# NTSB ERA16LA068: Mccorkle Robert B Rans S-12 Airaile, N6202N, Benton, TN, December 12, 2015 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: December 12, 2015, 14:40 local (19:40 UTC) - Place: Benton, TN - Coordinates: 35.224166, -84.584724 - Nearby events: https://openairdocs.org/map.md?lat=35.2242&lon=-84.5847&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report May 9, 2018 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 92442 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA16LA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92442/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92442 - Page: https://openairdocs.org/ntsb/ERA16LA068 ## Probable cause The pilot's failure to maintain airplane control during the initial climb, which resulted in the airplane exceeding its critical angle of attack and an aerodynamic stall/spin. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mccorkle Robert B RANS S-12 AIRAILE, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056224P), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Mccorkle Robert B RANS S-12 AIRAILE, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=056224P), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Mccorkle Robert B RANS S-12 AIRAILE, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056224P), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Initial climb: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Mccorkle Robert B RANS S-12 AIRAILE, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=056224P), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Initial climb: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Mccorkle Robert B RANS S-12 AIRAILE, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056224P), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The sport pilot of the experimental, amateur-built airplane was the last to takeoff in a group of three airplanes. After takeoff, the airplane entered a steep climb, banked sharply left, and then descended rapidly in a manner consistent with an aerodynamic stall and spin. Examination of the airplane did not reveal evidence of any preexisting mechanical anomalies that would have precluded normal operation. It is likely that, during the initial climb, the pilot failed to maintain control of the airplane, which resulted in the exceedance of the airplane's critical angle of attack and an aerodynamic stall/spin. Although the pilot had coronary artery disease, and he was taking clozapine, a drug that can cause seizures or cardiac arrest, it could not be determined whether the pilot was impaired or incapacitated at the time of the accident. ## Factual narrative On December 12, 2015, about 1440 eastern standard time, an experimental, amateur-built RANS S-12 Airaile airplane, N6202N, was substantially damaged when it impacted the ground shortly after takeoff from Chilhowee Gilderport (92A), Benton, Tennessee. The sport pilot was fatally injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the flight to a private airstrip in Athens, Tennessee.According to witnesses, the airplane was the third in a group of three to take off from runway 21 at 92A. Witnesses noted that, after the takeoff, the airplane made a "rapid" or "steep" climb at the top of which it began a left turn. One witness noted that the airplane then entered a "steep wingover-like 180° turn reversing to the north." The airplane was then "in a low energy state," about 150 ft above ground level (agl) at a high rate of descent with "the left wing [then] lowering in what can only be described as a 1/2- to 3/4-turn spin, impacting the ground with the left wing and nose." Another witness noted that the airplane "appeared to stall, hovered for a split second and twisted in a nose dive into [a] sod field." A third witness stated that the airplane was in a left bank of about 70° to 80° and subsequently "descended rapidly then 'nosed over' and impacted the ground in a near vertical attitude." A fourth witness, who was inside at the time, stated, "I heard the crash; the sound of the engine was loud and even right up to the moment of impact." The accident site was located in an open grass field about 360 ft southeast of runway 21. According to a local law enforcement incident report, the airplane impacted terrain inverted and was subsequently righted by first responders. A Federal Aviation Administration (FAA) inspector's examination of the airplane did not reveal evidence of any preexisting mechanical anomalies that would have precluded normal operation. Photographs of the airplane showed crush damage to the forward section of the fuselage and the leading edges of both wings. All major flight control surfaces remained attached. The engine remained attached to the airframe. The propeller hub