Aircraft and Crew
The aircraft involved was a Boeing 737-301, serial number 23260, registered as HK-5370. It was owned by Aerosucre, S.A. and powered by two Pratt & Whitney JT8D-11 turbofan engines with a maximum thrust of 15,000 lbs each. The maximum takeoff weight was 160,000 lb. The aircraft held valid certificates of registration and airworthiness and was in commercial service.
On board were five persons: a pilot, copilot, flight engineer, maintenance technician, and dispatcher. The pilot, aged 53, held a B727 Captain/PIC rating. The copilot, aged 30, held ratings for Instrumental Flight, Dash-8 copilot, B737-NG copilot, and B727 copilot. Both had valid medical certificates and licenses.
Flight Event
The flight was planned from Arturo Michelena International Airport in Valencia, Venezuela (SVVA) to El Dorado International Airport in Bogotá, Colombia (SKBO). After takeoff, the crew was cleared via the Nosca SID and climbed to flight level FL360. Upon reaching the assigned level, a loud noise was heard and the crew observed that the L2 window was cracked. The crew performed the appropriate checklists and verified that the pressurization system was operating normally. The captain decided to return to Valencia, where the aircraft landed without further incident. The crew were uninjured and the aircraft sustained only minor damage.
Weather conditions at the time were reported as winds 0 knots, visibility unlimited, and generally good throughout the day.
Investigation
The investigation was conducted by the Junta Investigadora de Accidentes (JIA). Activities included reviewing documentation such as the aircraft's maintenance records and certificates, interviewing the pilot and copilot, and inspecting the aircraft together with the authorized maintenance organization. The maintenance organization responsible for the aircraft's last scheduled maintenance was Aerosucre, S.A. at Bogotá.
Photographic evidence was taken of the fractured L2 window. The window was replaced following the procedures in the Aircraft Maintenance Manual (AMM) 56-11-11, including the operational test of the window anti-icing system.
Determination
Inspection of the affected area according to AMM 56-11-00 revealed characteristics consistent with an electric arc on the window, as described in AMM 56-11-00, page 626. It was determined that the window was out of limits and required replacement. The investigation was closed with the replacement of the window.