What happened
A Boeing 737-301, registration HK 5370, operated by Aerosucre, S.A., was performing a scheduled flight from Arturo Michelena International Airport in Valencia, Venezuela, to El Dorado International Airport in Bogotá, Colombia. The aircraft was carrying five occupants, including the pilot, co-pilot, flight engineer, maintenance technician, and dispatcher.
After departing Valencia and climbing to the authorized flight level of FL360 via the Nosca instrument departure, the crew heard a loud noise. Upon investigation, the crew observed that the L2 cabin window had become cracked. The crew immediately performed necessary checklists and verified the status of the pressurization system, which was found to be functioning normally. Due to the window damage, the commander decided to execute an emergency return to Valencia. The aircraft landed safely at Arturo Michelena International Airport with no injuries to the occupants and only minor damage to the airframe.
The investigation
The investigation involved a physical inspection of the aircraft alongside authorized maintenance personnel. Investigators reviewed several documents, including the aircraft's airworthiness certificate, maintenance records, and the flight crew's licenses and medical certifications.
Technical inspections were conducted following the Aircraft Maintenance Manual (AMM) procedures. The investigation included photographic documentation of the fractured window and a review of the installation process. Following the inspection, the window was replaced according to AMM 56-11-11 protocols, including operational tests of the window heating/anti-icing system.