remained attached to the engine. Two of the wooden propeller blades were fragmented near the propeller hub, and one blade fragmented near the tip. According to FAA airman records, the pilot held a sport pilot certificate. He also held a light sport aircraft repairman certificate that was limited to N4288S, a Quad City Challenger II, serial number GC6151954. The pilot did not hold a medical certificate nor was he required to for the accident flight. The pilot's logbook was not located. According to FAA airworthiness records, the two-seat, single-engine airplane was manufactured in 1992. It was powered by a 100-horsepower Bombardier Rotax 912 engine. The airplane's airframe and enginelogbooks were not located. According to a specifications sheet provided on the kit manufacturer's (Rans Aircraft) website, the airplane's aerodynamic stall speed with flaps retracted was 42 mph and with flaps extended was 35 mph. The airplane's flap setting at the time of the accident was not determined. A witness at the airport reported that the wind was from the south at 8 to10 miles per hour. The weather conditions reported at McMinn County Airport (MMI), Athens, Tennessee, about 10 nautical miles north of the accident site, included wind from 230° at 7 knots, visibility 10 statute miles, few clouds at 5,000 ft agl, temperature 21°C, and dew point 13°C. The Center for Forensic Medicine, Office of the Medical Examiner, Nashville, Tennessee, performed an autopsy on the pilot. The autopsy report noted the cause of death as "multiple blunt force injuries." The autopsy also revealed that the pilot had significant coronary artery disease with 70-80% stenosis of the left anterior descending artery and 50-60% stenosis of the right coronary artery. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on samples from the pilot. The testing identified clozapine, an antipsychotic medication known to increase the risk of a number of medical conditions including seizures and death, and propranolol, a non-impairing medication most often used to treat hypertension. ## Aircraft - Registration: [N6202N](https://openairdocs.org/deregistered/N6202N-2022-07-30), registration cancelled 2022-07-30, S/N 0992285 (OpenAirDocs) - Reported make and model: MCCORKLE ROBERT B RANS S-12 AIRAILE - Registry model: [Mccorkle Robert B RANS S-12 AIRAILE](https://openairdocs.org/model/mccorkle-robert-b-rans-s-12-airaile) (registry code 056224P) (OpenAirDocs) - Registry engine: [Bombardier ROTAX (ALL)](https://openairdocs.org/engine/bombardier-rotax-all) (registry code 09050, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 0992285 - Year built: 1992 - Engines: ROTAX 912 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Departed: 92A, Benton, TN - Destination: NONE, Athens, TN - Airport: 92A, Chilhowee Gliderport, runway 21, 2,600 × 200 ft, grass/turf - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: fatal; sport pilot; airplane ratings: single-engine land; medical: sport pilot; seat: left; toxicology performed ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 55 °F - Altimeter: 30.20 inHg - Observed at: MMI, 10 nm away ## Docket (8 files) The files NTSB released with the investigation on April 25, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92442. 2.7 MB in all. - Witness Statements (item 1, .PDF, 791 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462451&FileExtension=.PDF&FileName=Witness%20Statements-Master.PDF - NTSB Memorandum for Record - FAA Accident Report (item 2, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462453&FileExtension=.PDF&FileName=NTSB%20Memorandum%20for%20Record%20-%20FAA%20Accident%20Report-Master.PDF - NTSB Memorandum for Record - Local Law Enforcement Report (item 3, .PDF, 58 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462452&FileExtension=.PDF&FileName=NTSB%20Memorandum%20for%20Record%20-%20Local%20Law%20Enforcement%20Report-Master.PDF - Rans S 12 Specification Sheet (item 4, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462454&FileExtension=.PDF&FileName=Rans%20S%2012%20Specification%20Sheet-Master.PDF - Photo Array (item 5, .PDF, 4 photos, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462455&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF - Toxicological Report (item 6, .PDF, 192 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462456&FileExtension=.PDF&FileName=Toxicological%20Report-Master.PDF - Medical Factual Report (item 7, .PDF, 267 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462457&FileExtension=.PDF&FileName=Medical%20Factual%20Report-Master.PDF - Routine Hourly Weather Reports (item 8, .PDF, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40462458&FileExtension=.PDF&FileName=Routine%20Hourly%20Weather%20Reports-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.