Event Narrative
The pilot-in-command reported smelling smoke while the aircraft was descending. Smoke was observed emanating from the bottom left corner of the first officer's windscreen. The first officer then used a portable halon fire extinguisher to extinguish a flame, approximately 6 to 8 inches in length, that had appeared from behind the glareshield. Following the incident, the pilot-in-command completed the approach and landing without further issues.
Examination Findings
The windshield was examined by its manufacturer. The examination determined that the source of the excessive heat, which caused the windshield and adjacent aircraft materials to smoke and ultimately burn, was arcing from a damaged low power braided copper lead wire. According to the examiner, it was their opinion that the damage to the braid wire occurred during the windshield manufacturing process.
Additionally, the origin of a fracture in the inboard glass ply was located in the bottom center post corner area near the low power terminal block. The examiner reported that the glass fracture occurred as a result of the intensive heat generated by the electrical arcing of the severed low power lead wire.