History of the Flight
On 13 June 2022, the aircraft departed Port Harcourt Military Airport at 12:16 h for Forcados Airstrip. After landing at 13:03 h, the Line Training Captain briefed two trainee pilots on circuit training. The first sortie, a right-hand pattern, was flown with Trainee Pilot 2 as pilot flying from 13:26 to 13:36 h. After landing, engine No. 1 was shut down. The crew prepared for an additional circuit before returning to Port Harcourt, as six passengers were awaiting pickup.
For the second sortie, four persons were on board: the three pilots and one maintenance engineer. At 13:43 h, with Trainee Pilot 1 as pilot flying and the Line Training Captain as pilot monitoring, engine No. 1 was started and taxi clearance obtained. Initially cleared to return, the crew requested a revised clearance for another right-hand circuit, which was granted. After a brief pause to adjust the seat, the aircraft was cleared for take-off on Runway 20. Initial wind was reported as 080°/05 kts, later updated to 220°/08 kts. During the take-off roll, the pilot flying was cautioned against applying brake pressure.
The circuit and approach were conducted in varying crosswind conditions. The trainee pilot received repeated advisory inputs on crosswind correction and power management. Flap extensions were accompanied by low-speed aural warnings, requiring additional thrust. The approach was deemed stable at 500 ft, but lateral alignment challenges persisted. The aircraft touched down on Runway 20 and immediately veered left, exiting the runway onto the grass verge. The aircraft came to rest with the left wing and landing gear embedded in the soft ground, sustaining damage.
Personnel Information
The Line Training Captain (pilot monitoring) held a valid Airline Transport Pilot License and was qualified as an instructor on the DHC-6-400. The Trainee Pilot 1 (pilot flying) held a valid Commercial Pilot License and was undergoing line training. Both trainee pilots were already captains on the DHC-6-400.
Aircraft Information
The aircraft was a De Havilland Twin Otter DHC-6-400, serial number 864, manufactured in August 2012, with Nigerian registration 5N-SHE. It was equipped with two engines and two propellers. The aircraft had a valid certificate of airworthiness and was maintained by an approved maintenance organization.
Meteorological and Aerodrome Information
The weather at Forcados Airstrip included variable crosswind conditions. The aerodrome has a single asphalt runway designated 20/02.
Flight Recorder Information
The aircraft was equipped with a Solid State Cockpit Voice Recorder and a Solid State Flight Data Recorder. Data from these recorders were analyzed to reconstruct the flight path, showing the circuit patterns and the final approach.
Conclusions
The Nigerian Safety Investigation Bureau determined the causal factor to be insufficiently sustained crosswind corrections during the flare and landing roll. A contributory factor was limited anticipatory management of crosswind effects throughout the circuit and final approach. One safety recommendation was made.