# NTSB CEN15LA217: Cessna 150F, N8558G, Neillsville, WI, May 2, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 2, 2015, 09:00 local (14:00 UTC) - Place: Neillsville, WI - Coordinates: 44.575279, -90.506668 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.5753&lon=-90.5067&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report November 29, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 91123 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA217 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91123/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91123 - Page: https://openairdocs.org/ntsb/CEN15LA217 ## Probable cause A partial loss of engine power for reasons that could not be determined because a postaccident examination of the airframe and 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 150F, 6 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2071814), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna 150F, 7 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=2071814), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/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 (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 150F, 8 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071814), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 150F, 39 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071814), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot reported that the engine start and run-up were normal. About 20 minutes after takeoff for the personal cross-country flight, the engine power decreased to idle. The pilot applied the carburetor heat, and the engine regained cruise power. About 2 minutes later, he turned the carburetor heat off. The engine continued to produce cruise power for about 4 minutes before it again decreased to idle. The pilot reapplied carburetor heat, and the engine power increased for about 1 minute before dropping back to idle. The pilot cycled the carburetor heat and verified the position of the engine and fuel controls, but he was unable to regain engine power. The airplane contacted trees shortly after touching down in a field. A postaccident examination of the airplane and engine did not reveal any mechanical failures or malfunctions that would have precluded normal operation. Although the weather conditions were conducive for the formation of carburetor ice at glide power settings, the engine was set at cruise power when the initial loss of engine power occurred, and the application of carburetor heat did not regain the engine power. The airplane departed with about 10 gallons of fuel onboard. The flight lasted about 40 minutes, and the airplane consumes about 6 gallons per hour, which would have left about 6 gallons of fuel on board at the time of the accident, 3.5 gallons of which were unusable. The postaccident examination revealed that fuel was onboard the airplane. The investigation could not determine the reason for the loss of engine power. ## Factual narrative On May 2, 2015, at 0900 central daylight time, a Cessna 150F, N8558G, collided with trees during an off airport forced landing in Neillsville, Wisconsin, following a loss of engine power. The private pilot, sole occupant, received minor injuries. The airplane was substantially damaged. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from the Wausau Downtown Airport (AUW), Wausau, Wisconsin about 0820. The intended destination was the Neillsville Municipal Airport (VIQ), Neillsville, Wisconsin.The pilot reported that the engine start and run-up were normal. He sat on the ground waiting for other aircraft traffic to clear then he taxied and took off without incident. About 20 minutes after takeoff, the engine power decreased to idle in about 1 second. The pilot applied the carburetor heat and the engine regained cruise power. About two minutes later, he turned the carburetor heat off. The engine continued to produce cruise power for about four minutes when it once again decreased to idle. He once again applied carburetor heat and the engine power momentarily increased to full power before dropping back to idle. The pilot cycled the carburetor heat, and verified the position of the throttle, magnetos, fuel selector, engine primer, and mixture with no change in the engine power from idle. The pilot located a field which contained downward sloping terrain in which to land. The pilot cleared power lines that bordered the field. The airplane floated in ground effect and it came to an abrupt stop up against trees shortly after the main gear touched down. A postaccident inspection of the airframe and engine by a Federal Aviation Administration airworthiness inspector did not reveal any mechanical failure/malfunction that would have prevented normal operation. The left fuel tank contained about ¼ tank of fuel and the right tank contained about 1/8 tank of fuel when the airplane was first examined after the accident. The FAA inspector stated the fuel system was intact. The pilot stated that there was a strong odor of fuel in the area after the accident. The airplane held 26 gallons of fuel with 3.5 gallons being unusable. The pilot reported he departed with about 10 gallons of fuel on board. The fuel consumption for the airplane is about 6 gallons per hour. The temperature and dewpoint reported at the Marshfield Municipal Airport (MFI), Marshfield, Wisconsin, located about 3 miles from the accident site at 0854 were 17 degrees Celsius (63 Fahrenheit) and 4 degrees Celsius (39 Fahrenheit) respectively. According to the FAA SAIB CE-09-35 "Carburetor Icing Prevention" chart, serious icing at glide power was a probability. A risk of carburetor icing at cruise power was not probable according to the bulletin. ## Aircraft - Registration: [N8558G](https://openairdocs.org/deregistered/N8558G-2016-01-04), registration cancelled 2016-01-04, S/N 15062658, built 1966 (OpenAirDocs) - Reported make and model: CESSNA 150F - Registry model: [Cessna 150F](https://openairdocs.org/model/cessna-150f) (registry code 2071814) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15062658 - Year built: 1966 - Airframe hours: 7391 - Engines: CONT MOTOR O-200 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 21, 2014 - Departed: AUW, Wausau, WI - Destination: VIQ, Neillsville, WI - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review July 21, 2014; seat: left; restraint: lap only; flight hours: 475 total, 370 in this make and model, 475 as pilot in command, 25 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 39 °F - Altimeter: 29.98 inHg - Observed at: MFI, 3 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 20150502006379A](https://openairdocs.org/incident/20150502006379A), May 2, 2015: Cessna 150F, Neillsville, WI, Substantial damage. While cruising at 2800 ft. enroute from wausau, WI. (Auw) to Neillsville, WI. (Viq) engine RPM went from 2400 RPM to idle. Carb heat was applied and RPM… ## Other investigations on N8558G (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 MKC67D0440](https://openairdocs.org/ntsb/MKC67D0440), Feb 6, 1967: Cessna 150 (N8558G), St. Charles, MO, substantial damage ## Docket (3 files) The files NTSB released with the investigation on August 25, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91123. 2.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443716&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation (item 2, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443717&FileExtension=.PDF&FileName=Record%20of%20Conversation-Master.PDF - Carburetor Icing Probability Chart (item 3, .PDF, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40443718&FileExtension=.PDF&FileName=Carburetor%20Icing%20Probability%20Chart-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.