The Nigerian Safety Investigation Bureau (NSIB) has commenced investigation into an occurrence involving a Challenger 604 aircraft, registration T7-SEI, operated by Triton.
According to a statement signed by its Director General, Captain Alex Badeh jnr, the NSIB said the aircraft departed Abuja on Thursday October 15, 2026 for Lagos at 1612 UTC.
He said the aircraft after departure inching three nautical miles into its journey having climbed 3,500 feet above sea level, the crew declared emergency, known in aviation parlance as: “mayday” after the aircraft’s door separated.
The aircraft, the NSIB said, returned to Abuja and landed safely on Runway 22 about 1634 UTC, with nine persons on board, comprising three crew members and six passengers.
The NSIB said the door had been recovered and secured at its wreckage hangar.
The Bureau, Badeh said, had commenced its investigation to establish the circumstances surrounding the occurrence.
The NSIB said it will provide further updates as the investigation progresses.
Experts have, however, expressed concerns over the increasing incidents related to safety, urging relevant agencies to ramp up surveillance.
The incident of aircraft door separation is new to the Nigerian airspace.
In the United States, there are reported incidents.
In-flight door separations have occasionally been documented on earlier Challenger models, including: Challenger 601 and 600 series jets, where latching mechanisms or warning/indication light sequences prior to takeoff were focal points for aviation safety investigators.
The main entry door on Bombardier Challenger aircraft such as the Challenger 601 and Challenger 604) has experienced rare in-flight door separation incidents shortly after takeoff.
In -flight door separations have historically occurred on older Bombardier Challenger variants (such as the Challenger 601) under similar low-altitude climb conditions.
Past investigations often focused on: Latch or locking mechanism engagement verification – “Door Safe” warning lights or reset switches.
On May 23, 2012, a similar incident occurred in Opa- Locka , Florida, when a Challenger 601-3R business jet (registration N207JB) owned by Medcp Aviation was climbing through 3,000 feet after departing Opa-locka Airport for a short repositioning flight.
The main entry door separated under unknown circumstances.
The crew declared an emergency and safely diverted to Fort Lauderdale-Hollywood International Airport.
The door and its attached air stair landed on a nearby golf course, narrowly missing residential high-rises.
There were no injuries. Investigators noted the co-pilot believed the door-safe lights were functioning but could not explicitly recall seeing them illuminated.