Challenger 604 T7-SEI Loses a Door Climbing Out of Abuja, Lands Safely With Nine on Board

A Bombardier Challenger 604 registered T7-SEI lost a door shortly after departing Abuja for Lagos on October 15, 2026, and returned to land safely with nine people on board. The Nigerian Safety Investigation Bureau (NSIB) has opened an investigation and says it has recovered the door.

The Bureau set out the sequence in a statement on October 16 from its Director General and CEO, Captain Alex Badeh Jr., which TheCable and other Nigerian outlets quoted at length.

What the NSIB says happened

According to the statement, the jet departed Nnamdi Azikiwe International Airport at 1612 UTC. Three nautical miles out, passing 3,500 feet, the crew declared a mayday after the aircraft’s door separated.

The aircraft turned back and landed on Abuja’s Runway 22 at 1634 UTC, 22 minutes after departure. On board were three crew members and six passengers.

The NSIB said the door “has been recovered and secured at the NSIB wreckage hangar” and that its investigation will establish the circumstances of the occurrence. It has not given a cause.

The statement names the operator as Triton, which Nigerian media identify as Triton Aviation. The jet is registered in San Marino, which Premium Times reported the NSIB statement also noted.

What the control tower saw

An air traffic control incident report, quoted by Daily Trust and ThisDay, adds the view from the ground. It identifies the flight as DWC052 and says the crew reported that a door had opened in flight.

The report, as Daily Trust quotes it, puts the jet about three nautical miles out and climbing through 3,000 feet at the time, slightly lower than the NSIB’s 3,500 feet. It also logs the takeoff at 1617 UTC, five minutes after the NSIB’s departure time.

The approach radar controller directed the aircraft back to Abuja, and airport fire, rescue and medical teams were put on standby. At 1629 UTC the crew asked the tower whether controllers could confirm if the door was open.

The duty controller tried with binoculars but could not see the door’s condition because of the aircraft’s position. Only after the landing did the controller see that the door was missing from the fuselage.

The jet then taxied to the international apron extension, where the crew reported the marshaller in sight at 1640 UTC and was guided to parking.

Separately, a video shared on social media appears to show farmers with an aircraft door they said they found on farmland in the Abuja area. The NSIB has not said where the door it recovered came down.

Which door, and why it matters

Neither the NSIB statement nor the control tower report, as published, says which door separated. On a Challenger 600-series jet that is a real question, because the fuselage has several openings.

The design has a large main door on the left side ahead of the wing, a baggage hatch on the left side behind the wing, and emergency exits. The fuselage was designed for a maximum pressure differential of 9.3 psi.

Each of those openings is a different structure, so the recovered door gives investigators the hardware itself to examine alongside the aircraft. Until the NSIB reports, any cause is speculation.

The 604 was launched in 1995 and, by 2018, was the best-selling variant of the Bombardier Challenger line. It was followed in 2006 by the Challenger 605, which added larger cabin windows, a new tail cone and updated avionics.

What happens next in the NSIB investigation

The NSIB investigates under ICAO Annex 13, the international standard for accident and incident investigation. The Bureau describes its job as preventing recurrence, not assigning blame.

Annex 13 asks the investigating state to send a preliminary report within 30 days of an occurrence. A final report should follow within 12 months where possible, with an interim statement on each anniversary if it does not.

The Bureau’s handling of another Challenger this year shows the pattern. After a Challenger 601-3A, N989BC, landed on a road under construction near Asaba Airport on June 10, 2026, the NSIB released its preliminary report on July 9.

That report set out facts, initial findings and immediate safety recommendations, but no conclusions on cause, which the Bureau reserves for its final report.

For T7-SEI, the NSIB said it will give further updates as the investigation progresses. No further update had appeared on its website at the time of writing on October 17.