CHI06LA260 · Endless Skies Aviation Inc. L164
Endless Skies Aviation Inc. L164 · Accident: airframe, component or system failure en route
From Livingston County Spencer J. Hardy Airport (OZW) to Bismarck Municipal Airport (BIS)
Event
- NTSB case
- CHI06LA260
- 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
Endless Skies Aviation Inc. L164
- Aircraft type
- Endless Skies L164
- 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
- N2627J
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Livingston County Spencer J. Hardy Airport (OZW), Howell, MITo Bismarck Municipal Airport (BIS), Bismarck, ND
- 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 · cruise
- 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
- 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
- Flt control syst, aileron control › Flutter
- Owner/builder › Maintenance, installation, improper
- Wing, spar › Failure
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The experimental amateur-built airplane sustained substantial damage when a wing spar failed during cruise. The pilot executed a forced landing to a nearby field. The airplane had accumulated 40.6 hours of flight time. The pilot's accident report, in part, stated, "When the aircraft reached 135 MPH indicated and was at that airspeed for a minute or two in calm stable air it suddenly developed an aileron flutter. Both ailerons fluttered. ... [The passenger] noticed the flutter before [the pilot] because the stick did not shake. The flutter started at the trailing edge of the wing and progressively got worse. Wing tips traveled 4 to 5 [inches] up [and] down. [The pilot] saw the right wing fail in an up position. The flutter stopped at approx 120 MPH. The nearest airport was 8.5 miles away. That was too far away. [The pilot] elected to land in a farmer's field straight ahead before we experienced further wing failure." An on-scene examination revealed that the aileron hinge brackets were not attached to the ailerons as depicted in the kit drawings for the airplane. This airplane kit's aileron hinge brackets were not pre-drilled by the kit manufacturer. Subsequent to the accident, the kit manufacturer issued a service bulletin (SB). That SB, in part, stated, "As of January 2004, Parts L370 R & L are delivered to customer pre-drilled for bolt holes as per attached drawing. Compliance method: Customers who have received the above parts un-drilled should note that the center to center distances of the bolt holes are critical. Particularly those which are for the bolts holding the assembly to the aileron spars. The attached drawing dimensions must be respected."
Probable cause
The kit builder's improper installation of the aileron bracket leading to the aileron flutter during cruise that resulted in the wing spars' failure.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI06LA260
- Event ID
- 20060927X01410
- Case number
- CHI06LA260
- 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. 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: bd64d21eeeb4a206854b5d0235071e7f009c21ffd2f2bae269d6a8ba3374ff23; retrieved 2026-09-22T04:27:05.620Z.