Bemidji Aviation Services Flight 25
Beech E90 · Incident: aircraft structural failure en route
From Park Rapids Municipal Airport Konshok Field (KPKD) to Chicago Executive Airport (KPWK)
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
- CEN14IA085
- 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
- Incident
- 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
- Charter & commuter
- 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
Beech E90
- Aircraft type
- Beechcraft 90
- 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
- N60BA
- Operator
- Bemidji Aviation Services
- Onboard fatalities
- Unknown
- Route
- From Park Rapids Municipal Airport Konshok Field (KPKD), Park Rapids, MNTo Chicago Executive Airport (KPWK), Wheeling, IL
- Aircraft age
- About 20 years (built 1993)
- 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 135: Air Taxi & Commuter
- 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
- Aircraft structural failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Aircraft › Aircraft structures
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The operator reported that, while in cruise flight at flight level 190, the copilot's inner layer windshield cracked. Windshield heat was not being used at the time, and pressurization was not compromised. The pilot conducted a precautionary landing without incident. Examinations of the windshield revealed that the inner glass ply had fractured due to a peel adhesion chip at the windshield's lower forward corner. The peel chip developed as a result of the differences in coefficient of expansion between the inboard glass ply and vinyl interlayer and had propagated due to mechanical and thermal expansion stresses until the center tension of the thermally tempered glass was penetrated, which caused a spontaneous fracture. The windshield was redesigned in 2001 to reduce the thermal expansion stresses.
Probable cause
The failure of the copilot’s windshield inner layer due to a peel chip that developed as a result of mechanical and thermal expansion stresses.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN14IA085
- Event ID
- 20131214X34904
- Case number
- CEN14IA085
- 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: 08d766b2a8891e23cd336f2995f0915591cf73f6701c2a3a4db136b4a4668903; retrieved 2026-09-15T23:11:10.677Z.