Uncontrolled Cabin Altitude Ascent on LASER Airlines DC-9-83

Casualties unknown • EN RUTA SVMI-SKBO., VE

A Douglas DC-9-83 experienced an uncontrolled cabin altitude climb following the activation of anti-ice systems, forcing a return to Maiquetia.

What happened

On October 8, 2025, at 13:30 UTC, a Douglas DC-9-83, registration YV3465, operated by LASER Airlines (Línea Aérea de Servicio Regional, C.A.), was performing a scheduled flight from Maiquetia International Airport to El Dorado International Airport in Bogotá, Colombia. The aircraft was carrying 38 passengers and 9 crew members.

While cruising at 32,000 feet, the crew encountered adverse weather conditions and activated the anti-ice system and airframe performance systems. Approximately 15 minutes after activating the anti-use system, the cabin altitude began to rise uncontrollably at a rate of 500 feet per minute, accompanied by a "PRESSURIZATION FLOW" warning light. The crew followed the Quick Reference Handbook (QRH) procedures, but the condition persisted. After requesting descent clearances to 28,000 feet and 26,000 feet and deactivating the anti-ice system without success, the captain decided to return to the departure airport. Upon descending to 23,000 feet, the crew was able to regain control of the pressurization. The aircraft landed safely at Maiquetia with no injuries to the passengers or crew.

The investigation

Investigators conducted interviews with the flight crew and reviewed all relevant documentation, including pilot licenses, medical certificates, and aircraft maintenance logs. The inspection focused on the air conditioning and pressurization systems. Technical troubleshooting was performed in coordination with the airline's maintenance organization (OMAC N° 475).

Findings

  • The investigation identified a malfunction within the air conditioning pressure supply system.
  • Troubleshooting revealed that both the left and right pressure regulating shutoff valves were faulty.
  • The uncontrolled cabin altitude ascent was directly linked to the failure of these components following the activation of the anti-ice system.

Probable cause

The uncontrolled increase in cabin altitude was caused by the failure of the left and right pressure regulating shutoff valves.

Frequently asked questions

What happened in the 2025-10-08 MCDONNELL DOUGLAS DC-9-83 accident near EN RUTA SVMI-SKBO., VE?

A Douglas DC-9-83 experienced an uncontrolled cabin altitude climb following the activation of anti-ice systems, forcing a return to Maiquetia.

What aircraft was involved and where did it happen?

The accident on 2025-10-08 involved a MCDONNELL DOUGLAS DC-9-83, registration YV3465, operated by LASER AIRLINES, C.A, at EN RUTA SVMI-SKBO., VE.

What was the probable cause of the accident?

The uncontrolled increase in cabin altitude was caused by the failure of the left and right pressure regulating shutoff valves.

Investigation report by the Venezuelan Civil Aviation Accident Investigation Board (JIAAC Venezuela). Original record: https://www.mppt.gob.ve/download/188056/. This page is a structured re-presentation; facts and quotes are in the Junta de Investigacion de Accidentes de Aviacion Civil (JIAAC), Venezuela - MppT.

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