Cabin Depressurization on LASER MD83 Flight from Caracas to Puerto Ordaz (YV480T)

Incident Overview and Flight Details On June 16, 2022, at 12:03 UTC, aircraft registration YV480T, operated by Línea Aérea de Servicio Ejecutivo Regional, S.A. (LASER), departed from Simón Bolívar International Airport (SVMI) in Caracas, Venezuela, bound for Manuel Piar International Airport in Puerto Ordaz. The aircraft was a McDonnell Douglas DC-9-81 (MD83), serial number 53043, configured for 160 passengers and six crew members. It was powered by two Pratt & Whitney JT8D-219 turbofan engines. During the descent phase, the aircraft experienced progressive cabin depressurization, causing emergency oxygen masks to deploy. The pilot in command followed emergency procedures according to the Quick Reference Handbook (QRH) and completed the flight to the destination. The aircraft landed without further discrepancies, and all occupants were unharmed with no reported damage to the aircraft. ## Aircraft and Crew Information The MD83 featured a tricycle retractable landing gear and had a maximum takeoff weight of 142,000 lb. It held valid certificates of registration, airworthiness, and radio station issued by the Venezuelan aeronautical authority, INAC. The maintenance organization supporting the operator was Laser Airlines OMAC N 475. The pilot in command was 66 years old with 25,852 flight hours, holding a medical certificate, Airline Transport Pilot license, and MD80 captain and instrument ratings. The first officer was 52 years old with 6,537 flight hours, holding a commercial pilot license and MD80 first officer and instrument ratings. ## Investigation Findings Investigators conducted a visual inspection and photographic documentation of the aircraft's external structure and engine 1. They found a loose flexible connection on the pneumatic system No. 1 tubing, which supplies the pressurization and air conditioning package No. 1. The clamps used to secure this flexible connection were of the non-locking type. In the cabin, numerous passenger oxygen masks were deployed, but only six were activated. Engine 1 was placed in custody by the investigation board. The flexible connection clamps were replaced with locking-type clamps to prevent recurrence. A functional test of the pneumatic system confirmed it operated correctly, and cabin pressurization with engine 1 running also functioned properly. ## Probable Cause and Safety Recommendations The Venezuelan Civil Aviation Accident and Incident Investigation Board (JIAAC) determined that the probable cause of the incident was a material factor: the disconnection of a flexible connection on the pneumatic system No. 1 tubing due to loss of clamp tension, as the clamps used were of the non-locking type. The JIAAC recommended that LASER inspect and replace the flexible connection clamps on the pneumatic system tubing of MD-80 series aircraft with locking-type clamps. ## Notifications and Reporting In accordance with Annex 13 of the Convention on International Civil Aviation, the incident was reported to the ICAO ADREP system on June 16, 2022. The United States, as the state of design and manufacture, was notified via email to the NTSB. As of the preliminary report date, neither the NTSB nor the ICAO ADREP system had issued a response. The preliminary report was issued in Caracas on July 6, 2022.