Preliminary findings from the Nigerian Safety Investigation Bureau (NSIB) have revealed that all locking mechanisms, alongside both the internal and external handles, of the passenger-crew door that detached mid-air from a Bombardier Challenger 604 aircraft were found in the open position following the incident.
​The disclosure was made in a preliminary investigation report released by the Bureau on Wednesday, November 11, 2026, and detailed in an official statement signed by the Director-General and Chief Executive Officer of the NSIB, Captain Alex Badeh Jr.
​The serious incident occurred on October 15, 2026, involving a San Marino-registered Bombardier Challenger 604 private jet, bearing registration number T7-SEI and operated by Triton Aviation Limited.
Operating as non-scheduled flight DWC052, the aircraft had departed the Nnamdi Azikiwe International Airport (NAIA), Abuja, en route to the Murtala Muhammed International Airport (MMIA), Lagos, with nine persons on board, comprising two pilots, one cabin crew member, and six passengers.
​According to the NSIB report, the emergency unfolded rapidly shortly after takeoff. At approximately 17:19 local time during the initial climb out of Abuja, the flight crew observed an abnormal increase in cabin altitude and suspected a pressurisation issue. In response, the captain instructed the lone cabin crew member to double-check the security of the main cabin door.
However, as the crew member approached the passenger-crew door to inspect it, the door suddenly swung open and detached completely from the fuselage. The separated door struck the aircraft’s lower fuselage, damaging a VHF antenna before falling into a cornfield in Gui, Abuja, where investigators later recovered it.
​Following the mid-air separation, the captain assumed flying control of the aircraft while the first officer took over pilot-monitoring duties. The crew immediately declared an emergency and coordinated with Abuja Air Traffic Control (ATC) for an immediate return to the capital.
At 17:34 local time, roughly 15 minutes after the initial pressurisation anomaly was detected, the jet landed safely on Runway 22 at Nnamdi Azikiwe International Airport. All nine occupants disembarked safely using an improvised ladder without sustaining any injuries.
​Post-incident physical and technical inspections conducted by NSIB investigators uncovered critical anomalies regarding both the mechanical state of the door and crew regulatory compliance.
Inside the flight deck, the cockpit door indicator displayed an “UNLOCKED/RED” warning, while physical examination of the recovered door confirmed that all locking mechanisms, as well as the internal and external handles, were in the open position.
Despite this unlocked state, the flight crew reported receiving no aural or visual door warnings prior to takeoff or before the door detached in flight.
​A structural assessment of the recovered door showed that while it sustained damaged handrails and a detached rubber seal upon impact, the locking mechanisms on the door frame itself remained intact with no signs of forced opening.
Furthermore, a review of the aircraft’s maintenance diagnostic records showed no prior door-related faults. However, investigators uncovered a significant regulatory breach regarding personnel documentation.
While both pilots were duly qualified and the aircraft held valid airworthiness and operational clearances, the Bureau discovered that the sole cabin crew member on board did not possess a valid medical certificate at the time of the flight.
​In light of these preliminary findings, the NSIB issued two immediate safety recommendations aimed at preventing a recurrence. The Bureau directed Triton Aviation Limited to ensure that all crew members deployed for flight operations strictly meet regulatory requirements regarding licensing, medical fitness, and emergency competency.
Simultaneously, the NSIB urged the Nigerian Civil Aviation Authority (NCAA) to immediately strengthen its safety oversight of Permit for Non-Commercial Flight (PNCF) holders that engage cabin crew members for safety-related duties.
​Captain Alex Badeh Jr. and the Bureau emphasized that the investigation remains active and ongoing. Subsequent phases of the inquiry will involve metallurgical testing, detailed examinations of the detached door’s assemblies and locking systems, and thorough reviews of flight recorder data and maintenance practices.
A final report detailing the root causes of the separation and further safety directives will be published upon conclusion of the probe in accordance with Annex 13 to the Convention on International Civil Aviation.
