# NTSB ANC09LA042: Piper PA-24-250, N7440P, Wasilla, AK, May 16, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 16, 2009, 11:40 local (19:40 UTC) - Place: Wasilla, AK - Coordinates: 61.571388, -149.470275 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.5714&lon=-149.4703&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 11, 2010 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration (Airworthiness) - NTSB case key (mKey): 73853 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC09LA042 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73853/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73853 - Page: https://openairdocs.org/ntsb/ANC09LA042 ## Probable cause A loss of engine power due to the blockage of the carburetor air inlet by a piece of engine baffling. Contributing to the accident was a worn engine baffle, and the pilot/owner's failure to have the engine baffle replaced. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Power plant: air intake](https://openairdocs.org/ntsb-findings/01057160): Aircraft › Aircraft power plant · Not specified (probable cause); cases with it: [Piper PA-24-250, 1 case](https://openairdocs.org/ntsb-findings/01057160/cases.md?model=7102404), [All aircraft, 50 cases](https://openairdocs.org/ntsb-findings/01057160/cases.md) - [Power plant: eng air baffle sec (recip.)](https://openairdocs.org/ntsb-findings/01057112): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Piper PA-24-250, 1 case](https://openairdocs.org/ntsb-findings/01057112/cases.md?model=7102404), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01057112/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-24-250, 2 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=7102404), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Piper PA-24-250, 23 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7102404), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Ditching](https://openairdocs.org/ntsb-events/441); cases with it: [Piper PA-24-250, 2 cases](https://openairdocs.org/ntsb-events/441/sequence.md?model=7102404), [All aircraft, 186 cases](https://openairdocs.org/ntsb-events/441/sequence.md) ## Analysis The private pilot was on a Title 14, CFR Part 91, local area personal flight when the accident occurred. As he approached his destination airport he applied full carburetor heat, which resulted in a loss of engine power. After completing emergency engine procedures he was unable to restore engine power, and selected a shallow lake as a forced landing site. The airplane sustained substantial damage to the fuselage during the forced landing. The pilot reported that while the airplane was being disassembled after recovery, his mechanic removed the lower engine cowling, and discovered a worn, 4 inch by 2 inch portion of rubberized baffling material lodged inside of the carburetor air box assembly. An NTSB investigator traced the origin of the baffling to a worn, frayed, and torn section of engine cowling baffling adjacent to the carburetor heat fresh air inlet duct. The pilot/owner of the airplane reported that he was aware of the worn, frayed and torn engine baffling, and he planned to have it replaced at the airplane’s next annual inspection. Given the discovery of the baffling material inside the carburetor air box, it is likely that once carburetor heat was applied, airflow pulled the baffling material into the carburetor inlet, restricting airflow to the carburetor with the resultant loss of power. ## Factual narrative On May 16, 2009, about 1140 Alaska daylight time, a Piper PA-24-250 airplane, N7440P, sustained substantial damage during a forced landing and ditching in Lake Lucille, Wasilla, Alaska, following a loss of engine power. The solo private pilot was not injured. The airplane was being operated as a visual flight rules personal flight under Title 14 Code of Federal Regulations Part 91 when the accident occurred. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated at the Anderson Lake Airport, Wasilla, about 1040. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on May 16, the pilot said that after departing the Anderson Lake Airport, he flew southeast over the Knik Glacier. He said that before returning to the Anderson Lake Airport he did a touch-and-go landing at the Wasilla Airport. After the touch-and-go landing, he climbed the airplane to 1,700 feet msl and flew east toward the Anderson Lake Airport. The pilot reported that while in cruise level flight, he applied full carburetor heat, and all engine power was lost. After completing the emergency procedures for a loss of engine power, he was unable to restart the engine. The pilot said he initially selected a portion of the Parks Highway, a four-lane highway, as an emergency landing site, but vehicle and pedestrian traffic would not allow for a safe landing. He then selected Lake Lucille for a forced landing, which is next to the Parks Highway. The pilot said that he did not lower the airplane’s landing gear, and he selected full flaps during the emergency descent to the lake. He said he ditched the airplane about 100 feet from the north shoreline of the lake. After ditching, the pilot indicated that the airplane initially floated. He said that just before the airplane sank, a small pontoon boat arrived, and took him to shore. The airplane sustained substantial damage to the fuselage during the ditching. The airplane was equipped with a Lycoming O-540-A1D5 engine. An FAA airworthiness inspector from the Anchorage Flight Standards District Office (FSDO), traveled to the accident site on May 19 and examined the wreckage. No preaccident mechanical anomalies were discovered during the examination. During a telephone conversation with the NTSB IIC on May 20, the pilot/owner of the airplane reported that as his mechanic was disassembling the airplane during recovery efforts, he removed the lower engine cowling, and discovered a 4 inch by 2 inch portion of rubberized baffling material lodged inside of the carburetor air box assembly. On May 20, an NTSB investigator traveled to the accident site to document the mechanic’s findings. The NTSB investigator traced the origin of the baffling to a worn and frayed section of engine cowling baffling that was adjacent to the carburetor heat fresh air inlet duct. During a follow up conversation on May 20, the pilot/owner of theairplane reported that he was aware of the worn, frayed and torn engine baffling and he planned to have it replaced in the near future, or at the airplane’s next annual inspection. The closest official weather observation station is at the Wasilla Airport. At 1156, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, calm; visibility, 10 statute miles; clouds and sky condition, 4,900 feet few, 9,000 feet scattered; temperature, 54 degrees F; dew point, 36 degrees F; altimeter, 30.01 inHg. . ## Aircraft - Registration: [N7440P](https://openairdocs.org/aircraft/N7440P), registered now, S/N 24-2629, built 1961 (OpenAirDocs) - Reported make and model: PIPER PA-24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-2629 - Airframe hours: 3347 - Engines: LYCOMING O-540-A1D5 250 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Bruce W. Christie - Registered owner: Bruce W. Christie - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 13, 2008, 32 hours before - Departed: PAWS, Wasilla, AK - Destination: 0AK1, Wasilla, AK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review October 4, 2008; seat: left; flight hours: 1,300 total, 38 in this make and model, 1,250 as pilot in command, 18 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 36 °F - Altimeter: 30.01 inHg - Observed at: IYS, 6 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 20090516025829A](https://openairdocs.org/incident/20090516025829A), May 16, 2009: Piper PA-24-250, Wasilla, AK, Substantial damage. At approximately 1140 adt, pilot was returning to anderson lake strip, Wasilla (0AK1). Pilot reduced power and when carb heat was applied engine died. Pilot… ## Other investigations on N7440P (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 CHI77FEV11](https://openairdocs.org/ntsb/CHI77FEV11), Feb 5, 1977: Piper PA-24 (N7440P), Tolono, IL, substantial damage - [NTSB MKC66F0270](https://openairdocs.org/ntsb/MKC66F0270), Oct 16, 1965: Piper PA-24 (N7440P), Wagner, SD, substantial damage ## Docket (2 files) The files NTSB released with the investigation on March 29, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73853. 1.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 992 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327619&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Telephone Conversation - Pilot (item 2, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327620&FileExtension=.PDF&FileName=Record%20of%20Telephone%20Conversation%20-%20Pilot-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.