WPR21LA108 · Abbett Gerry LANCAIR EVOLUTION
Abbett Gerry LANCAIR EVOLUTION · Accident: part(s) separation from aircraft en route
From Afton Municipal Airport (AFO) to Porter County Municipal Airport (VPZ)
Event
- NTSB case
- WPR21LA108
- 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
- Event fatalities
- Unknown
- 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
Abbett Gerry LANCAIR EVOLUTION
- Aircraft type
- Abbett Gerry LANCAIR EVOLUTION
- 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
- N7569A
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Afton Municipal Airport (AFO), Afton, WYTo Porter County Municipal Airport (VPZ), Valparaiso, IN
- Aircraft age
- About 5 years (built 2016)
- 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
- 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
- Part(s) separation from aircraft
- 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 structures
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
While in cruise flight at 27,000 ft mean sea level, the experimental, amateur-built airplane’s windshield shattered, followed immediately by a rapid decompression of the cabin. The pilot performed an emergency descent and landed uneventfully. The windshield was substantially damaged.
Examination revealed that the fracture originated from a small crack located at the exterior surface of the windshield within the bonded edge. The presence of parallel linear scratches near the fracture origin and on the windshield edge suggests that the bonded area was not sanded in accordance with the build instructions. The evidence also suggests that the in-service stresses in the as-manufactured windshield were high enough to cause fractures from scratches that deviated from the build instructions; therefore, it is likely that the windshield failure was the result of stress concentrations in the bond area due to scratches made with methods inconsistent with the build instructions.
Probable cause
A windshield failure during cruise flight due to stress concentrations in the bond area as a result of improper assembly of the windshield.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR21LA108
- Event ID
- 20210209102614
- Case number
- WPR21LA108
- 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: local date, investigation status, coordinates, cause areas. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2021-02-08.
- API snapshot SHA-256: 33ec7529e7e02120721fc39c7a3f83c9604e6974a40d697a1822c2882eeeb353; retrieved 2026-09-16T13:37:23.608Z.