CHI06LA268 · Windler Tri Q2
Windler Tri Q2 · Accident: airframe, component or system failure en route
From M. Graham Clark Downtown Airport (PLK) to Kansas City International Airport (MCI)
Event
- NTSB case
- CHI06LA268
- 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
- 1 · 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
Windler Tri Q2
- Aircraft type
- Windler TRI Q2
- 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
- N6628K
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From M. Graham Clark Downtown Airport (PLK), Point Lookout, MOTo Kansas City International Airport (MCI), Kansas City, MO
- Aircraft age
- Not recorded
- 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
- En route · descent
- First occurrenceThe 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
- Airframe, component or system 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
- Destroyed
Cause areas
- Flight control, elevator attachment › Corroded
- Flight control, elevator attachment › Failure
- Flight control, elevator attachment › Fatigue
- Flight control, elevator › Separation
- Pilot in command › Aircraft control, not possible
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The airplane was destroyed when it impacted trees and terrain during an uncontrolled descent, which resulted from an in-flight separation of the right elevator. A witness reported that the airplane appeared to be in a descent as if approaching to land, when something separated from the airframe. A second witness reported the airplane banked to the right, "winged over," and began a clockwise descending spiral. The right elevator was recovered approximately 1,250 feet from the accident site. Examination of the elevator revealed corrosion and fatigue failure of the mid span hinge pivot pin. The examination also noted surface corrosion on the mid span hinge pin in the area of the fatigue failure. Failure of the mid span hinge pin allowed the control surface to buckle, which subsequently fractured the integral torque tube running along the leading edge of the elevator. Flexing of the control surface permitted the outboard end of the torque tube to slide free of the outboard hinge support. This allowed the elevator to separate from the airframe. In addition, the torque tube cutout at the mid span hinge fitting appeared to be oversized from that shown in the aircraft construction plans. The cutout of the torque tube at the mid span hinge support extended around approximately 120 degrees at the forward side of the tube. According to the plans, the cutout for the hinge was shown to be approximately 80 degrees. The reduced cross section on the torque tube due to the oversized cutout resulted in increased stresses in the area of the cutout.
Probable cause
Fatigue failure, originating in an area of surface corrosion, of the right elevator mid span hinge pin and the subsequent failure of the elevator torque tube. Additional causes are the separation of the elevator from the airframe due to the hinge pin and torque tube failures, and the pilot's inability to maintain control of the airplane after separation of the control surface.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI06LA268
- Event ID
- 20060929X01429
- Case number
- CHI06LA268
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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, coordinates. 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: 897773c8f70574970b72338f68cf3baba28d814c1e93b1ed736989a1a6e565d5; retrieved 2026-09-20T17:02:44.048Z.