# NTSB CEN18LA157: Hartline J Bon Hartline Kitfox III, N73BH, Marathon, TX, May 2, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 2, 2018, 11:00 local (16:00 UTC) - Place: Marathon, TX - Coordinates: 33.229591, -97.589981 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2296&lon=-97.5900&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report June 3, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 97161 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18LA157 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97161/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97161 - Page: https://openairdocs.org/ntsb/CEN18LA157 ## Probable cause The failure of the flaperon hinge attachment point during takeoff, which resulted in a loss of airplane control. Contributing to the accident was the lack of reinforcement of the hinge attachment point in accordance with the manufacturer’s service bulletin. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Owner/builder (probable cause); cases with it: [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot and the passenger were departing on a local personal flight in the experimental amateur-built airplane. The pilot indicated that, during the takeoff climb, about 15 ft above the ground, the airplane violently rolled to the right. He applied full aileron and rudder opposite the direction of the roll, but the airplane continued to roll to the right, struck the ground with the right wing, and then impacted a tree. Postaccident examination of the airplane revealed that three of the four hinges connecting the right flaperon hanger rib were loose. The wooden material of the flaperon was found dry rotted where the hinges connected. The airplane had been flown about 3 hours in the 11 months before the accident. The airplane kit manufacturer had issued a service bulletin in 1991 that identified flaperon hanger rib failures on the model of the accident airplane. The service bulletin recommended the addition of an aluminum reinforcement on each flaperon hanger rib end. The accident airplane did not have the reinforcement installed and thus did not have the benefit of additional reinforcement in the attachment point area of the hinges. ## Factual narrative On May 2, 2018, about 1100 central daylight time, an experimental, amateur-built Kitfox III airplane, N73BH, was substantially substantial damaged during a forced landing after takeoff from the Stovall Ranch Airport (6TX9), Marathon, Texas. The airline transport pilot and one passenger sustained minor injuries. The airplane was privately owned and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed throughout the area and no flight plan was filed for the flight. The local flight was originating at the time of the accident. The pilot reported that during takeoff, about 15 ft above the ground, the airplane rolled violently to the right. He applied full aileron and rudder opposite the direction of the roll, but the airplane continued to roll to the right. The airplane struck the ground with the right wing and then impacted a mesquite tree. Examination of the wreckage after the accident revealed that 3 of the 4 hinges connecting the right flaperon hangar rib were loose. The wooden (spruce) material of the flaperon appeared to by dry rotted where the hinges attached. According to records provided by the owner, the airplane had last flown about 6 months prior to the accident flight. Records showed that the airplane had about 3 hours of flight time since its most recent conditional airworthiness inspection which was performed on May 23, 2017. Denny Aerocraft Company Service Bulletin #9, dated September 12, 1991, had identified flaperon hangar rib failures on Kitfox models I, II, and III. The service bulletin recommended the addition of an aluminum reinforcement on each flaperon hanger rib end. The accident airplane did not have the reinforcement installed. ## Aircraft - Registration: N73BH (not matched to a registry record) - Reported make and model: HARTLINE J BON HARTLINE KITFOX III (III) - Category: Airplane, amateur-built - Serial number: 1000 - Year built: 1991 - Airframe hours: 1184.6 - Engines: Rotax 912 65 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, May 23, 2017, 3 hours before - Departed: 6TX9, Marathon, TX - Destination: 6TX9, Marathon, TX - Airport: 6TX9, Stovall Ranch Airport - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: minor; airline transport; airplane ratings: single-engine sea, multi-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: sport pilot; last flight review May 5, 2017; seat: left; restraint: 4-point; flight hours: 20,000 total, 130 in this make and model, 35 in the last 90 days, 29 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 21 knots, gusting 34 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 30 °F - Altimeter: 30.04 inHg - Observed at: KE38, 100 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 20180502004459A](https://openairdocs.org/incident/20180502004459A), May 2, 2018: Hartline J Bon HARTLINE KITFOX III, Marathon, TX, Destroyed. On may 2, 2018, at approximately 1018 CDT, N73BH, a Hartline Kitfox III experimental aircraft impacted terrain after flaperon failure during take-off climb at… ## Docket (5 files) The files NTSB released with the investigation on January 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97161. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 271 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479918&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum for the Record FAA Examination Summary CEN18LA157 (item 2, .PDF, 181 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479919&FileExtension=.PDF&FileName=Memorandum%20for%20the%20Record%20FAA%20Examination%20Summary%20CEN18LA157-Master.PDF - Memorandum for the Record Airplane Owner Information Summary CEN18LA157 (item 3, .PDF, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479920&FileExtension=.PDF&FileName=Memorandum%20for%20the%20Record%20Airplane%20Owner%20Information%20Summary%20CEN18LA157-Master.PDF - Manufacturer Service Bulletin No 9 September 12 1991 (item 4, .PDF, 136 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479921&FileExtension=.PDF&FileName=Manufacturer%20Service%20Bulletin%20No%209%20September%2012%201991-Master.PDF - Photo Array CEN18LA157 (item 5, .PDF, 335 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479922&FileExtension=.PDF&FileName=Photo%20Array%20CEN18LA157-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.