# NTSB CEN21LA381: Cessna 150M, N66748, Wadsworth, OH, August 11, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 11, 2021, 10:00 local (14:00 UTC) - Place: Wadsworth, OH - Coordinates: 41.03, -81.8 - Nearby events: https://openairdocs.org/map.md?lat=41.0300&lon=-81.8000&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 103745 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA381 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103745/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103745 - Page: https://openairdocs.org/ntsb/CEN21LA381 ## Probable cause A partial loss of engine power due to carburetor icing and the pilot’s failure to apply carburetor heat when the power loss occurred. ## 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: [Cessna 150M, 9 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=2071830), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 150M, 5 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=2071830), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Ice/rain protection system: intake anti-ice, deice](https://openairdocs.org/ntsb-findings/01023020): Aircraft › Aircraft systems · Not used/operated (probable cause); cases with it: [Cessna 150M, 2 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md?model=2071830), [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Cessna 150M, 7 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=2071830), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 150M, 14 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071830), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 150M, 14 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071830), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 150M, 39 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2071830), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, shortly after takeoff, she noticed that the airplane was not climbing normally and heard the stall warning horn. The pilot then noticed the engine speed was rapidly decreasing from 2,500 to 1,500 rpm. The pilot established the airplane’s best glide speed and prepared for a forced landing to a corn field. She did not apply carburetor heat. After touchdown, the airplane nosed over, resulting in substantial damage to the fuselage, vertical stabilizer, and rudder. A postaccident examination of the engine revealed low compression on the No.1 cylinder, but, after staking the valves, compression increased with no leaking past the valves. Also, the airplane’s most recent annual inspection was completed 4 days before the accident with normal compressions noted. Thus, the low compression during the postaccident examination was likely a result of the accident and the airplane remaining in an inverted position in the field for about 4 days after the accident. When the temperature and dew point of the area surrounding the accident site were entered into a carburetor icing probability chart, the result was in the “moderate icing – cruise power” and “serious icing – glide power” category. When the pilot was asked how the carburetor heat was checked, she stated that she turned it on, saw a drop in engine rpm and immediately turned it off. Thus, the loss of engine power was likely due to carburetor icing that accumulated before and during the takeoff, and the pilot’s failure to apply carburetor heat when the engine speed began to decrease. The momentary application of carburetor heat before takeoff was likely not sufficient to reduce or eliminate the ice buildup. ## Factual narrative On August 10, 2021, about 1000 eastern daylight time, a Cessna 150, N66748, sustained substantial damage when it was involved in an accident near Wadsworth Municipal Airport, Wadsworth, Ohio. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, after she taxied to runway 21, she used the airplane’s checklist to perform an engine run-up, which included checking the magnetos and carburetor heat. Afterward, she taxied the airplane into position on the runway, held the brakes, and advanced the throttle to full power before releasing the brakes to initiate the takeoff. The pilot stated that, shortly after takeoff, she noticed that the airplane was not climbing normally and heard the stall warning horn. She then noticed the that the engine speed had rapidly decreased from 2,500 to 1,500 rpm and was continuing to decrease. The pilot stated that, due to the airplane’s low altitude, she had time only to establish the airplane’s best glide speed and prepare for forced landing to a corn field. After touchdown, the airplane nosed over, resulting in substantial damage to the fuselage, vertical stabilizer, and rudder. The airplane remained inverted in the field for about 4 days prior to recovery. Postaccident examination of the engine revealed low compression on the No.1 cylinder. Further examination with a borescope found a small amount of carbon and lead fouling on the piston and valves. The valve cover was removed, and all valves were observed moving without restriction. After staking the valves, compression increased from 12/80 to 60/80 with no leaking past the valves. (At the time of the engine’s most recent 100 hour and annual inspection, which was 4 days before the accident, the compression in the No.1 cylinder was 78/80.) All spark plugs were removed and tested; all produced a strong blue spark. When the temperature (20°C) and dew point (17°C) that were present in the area surrounding the accident site were entered into a carburetor icing probability chart, the result was in the “moderate icing – cruise power” and “serious icing – descent power” category, as shown in the figure below. The Cessna 150 pilot’s operating handbook stated, “carburetor ice, as evidenced by an unexplained drop in RPM, can be removed by application of full carburetor heat.” Figure . Carburetor icing probability chart (Source: AAIB). ## Aircraft - Registration: [N66748](https://openairdocs.org/aircraft/N66748), registered now, S/N 15076249, built 1974 (OpenAirDocs) - Reported make and model: CESSNA 150M - Registry model: [Cessna 150M](https://openairdocs.org/model/cessna-150m) (registry code 2071830) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15076249 - Year built: 1974 - Airframe hours: 9244.7 - Engines: Continental Motors O200 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Skypark Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 6, 2021, 11.2 hours before - Destination: Same as departure - Airport: 15G, Weltzien Skypark, runway 03/21, 2,410 × 37 ft, asphalt - Equipment: Stall warning system, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review June 14, 2021; seat: left; restraint: 3-point; flight hours: 358 total, 110 in this make and model, 220 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 15,000 ft broken - Temperature: 68 °F, dew point 63 °F - Altimeter: 30.01 inHg - Observed at: KBJJ, 9.6 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 20210811014249A](https://openairdocs.org/incident/20210811014249A), Aug 11, 2021: Cessna 150M, Wadsworth, OH, Substantial damage. Aircraft departed southbound from 15G on runway 21. Immediately after takeoff pilot noticed aircraft was not climbing normally and stall warning horn sounded.… ## Other investigations on N66748 (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 NYC04LA030](https://openairdocs.org/ntsb/NYC04LA030), Nov 9, 2003: Cessna 150M (N66748), Wooster, OH, minor damage. Probable cause: The inadequate visual lookout of the student pilot of the Cessna 150M, which resulted in an on-ground collision with a Cessna 150K that was taking off. ## Docket (6 files) The files NTSB released with the investigation on December 12, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103745. 8.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12830474&FileExtension=pdf&FileName=Accident%20Report_Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 1 page, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14820060&FileExtension=pdf&FileName=Pilot%20Interview-Rel.pdf - Maintenance records (item 3, PDF, 1 page, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12830575&FileExtension=pdf&FileName=Maintenance%20Records_Redacted-Rel.pdf - Photos (item 4, PDF, 2 pages, 388 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12830585&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf - Engine examination summary (item 5, PDF, 2 pages, 179 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12850061&FileExtension=pdf&FileName=Engine%20Examination%20Notes-Rel.pdf - POH excerpt - carburetor icing (item 6, PDF, 2 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14109401&FileExtension=pdf&FileName=POH%20Excerpt-Rel.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.