Boeing 737-33A Window Fracture During Cruise (YV642T)

Incident Overview and Flight Details On March 21, 2025, at 12:22 UTC, a Boeing 737-33A with registration YV642T and serial number 27267 filed a flight plan from Simón Bolívar International Airport in La Guaira state to General Juan Vicente Gómez Airport in San Antonio del Táchira, Táchira state. The aircraft, owned by Estelar Latinoamérica, C.A, was carrying five crew members and 70 passengers. ## Event Description At 12:50 UTC, while cruising at flight level 320 near Barquisimeto in Lara state, the flight crew observed a fracture in the R1 cockpit window on the copilot's side. The crew immediately initiated emergency procedures outlined in the Quick Reference Handbook (QRH). The captain informed the cabin manager and notified the Area Control Center of the decision to return to Maiquetía. The aircraft was authorized for a final approach and landed without further incident. All crew and passengers were unharmed, and the aircraft sustained only the reported window damage. ## Aircraft and Maintenance Background The aircraft is a twin-engine turbofan powered by two CFM56-3 engines manufactured by Douglas Aircraft Company. It was certified as airworthy by the National Institute of Civil Aeronautics (INAC) at the time of the incident. The last preventive and scheduled maintenance was performed by Estelar Techik C.A. (OMAC No. 681) at Simón Bolívar International Airport. ## Crew Qualifications The 55-year-old pilot held a valid Airline Pilot License and medical certificate from INAC, with type ratings for B733/B734 as Captain/PIC valid until December 20, 2025. He had logged 134 hours as pilot-in-command in the preceding 90 days. The 37-year-old copilot held a valid Commercial Pilot License and medical certificate, with type ratings for B733/B734 as Copilot/SIC valid until April 25, 2025. He had logged 133 hours as copilot in the preceding 90 days. ## Investigation and Findings Investigators interviewed the flight crew and collected documentation including licenses, medical certificates, flight logs, flight plans, registration and airworthiness certificates, radio station licenses, insurance policies, and acoustic certification. Maintenance records from OMAC No. 681 were also reviewed, including maintenance organization certificates, approved capability lists, component controls, airworthiness directive compliance, scheduled maintenance controls, and the last maintenance certificate of conformity. Meteorological conditions were unlimited and favorable throughout the day for operations along the flight route. A thorough inspection of the affected window revealed that the systems designed to preserve the window's thermal resistance were functioning according to manufacturer parameters, ruling out these systems as causal factors. ## Probable Cause The Civil Aviation Accident Investigation Board (JIAAC) determined that the probable cause was directly related to previous external damage, impacts, or damage caused by the interaction of foreign objects (FOD). The investigation was closed based on these findings.