTC) - Place: King Salmon, AK - Coordinates: 58.761665, -156.608337 - Nearby events: https://openairdocs.org/map.md?lat=58.7617&lon=-156.6083&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report September 19, 2011 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 76646 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC10LA061 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/76646/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=76646 - Page: https://openairdocs.org/ntsb/ANC10LA061 ## Probable cause The pilot's failure to use continuous carburetor heat while operating in carburetor icing conditions, resulting in carburetor ice and subsequent partial loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Piper PA-14, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=7101402), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-14, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7101402), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Piper PA-14, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=7101402), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-14, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101402), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the weather at his destination airport had deteriorated to a 500-700 foot ceiling with 10 miles of visibility. He was instructed by air traffic control personnel to hold outside the airport's controlled airspace, and to expect a special visual flight rules clearance in 30 minutes. Throughout the hold, the pilot cycled the carburetor heat intermittently on and off. After about 25 minutes holding, he decided to reposition to a location between his destination and alternate airport. As he started to fly towards this new position, the engine began losing rpm and running rough. He applied carburetor heat and full mixture, but the engine continued to run rough. He made a forced landing along the edge of a stream, during which the right wing and fuselage received substantial damage. About the time of the accident, the destination airport reported both the temperature and dew point as 07 degrees Celsius. According to the Federal Aviation Administration Carburetor Icing Probability Chart, an aircraft encountering those ambient conditions could expect serious carburetor icing while at cruise power. Examination of the airplane and engine revealed no mechanical failures or malfunctions that would have precluded normal operation. ## Factual narrative On July 15, 2010, at 1137 Alaska daylight time, a Piper PA-14, N5126H, had a loss of engine power and collided with terrain during the subsequent forced landing along a stream bank, about 6 miles north of King Salmon, Alaska. The airline transport pilot operated the airplane under the provisions of 14 Code of Federal Regulations, Part 91. The pilot and three passengers were not injured. The airplane sustained substantial damage to the right wing and fuselage. Instrument meteorological conditions prevailed, and no flight plan had been filed. The flight originated at Igiugig, Alaska, at 1030. The pilot reported to the Safety Board investigator that the weather had deteriorated between a 500 to 700 foot ceiling and 10 mile visibility as he approached King Salmon. He was instructed to hold north, outside the King Salmon class D airspace, and to expect special VFR clearance in 30 minutes. Throughout the hold the pilot cycled the carburetor heat intermittently on and off. After about 25 minutes holding, he decided to reposition to a location between King Salmon and his alternate, Naknek Airport. As he started to proceed towards this new position, the engine began losing rpm and running rough. He applied carburetor heat, full mixture, but the engine continued to run rough. The pilot made a forced landing along the edge of a stream and the airplane came to rest on the embankment. The King Salmon METAR for 1154 recorded winds from 210 degrees at 8 knots, 7 statute miles visibility, 500 foot overcast, temperature 7 degrees Celsius, dew point 7 degrees Celsius, and altimeter 30.20 in hg. An FAA inspector performed an on-site exam, both of which had clean fuel. The carburetor floats and internal accelerator pump appeared to function normally. The fuel had drained out from the airplane's fuel tanks at the accident site, therefore, the fuel quantity on board the airplane could not be verified. The pilot reported having about 1/4 tank fuel remaining in both tanks prior to the accident. First responders reported seeing fuel leaking from the damaged wing. The FAA published Special Airworthiness Information Bulletin (SAIB) CE-09-35 on June 30, 2009, regarding carburetor ice prevention. The SAIB noted that carburetor icing does not just occur in freezing conditions; it can occur at temperatures well above freezing temperatures when there is visible moisture or high humidity. It states that icing can occur in the carburetor at temperatures above freezing. Vaporization of fuel combined with the expansion of air as it flows through the carburetor (the venturi effect) causes sudden cooling. A significant amount of ice can build up within a fraction of a second. The SAIB contains a graph that illustrates the probability of carburetor icing for various temperatures, dew points, and relative humidity conditions. According to the SAIB, a pilot encountering the ambient conditions reported by the King Salmon METAR could expect serious carburetor icing while at cruise power. ## Aircraft - Registration: [N5126H](https://openairdocs.org/aircraft/N5126H), registered now, S/N 14-135, built 1948 (OpenAirDocs) - Reported make and model: PIPER PA-14 - Registry model: [Piper PA-14](https://openairdocs.org/model/piper-pa-14) (registry code 7101402) (OpenAirDocs) - Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 14-135 - Airframe hours: 4408 - Engines: LYCOMING O-290 SERIES 140 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Bradbury Douglas - Registered owner: Bradbury Douglas - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 18, 2010 - Departed: KAIG, Igiugig, AK - Destination: PAKN, King Salmon, AK - Airport: PAKN, King Salmon ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; airline transport, commercial, private, flight instructor; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 3; last flight review March 12, 2010; seat: right; flight hours: 5,089 total, 229 in this make and model, 3,353 as pilot in command, 74 in the last 90 days, 31 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 210° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: 500 ft overcast - Temperature: 45 °F, dew point 45 °F - Altimeter: 30.20 inHg - Observed at: PAKN, 5 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 20100715038319A](https://openairdocs.org/incident/20100715038319A), Jul 15, 2010: Piper PA-14, King Salmon, AK, Substantial damage. Engine started running rough and got worse when carb heat was selected. Pilot was forced to land at the first available clearing 5 miles west of pakn airport.… ## Docket (4 files) The files NTSB released with the investigation on July 1, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=76646. 3.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345776&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1 - Front View of Airplane (item 2, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40350490&FileExtension=.PDF&FileName=Photo%201%20-%20Front%20View%20of%20Airplane-Master.PDF - Photo 2 - Aerial View of Airplane (item 3, .PDF, 548 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40350491&FileExtension=.PDF&FileName=Photo%202%20-%20Aerial%20View%20of%20Airplane-Master.PDF - SAIB CE-09-35, Carb Ice (item 4, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345778&FileExtension=.PDF&FileName=SAIB%20CE-09-35,%20Carb%20Ice-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.