Incident Overview
On 25 January 2018 at 14:28 hours, a Gulfstream 200 (G200) aircraft, registration 5N-BTF, operated by Nestoil Plc, departed Murtala Mohammed International Airport in Lagos, Nigeria, as a charter flight to Nnamdi Azikiwe International Airport in Abuja. The flight operated under an Instrument Flight Rules (IFR) flight plan with four passengers and three crew members on board. The Pilot in Command (PIC) served as the Pilot Monitoring (PM), while the Co-pilot acted as the Pilot Flying (PF).
Flight Details
The departure, cruise, and approach to Abuja were uneventful. At 14:45 hours, the crew contacted Abuja radar and received clearance for a radar vectors ILS approach to Runway 22. The Automatic Terminal Information Service (ATIS) Papa for 14:20 hours reported: main landing runway 22, wind 110/07 knots, visibility 3,500 meters in haze, no significant clouds, temperature/dew point 33/-01°C, QNH 1010 hPa.
Approach and Landing
At 15:17 hours, the aircraft reported being 4 nautical miles on the ILS. Air traffic control requested a report at 2 nautical miles due to a preceding Gulfstream 5 that was still on its landing roll. Subsequently, 5N-BTF was cleared to land on Runway 22 with a reported wind of 070/07 knots. At 15:18 hours, the aircraft touched down slightly left of the runway centerline. According to the PF, while maneuvering the aircraft back to the centerline, the aircraft skidded left and right and eventually departed the runway on the right side before coming to a stop. The PM reported noticing the aircraft oscillating left and right as brakes were applied, with the oscillation increasing until the aircraft exited the runway to the right, stopping partially on the runway.
Post-Impact Examination
Post-incident inspection revealed skid marks on the runway forming an S-pattern with continuously increasing amplitude down the runway. On the last right turn, the aircraft left the right shoulder of the runway, causing the right main wheel to enter the grass. During the subsequent left turn, the right main landing gear strut detached from its main attachment point. The aircraft came to a complete stop on a magnetic heading of 160°. Air traffic control immediately notified the Aircraft Rescue and Fire Fighting Services (ARFFS), Approach Radar Control, and other relevant agencies. All persons on board disembarked without injuries. Instrument Meteorological Conditions (IMC) prevailed at the time, and the serious incident occurred during daylight hours.
Probable Cause
The official investigation identified the causal factor as the use of improper directional control techniques to maintain the aircraft on the runway. A contributory factor was improper coordination in taking over control of the aircraft by the Pilot Monitoring, which was inconsistent with Nestoil Standard Operating Procedures (SOP).