CEN18LA157 · Hartline J BON HARTLINE KITFOX III
Hartline J BON HARTLINE KITFOX III · Accident: flight control system malfunction/failure during takeoff
From Stovall Ranch Number 4 Airport (6TX9) to Stovall Ranch Number 4 Airport (6TX9)
Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- CEN18LA157
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Hartline J BON HARTLINE KITFOX III
- Aircraft type
- Hartline J Bon HARTLINE KITFOX
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N73BH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Stovall Ranch Number 4 Airport (6TX9), Marathon, TXTo Stovall Ranch Number 4 Airport (6TX9), Marathon, TX
- Aircraft age
- About 27 years (built 1991)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Takeoff
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Flight control system malfunction/failure
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft systems
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN18LA157
- Event ID
- 20180503X02040
- Case number
- CEN18LA157
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: d95e0894518b7a726540594e0597b00b38b770e058e33da6a394a37728f5e011; retrieved 2026-09-16T07:00:14.976Z.