What happened
On June 11, 2015, a Hawker Siddeley HS-125-800 XP aircraft, registered as N497AG and operated by SWAT Technology Limited, arrived at Port Harcourt International Airport from Abuja. The charter flight carried five people: three crew members and two passengers. The Captain served as the Pilot Flying (PF), while the Co-Pilot acted as the Pilot Monitoring (PM).
The aircraft descended through Flight Level 210 under Instrument Flight Rules. As it approached Port Harcourt, the crew reported sighting the field at six nautical miles from touchdown. Air Traffic Control cleared them for landing on Runway 21, noting that the runway surface was wet due to light rain.
During the final approach, the cockpit voice recorder captured a conversation unrelated to flight operations between the pilots, violating sterile cockpit protocols. As they neared decision height, the PM noted that the runway centerline lights were missing and that the right-side edge lights were largely inoperative. The PM repeatedly instructed the PF to correct the aircraft’s position to the right, but the PF appeared unable to align with the available visual references.
At approximately 19:16 local time, the aircraft touched down with its left main wheel on the grass verge and its right main wheel on the runway. The PF later admitted to mistaking the bright left edge lights for the centerline, a classic symptom of the "black hole" visual illusion common in night approaches over featureless terrain. After steering back onto the tarmac, the nose landing gear collapsed under stress, bringing the aircraft to a halt. All occupants evacuated safely without injury.
The investigation
The Accident Investigation Bureau examined the flight data recorder, cockpit voice recordings, and physical wreckage. Key findings included:
- The aircraft was airworthy and within weight limits.
- Both pilots held valid licenses and medical certificates.
- The runway centerline lighting system for Runway 21 was not installed at the time.
- Most of the right-side runway edge lights were unserviceable due to an earth fault caused by heavy rain, leaving only the left side brightly illuminated.
- The windshield wipers were inoperative, further impairing visibility during the rain.
Findings
The investigation concluded that the primary cause was the black hole effect, which disoriented the pilot and led to a low-level maneuver into the grass verge. Contributing factors included:
- The majority of Runway 21’s right edge lights were unserviceable during the landing.
- Inadequate Crew Resource Management, including non-flight-related chatter during critical phases and failure by the PM to take control when deviations became apparent.
Safety action
The investigation issued Safety Recommendation 2021-028, urging the Federal Airports Authority of Nigeria (FAAN) to ensure the continuous serviceability of runway lighting systems at Port Harcourt International Airport during all operations.