# NTSB CEN21LA047: Ercoupe 415, N331BW, Ardmore, OK, November 7, 2020 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: November 7, 2020, 08:30 local (14:30 UTC) - Place: Ardmore, OK · 506 Concord Road, Ardmore, OK - Coordinates: 34.127751, -97.063227 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.1278&lon=-97.0632&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Serious injuries - Injuries: 1 serious, 2 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA Will Rogers FSDO - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 102256 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102256/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102256 - Page: https://openairdocs.org/ntsb/CEN21LA047 ## Probable cause The pilot’s improper decision to takeoff with 3 persons in a 2-place airplane and over maximum gross weight, and his failure to apply carburetor heat when the airplane’s engine experienced carburetor ice and a partial loss of power. ## 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 · Pilot (probable cause); cases with it: [Ercoupe 415-C, 2 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=0420322), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Ercoupe 415-C, 2 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=0420322), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) - [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: [Ercoupe 415-C, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=0420322), [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. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220); cases with it: [Ercoupe 415-C, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=0420322), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Ercoupe 415-C, 2 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=0420322), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Ercoupe 415-C, 6 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=0420322), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Maneuvering-low-alt flying: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Ercoupe 415-C, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=0420322), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Ercoupe 415-C, 7 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=0420322), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Ercoupe 415-C, 6 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=0420322), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot was performing a local flight with two passengers onboard the two-seat airplane. After flying two passes over a house, the pilot felt a “slight shudder” and thought the airplane had flown through its own propeller wash. The engine then started to vibrate, and the pilot was not able to control the vibration by adjusting the throttle. The pilot set the airplane up in a glide configuration at which time the airplane banked to the left. The pilot applied full right aileron control, but it did not stop the left turn. The pilot was attempting to land the airplane in a field when it contacted a tree and came to rest inverted. A postaccident examination revealed no preimpact mechanical malfunctions or failures with the airframe, including the flight controls, and engine that would have precluded normal operation. It was determined that the airplane was 48 pounds over its maximum gross weight when the pilot started the engine. A review of local area meteorological data showed that at the time of the accident, the airplane was likely operating in conditions conducive to the formation of serious icing conditions (at cruise power). The pilot reported he did not apply the carburetor heat when the engine began to lose power. It is likely the engine sustained a partial loss of engine power in flight due to the formation of carburetor icing, which resulted in the attempted forced landing. ## Factual narrative On November 7, 2020, about 0830 central standard time, an ERCO Ercoupe 415-C airplane, N331BW, sustained substantial damage when it was involved in an accident near Ardmore, Oklahoma. The commercial pilot sustained serious injuries and the two passengers sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The purpose of the flight was for the pilot to take the two passengers in the two-seat airplane on a local flight to photograph a home. The pilot reported the airplane departed with a full fuel load. The pilot was in the left seat while the two passengers shared the right seat . Both seats were equipped with lap belts. After the completing two passes by the house, the pilot felt a “slight shudder” and he announced to the passengers that he thought they were flying through the airplane’s own propeller wash. Immediately after that, the engine started “vibrating so bad” that the pilot thought the engine was going to separate from the airframe. The pilot attempted to control the vibration by adjusting the throttle to no avail. He did not apply carburetor heat. The pilot then set the airplane up in a glide configuration at which time the airplane banked to the left. The pilot applied full right aileron control, but it did not stop the left turn. The pilot was attempting to land the airplane in a field when it contacted a tree and came to rest inverted. The airplane sustained substantial damage to the fuselage, both wings, and the empennage. A postaccident examination of the engine and airframe, including the flight controls, revealed no preimpact mechanical malfunctions or failures with the airframe and engine that would have precluded normal operation. A review of local area meteorological data showed that at the time of the accident, the airplane was likely operating in conditions conducive to the formation of serious icing conditions (at cruise power) per the Federal Aviation Administration (FAA) Special Airworthiness Information Bulletin CE-09-35 Carburetor Icing Prevention. A review of weight and balance data showed that the airplane was 48 pounds over the maximum weight at the time of engine start. According to ERCO Ercoupe Information Letter Number 2, the model 415-C does not employ a flight manual, and none is available. According to FAA Type Certificate Data Sheet A-718 for the airplane, it is limited to two seats, but the data sheet does not address the topic of two passengers sharing a single seat together. The FAA has issued a clarification on the interpretation of the seat belt and seating requirements for general aviation flights and states in part: This clarification states that the use of a seat belt and/or seat by more than one occupant is permitted only if the seat usage conforms to the limitations contained in the approved portion of the Airplane Flight Manual (AFM). In addition, before multiple occupants use the same seat and/or seat belt, if the pertinentinformation is available, the pilot in command (PIC) must also check whether: The seat belt is approved and rated for such use; and the structural strength requirements for the seat are not exceeded. This clarification also emphasizes that, because it is safer for each individual person to have his or her own seat and seat belt, whenever possible, each person onboard an aircraft should voluntarily be seated in a separate seat and be restrained by a separate seat belt. ## Aircraft - Registration: [N331BW](https://openairdocs.org/deregistered/N331BW-2021-12-11), registration cancelled 2021-12-11, S/N 2091, built 1946 (OpenAirDocs) - Reported make and model: ERCOUPE 415 (C) - Registry model: [Ercoupe 415-C](https://openairdocs.org/model/ercoupe-415-c) (registry code 0420322) (OpenAirDocs) - Registry engine: [Continental A&C75 series](https://openairdocs.org/engine/continental-a-c75-series) (registry code 17005, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2091 - Year built: 1946 - Airframe hours: 1881.07 - Engines: Continental Motors C-85-12 85 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 29, 2020, 2.72 hours before - Departed: 1FO, Ardmore, OK - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 78; injuries: serious; sport pilot, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; last flight review April 23, 2019; seat: left; restraint: lap only; flight hours: 2,405 total, 255 in this make and model, 1,992 as pilot in command, 8.4 in the last 90 days, 3.8 in the last 30 days, 0.5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 52 °F - Altimeter: 30.13 inHg - Observed at: K1F0, 3 nm away - METAR: K1F0 071415Z AUTO 14003KT 10SM CLR 13/11 A3013 RMK AO2 T01300111 ## 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 20201107021689A](https://openairdocs.org/incident/20201107021689A), Nov 7, 2020: Ercoupe 415-C, Ardmore, OK, Destroyed. On November 7 2020, approximately 08:06 central daylight time, a 1946 Ercoupe, N331BW, operated by [privacy data omitted], under 14 crf part 91, was destroyed… ## Docket (4 files) The files NTSB released with the investigation on June 6, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102256. 28.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13081488&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20Redacted-Rel.pdf - Accident photographs (item 2, PDF, 10 pages, 9.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13081793&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf - Additional documents (item 3, PDF, 18 pages, 12.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13081498&FileExtension=pdf&FileName=Additional%20Documents%20Redacted-Rel.pdf - Additional statements (item 4, PDF, 5 pages, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13081803&FileExtension=pdf&FileName=Additional%20Statements%20Redacted-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.