# NTSB ANC13LA059: Cessna 175, N7698M, Skwentna, AK, June 29, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 29, 2013, 14:30 local (22:30 UTC) - Place: Skwentna, AK - Coordinates: 61.974445, -151.159729 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.9744&lon=-151.1597&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 2, 2014 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Continental Motors, FAA Anchorage FSDO - NTSB case key (mKey): 87344 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC13LA059 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87344/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87344 - Page: https://openairdocs.org/ntsb/ANC13LA059 ## Probable cause The partial loss of engine power for reasons that could not be determined because the postaccident examination of the engine did not reveal any anomalies that would have precluded normal operation. . ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 175, 3 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072502), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 175, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072502), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 175, 3 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072502), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 175, 3 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072502), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot was departing from a grass-covered runway, and about 100 feet above the ground, the airplane's engine began to lose power. Unable to maintain altitude, the pilot landed the airplane in a swamp; during the landing the airplane nosed over, substantially damaging the wings and vertical stabilizer. The pilot stated that the engine had just been returned to service after a major overhaul, and that it had operated about 3 hours since being returned to service. Examination of the engine revealed that the No. 6 top spark plug ignition wire was inoperative; however, it could not be determined if the damage to the wire was present before the accident. A significant amount of water was found in the gascolator bowl, but due to the position of the airplane in the swamp after the accident, it could not be determined whether or not the water was present at the time of the accident. No other preaccident mechanical malfunctions or failures were noted that would have precluded normal operation. ## Factual narrative On June 29, 2013, about 1430 Alaska daylight time, a Cessna 175 airplane, N7698M, sustained substantial damage during a forced landing, following a partial loss of engine power near Skwentna, Alaska. The airline transport rated pilot and one passenger were not injured. The airplane was registered to, and operated by the pilot as a visual flight rules personal cross-country flight under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane was originating from the Yentna Lodge Strip, destined to Merrill Field, Anchorage, Alaska. According to the pilot, he was departing from the grass-covered runway, and at approximately 100 feet above the ground, the airplane's engine began to lose power. Unable to maintain altitude, the pilot landed the airplane in a swamp, and during the landing the airplane nosed over, substantially damaging the wings and vertical stabilizer. The pilot stated that the engine had just been returned to service after a major overhaul, and that it had operated approximately 3 hours since being returned to service. Examination of the engine logbooks revealed that the engine was removed from the accident airplane on May 4, 2011 at a tachometer time of 209.2 hours. The engine was overhauled on March 1, 2012, and installed in the accident airplane on June 1, 2013 (same tachometer time). At the time of the examination, the tachometer read 212.5 hours. On October 31, 2013, the National Transportation Safety Board investigator-in-charge, along with an investigator from Continental Motors, examined the wreckage at the facilities of Alaska Claims Servies, Wasilla, Alaska. No preaccident anomalies with the airframe were noted. Examination of the engine revealed that manual rotation of the propeller resulted in a spark on each of the spark plugs, in firing order, with the exception of the No. 6 top spark plug. Testing of the No. 6 top spark plug, while attached to a different ignition lead, indicated that the spark plug functioned properly. Testing of the magneto's distributor cap revealed that the ignition tower for the No. 6 top spark plug functioned appropriately. Testing of the No. 6 top spark plug's ignition lead after it was removed and repositioned on the distributor cap revealed that the lead was inoperative. Examination of the lead revealed an area near the distributor cap that was permanently distorted and pinched. There was noticeable buckling and denting on the firewall aft of the magneto distributor cap, but it could not be determined whether the damaged lead was caused by a momentary impingement from the firewall. The carburetor was removed from the engine and was disassembled. Disassembly of the carburetor revealed no internal anomalies or debris. All of the orifices were clear and clean. The fuel inlet screen was removed and no debris was noted. The glass fuel strainer was approximately 1/3 full with an amber colored fluid that appeareddirty. The fluid was collected in a glass jar and water was detected in the sample using water finding paste (SAR-GEL). The fuel strainer screen was dirty but not blocked. It could not be determined if the water in the fuel strainer was present prior to the accident. According to the personnel that recovered the airplane from the accident site, there was at least 30 gallons of aviation fuel removed from the airplane. No other preaccident mechanical malfunctions or failures associated with the engine were noted that would have precluded normal operation. ## Aircraft - Registration: [N7698M](https://openairdocs.org/deregistered/N7698M-2017-09-08), registration cancelled 2017-09-08, S/N 55998, built 1959 (OpenAirDocs) - Reported make and model: CESSNA 175 - Registry model: [Cessna 175](https://openairdocs.org/model/cessna-175) (registry code 2072502) (OpenAirDocs) - Registry engine: [Continental GO-300 series](https://openairdocs.org/engine/continental-go-300-series) (registry code 17024, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 55998 - Airframe hours: 2316 - Engines: CONT MOTOR GO-300 SERIES 175 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 1, 2013, 3 hours before - Departed: Skwentna, AK - Destination: PAMR, Anchorage, AK - Airport: NA, Yentna River Lodge Airstrip ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; airline transport, flight engineer, flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review May 25, 2013; seat: left; restraint: 4-point; flight hours: 12,300 total, 300 in this make and model, 1,500 as pilot in command, 153 in the last 90 days, 25 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 30 statute miles - Lowest ceiling: 3,500 ft overcast - Temperature: 66 °F, dew point 54 °F - Altimeter: 30.02 inHg - Observed at: PASW, 2 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 20130629014739A](https://openairdocs.org/incident/20130629014739A), Jun 29, 2013: Cessna 175, Skwentna, AK, Substantial damage. During climb out after departing yetna lodge, AK, located 10 miles northwest of Skwentna airport (skw), AK, the pilot stated that the aircraft engine began to… ## Docket (2 files) The files NTSB released with the investigation on March 25, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87344. 851 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 532 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410703&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 2, .PDF, 319 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40410704&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-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.