NSIB: Pressurisation anomaly preceded mid-air door separation on Triton Aviation jet

The Nigerian Safety Investigation Bureau (NSIB) released a preliminary report on Thursday summarising the incident involving a Bombardier Challenger 604 aircraft whose passenger-crew door detached mid-air shortly after take-off from Nnamdi Azikiwe International Airport, Abuja.

The report noted that the flight crew observed an abnormal increase in cabin altitude and suspected a pressurisation issue, prompting the captain to instruct the cabin crew member to double-check the main cabin door.

However, as the cabin crew approached the Passenger-Crew Door to inspect it, the door opened and subsequently separated from the fuselage.

According to the factual details established in the report signed by the Director General and Chief Executive Officer of the NSIB, Captain Alex Badeh Jr., the incident occurred at approximately 17:19 local time during the aircraft’s initial climb.

The aircraft, bearing nationality and registration marks T7-SEI and operated by Triton Aviation Limited as flight DWC052, was on a non-scheduled flight to Murtala Muhammed International Airport, Lagos, with nine persons on board—two flight crew members, one cabin crew member, and six passengers.

Following the mid-air detachment, the flight crew immediately declared an emergency and coordinated with Abuja Air Traffic Control (ATC) for an urgent air return.

The aircraft touched down safely on Runway 22 at approximately 17:34 local time—15 minutes after the anomaly was first detected.

While the aircraft sustained substantial damage, all nine occupants disembarked safely without injuries.

Badeh Jr. further stated that after receiving notification of the accident that day, the NSIB deployed a team of investigators to search for the missing aircraft component and begin post-occurrence assessments.

According to him, the detached door was eventually recovered from a cornfield in Gui Village, within the Abuja Municipal Area Council, roughly five miles southwest of the airport.

The Bureau noted that the preliminary report, now available for download on its official website, outlines only the factual information gathered so far, along with initial findings and immediate safety recommendations to address safety issues identified at this early stage.

“The report does not include analysis or conclusions regarding the causes or contributing factors associated with the occurrence, as the investigation remains ongoing,” the NSIB stated, adding that a comprehensive final report complete with full analysis, conclusions, and further safety recommendations will be published upon the conclusion of the probe in line with ICAO Annex 13 provisions.

Wole Shadare