# NTSB GAA17CA306: Cessna 150, N60579, Zepp, VA, May 21, 2017 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: May 21, 2017, 09:45 local (13:45 UTC) - Place: Zepp, VA - Coordinates: 39.039722, -78.555831 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.0397&lon=-78.5558&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report January 23, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 95249 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA306 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95249/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95249 - Page: https://openairdocs.org/ntsb/GAA17CA306 ## Probable cause A partial loss of engine power due to the formation of carburetor icing, which resulted from the student pilot’s failure to apply carburetor heat and the flight instructor’s delayed response in applying carburetor heat while operating in conditions conducive to carburetor icing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=2071820), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Student/instructed pilot (probable cause); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=2071820), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=2071820), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Student/instructed pilot (probable cause); cases with it: [Cessna 150J, 3 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=2071820), [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 150J, 1 case](https://openairdocs.org/ntsb-findings/01023020/cases.md?model=2071820), [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=2071820), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=2071820), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna 150J, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2071820), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Enroute-cruise: Controlled flight into terr/obj (CFIT)](https://openairdocs.org/ntsb-events/120); cases with it: [Cessna 150J, 1 case](https://openairdocs.org/ntsb-events/120/sequence.md?model=2071820), [All aircraft, 1,074 cases](https://openairdocs.org/ntsb-events/120/sequence.md) ## Analysis The flight instructor reported that, during a long cross-country flight, they encountered deteriorating weather conditions, and to remain visual flight rules, he altered course and destination. En route and while approaching a ridge line, he "noticed that [the airplane's] airspeed started to drop toward 65 miles an hour." He added that "[he] thought that maybe [the airplane was] picking up carburetor ice and [he] reached for the carburetor heat and pulled it out." The student pilot reported that, after the flight instructor stated, "watch your airspeed," he looked at the rpm gauge and noted that it was indicating 1,800 to 1,900 rpm. He added that the flight instructor took over the flight controls and that the airplane then impacted the top of a ridge. The airplane sustained substantial damage to the right wing. Atmospheric conditions reported at the time of the accident around the accident site were conducive to serious icing at cruise power. It is likely that carburetor ice accumulated due to the student pilot's failure to apply carburetor heat and the flight instructor's delayed application of carburetor heat, which resulted in a partial loss of engine power. ## Factual narrative The flight instructor reported that, during a long cross-country flight, they encountered deteriorating weather conditions, and in order to remain VFR, altered course and destination. En route, while approaching a ridge line, he "noticed that [the airplane's] airspeed started to drop toward 65 miles an hour". He added that "[he] thought that maybe [they] were picking up carburetor ice and [he] reached for the carburetor heat and pulled it out". The student pilot reported that after the flight instructor stated, "watch your airspeed", he looked at the Revolutions Per Minute (RPM) gauge and noted that it was indicating 1800-1900 RPM. He added that, the flight instructor took over the flight controls and the airplane impacted the top of the ridge. A review of multiple weather observation stations, located around the four corners of the accident site, revealed similar conditions, temperature 55°F, and dew point 43°F. Review of the Federal Aviation Administration Carburetor Icing Chart for the given temperature and dew point revealed that the conditions were conducive to "serious icing at cruise power". (For more information see Special Airworthiness Information Bulletin CE-09-35 in the public docket.) The airplane sustained substantial damage to the right wing. ## Aircraft - Registration: [N60579](https://openairdocs.org/deregistered/N60579-2018-06-27), registration cancelled 2018-06-27, S/N 15070419, built 1969 (OpenAirDocs) - Reported make and model: CESSNA 150 (J) - Registry model: [Cessna 150J](https://openairdocs.org/model/cessna-150j) (registry code 2071820) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 15070419 - Year built: 1969 - Airframe hours: 3972 - Engines: CONT MOTOR O-200 100 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 14, 2017 - Departed: CBE, CUMBERLAND, WV - Destination: 8W2, NEW MARKET, VA - Equipment: Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 71; injuries: minor; airline transport, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review August 1, 2016; seat: right; restraint: 4-point; flight hours: 28,250 total, 70 in this make and model, 26,750 as pilot in command, 41.7 in the last 90 days, 8.8 in the last 30 days, 3.7 in the last 24 hours - Student pilot; age 28; injuries: none; student; medical: class 3, without waivers/limitations; seat: left; flight hours: 31.6 total, 31.6 in this make and model, 14 as pilot in command, 14.1 in the last 90 days, 6 in the last 30 days, 3.7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 120° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 3,300 ft overcast - Temperature: 55 °F, dew point 43 °F - Altimeter: 30.29 inHg - Observed at: KOKV, 20 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 20170521018959A](https://openairdocs.org/incident/20170521018959A), May 21, 2017: Cessna 150J, Warensville, WV, Destroyed. Instructor and student were delivering an aircraft after purchasing it. Weather was deteriorating. Aircraft failed to clear mountain top. Weather was ovc:08 24… ## Docket (4 files) The files NTSB released with the investigation on December 5, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95249. 1.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 842 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458559&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Flight Instructor Statement (item 2, .PDF, 433 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458560&FileExtension=.PDF&FileName=Flight%20Instructor%20Statement-Master.PDF - Special Airworthiness Information Bulletin CE-09-35 (item 3, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458561&FileExtension=.PDF&FileName=Special%20Airworthiness%20Information%20Bulletin%20CE-09-35-Master.PDF - Accident Photo (Courtesy of FAA) (item 4, .PDF, 1 photo, 309 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40458562&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20FAA)-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.