NSIB Releases Preliminary Report on In-Flight Door Separation Involving Triton’s Challenger 604
The Nigerian Safety Investigation Bureau (NSIB) has released its preliminary report on the in-flight separation of a passenger-crew door from a Bombardier Challenger 604 aircraft operated by Triton Aviation Limited, during an Abuja-Lagos flight on October 15, 2026.
The Director-General and Chief Executive Officer of NSIB, Captain Alex Badeh Jr., disclosed this in a statement made available to ThelensNG on Thursday.
The aircraft, with nationality and registration marks T7-SEI, was operating a non-scheduled flight as DWC052 from the Nnamdi Azikiwe International Airport, Abuja, to the Murtala Muhammed International Airport, Lagos, with nine persons on board, comprising two flight crew members, one cabin crew member and six passengers.
The incident occurred at approximately 5:19 pm local time during the aircraft’s initial climb, when the flight crew noticed an abnormal increase in cabin altitude and suspected a pressurisation problem.
According to the report, the captain subsequently instructed the cabin crew to double-check the main cabin door. However, as a cabin crew member approached the passenger-crew door to inspect it, the door opened and subsequently detached from the aircraft.
Following the incident, the flight crew declared an emergency and coordinated with Abuja Air Traffic Control (ATC) for an immediate return to the airport.
The aircraft subsequently landed safely on Runway 22 at approximately 5:34 pm, with all nine occupants disembarking without injury. However, the aircraft sustained substantial damage.
The NSIB said it deployed investigators to the scene immediately after receiving notification of the occurrence on the same day, with the initial investigation focusing on locating and recovering the detached door and conducting post-occurrence assessments.
The detached door was later recovered from a cornfield in Gui Village, Abuja Municipal Area Council, approximately five miles southwest of the airport.
The Bureau said the preliminary report contains factual information established so far, including initial findings based on available evidence and immediate safety recommendations arising from safety issues identified during the investigation.
It, however, clarified that the report does not contain any analysis or conclusions on the causes or contributing factors associated with the incident, as investigations are still ongoing.
The NSIB stated that a final report containing its analysis, conclusions and any additional safety recommendations, where appropriate, would be published upon completion of the investigation in accordance with ICAO Annex 13 to the Convention on International Civil Aviation.
The Bureau added that the preliminary report is available for download on its website.
