# NTSB CEN21LA338: Aeronca 7AC, N83365, Harrah, OK, July 23, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: July 23, 2021, 15:20 local (20:20 UTC) - Place: Harrah, OK - Coordinates: 35.473353, -97.186388 - Nearby events: https://openairdocs.org/map.md?lat=35.4734&lon=-97.1864&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: Minor injuries - Injuries: 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 103559 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA338 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103559/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103559 - Page: https://openairdocs.org/ntsb/CEN21LA338 ## Probable cause The pilot’s decision to fly the airplane without a carburetor heat control in atmospheric conditions conducive to the development of serious carburetor icing, which resulted in a partial loss of engine power. ## 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: [Aeronca 7AC, 5 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=2110102), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Aeronca 7AC, 9 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2110102), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Aeronca 7AC, 1 case](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=2110102), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/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: [Aeronca 7AC, 4 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=2110102), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) ## Analysis The pilot and pilot-rated-passenger departed in an airplane that did not have a carburetor heat control installed. After takeoff, the engine surged several times and then lost partial power. The pilot completed a forced landing to a field and nosed over; the airplane sustained substantial damage to the horizontal stabilizer and rudder. The atmospheric conditions at the time of the accident were conducive to the development of serious carburetor icing at glide and cruise power. Given the available evidence, it is likely that carburetor ice accumulated during the flight and resulted in a loss of engine power. It is likely that use of carburetor heat would have prevented the accident. ## Factual narrative On July 23, 2021, about 1520 central daylight time, an Aeronca 7AC airplane, N83365, was substantially damaged when it was involved in an accident near Harrah, Oklahoma. The pilot and pilot-rated-passenger sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The pilot-rated-passenger stated that, during the preflight inspection, he and the pilot noted that the carburetor heat control was not installed. They completed a short ground taxi and engine runup with no anomalies noted. Shortly after takeoff, the engine rpm surged then decreased such that the airplane was unable to maintain altitude. The pilot made a forced landing to a field and the airplane nosed over. The passenger reported that he had experienced carburetor ice many times in the past and believed that the loss of engine power was the result of carburetor ice. The pilot, who was also the airplane owner, stated that, about 150 ft above ground level after takeoff, the airplane was sluggish and the engine surged between 2,000 and 2,400 rpm, then experienced a loss of power. They made a forced landing to a field of tall grass and soft soil and the airplane nosed over. The pilot reported that there were no mechanical malfunctions or anomalies that would have precluded normal operation. The pilot provided photos that showed substantial damage to the horizontal stabilizer and rudder. The atmospheric conditions at the time of the accident were conducive to the development of serious carburetor icing at glide and cruise power. Postaccident photos of the airplane revealed that the carburetor heat control was missing. ## Aircraft - Registration: [N83365](https://openairdocs.org/deregistered/N83365-2023-06-08), registration cancelled 2023-06-08, S/N 7AC-2032, built 1946 (OpenAirDocs) - Reported make and model: AERONCA 7AC - Registry model: [Aeronca 7AC](https://openairdocs.org/model/aeronca-7ac) (registry code 2110102) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7AC-2032 - Year built: 1946 - Airframe hours: 4240 - Engines: CONT MOTOR O-200 65 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Jonathan Wise & Associates Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 23, 2021 - Airport: 1OL2, Steciak Strip, runway 17/35, 2,375 × 60 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: minor; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, waiver time limited special; last flight review August 1, 2021; seat: rear; restraint: lap only; flight hours: 2,475 total, 165 in this make and model, 2,242 as pilot in command, 130 in the last 90 days, 40 in the last 30 days, 0 in the last 24 hours - Pilot-rated passenger; injuries: minor; airplane ratings: single-engine land; seat: front; restraint: lap only ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 12 knots - Visibility: 10 statute miles - Temperature: 90 °F, dew point 68 °F - Altimeter: 30.05 inHg - Observed at: KSNL, 14 nm away - METAR: METAR KSNL 232115Z AUTO 18012KT 10SM SCT040 SCT049 SCT060 32/20 A3005 RMK AO2 T03230199= ## 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 20210723020409A](https://openairdocs.org/incident/20210723020409A), Jul 23, 2021: Aeronca 7AC, Harrah, OK, Substantial damage. Shortly after take off, the engine started to surge. It would lose power, then gain power. The situation progressively became worse. The pilot did not know if… ## Other investigations on N83365 (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 DEN07CA099](https://openairdocs.org/ntsb/DEN07CA099), Jun 9, 2007: Aeronca 7AC (N83365), Erie, CO, substantial damage. Probable cause: The student pilot's failure to maintain direction control during the landing roll. ## Docket (3 files) The files NTSB released with the investigation on November 7, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103559. 12.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 10.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13014389&FileExtension=pdf&FileName=6120%20-%20pilot%20plus%20email_Redacted-Rel.pdf - Correspondence - pilot-rated-passenger (item 2, PDF, 2 pages, 157 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13013435&FileExtension=pdf&FileName=ROC%20-%20Brett%20Baker%20Passenger_Redacted-Rel.pdf - Photos (item 3, PDF, 3 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13023180&FileExtension=pdf&FileName=Photos-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.