Let 410 9Q-CEX was being flown by a Congolese crew on behalf of the Nigerian airline company Sky Executive Airlines. The aircraft departed Abuja around 16:30 for a passenger flight to Port Harcourt. At Port Harcourt all passengers disembarked. The aircraft then took off for a ferry flight to Calabar. On approach the pilot declared an emergency due to an electrical failure. At 65 km out the crew commenced a descent to 2500 feet. The descent was continued past this altitude until the Let crashed in a swamp. During the investigation into the cause of the accident it was found out that the aircraft was non-compliant with the maintenance requirements, and proper documentation of the aircraft and crew members. Also, the plane had exceeded the prescribed annual inspection time by 248 hours, and the engines were not maintained in accordance with the standard procedure. Contrary to NCAA regulations a Flight Data Recorder (FDR), nor a Cockpit Voice Recorder (CVR) were installed. PROBABLE CAUSE: “The premature departure of the plane from the normal minimum safe altitude of 2500 ft without air traffic controller’s clearance until it flew into the terrain. Other contributing factors are the emergence of electrical problem on the aircraft on the commencement of its approach which might have distracted the attention of the pilot from having undistorted focus on the instruments, and unfavourable weather conditions of low cloud base and thunderstorm which impaired visibility at the critical time of descent.”