Background
On 24 November 2014, the crew of a Gulfstream III, registration N103CD, planned a private flight from Biggin Hill Airport to Gander International Airport, Canada. The weather at 2020 hrs was calm winds, visibility greater than 10 km with fog patches, no significant cloud, temperature 5°C, dew point 4°C, and QNH 1027 hPa.
Pre-Takeoff Events
At 2024 hrs, the crew received clearance to taxi to Holding Point J1 for departure from Runway 03. The controller informed them of low-level fog patches on the airfield, noting that visibility in patches was not measured, and described thin fog from the Runway 03 threshold to approximately halfway down the runway, beyond which it appeared clear. The crew acknowledged.
Takeoff Attempt
At 2028 hrs, at the holding point, clearance for takeoff was given. The aircraft taxied from J1 but aligned with runway edge lights positioned 3 m right of the runway edge. At 2030 hrs, the aircraft began its takeoff run, passing over paved surface for about 248 m before entering grass. The commander, handling pilot, closed thrust levers to reject the takeoff. The aircraft stopped on grass with major structural damage.
Post-Accident Actions
The crew shut down engines but could not contact ATC. The co-pilot entered the passenger cabin, confirmed no injuries, then exited via the rear baggage compartment. He helped the commander open the main exit; the commander and five passengers evacuated through it. The controller saw the aircraft stop but did not realize it was off the runway. After seeing aircraft lights switch off, he activated the crash alarm at 2032 hrs. Airport fire service reached the aircraft at 2034 hrs and declared an accident, activating the emergency plan.
Investigation Findings
The investigation noted that the flight could not depart in conditions with RVR less than 400 m, but RVR was not measured at the threshold. The crew reported moisture on windscreen and a glow around lights; they were aware of patchy fog. The controller's fog information was not considered significant by the crew at the time. After the abort, the controller could only see the top of the aircraft above fog, suggesting visibility was worse than perceived. The aerodrome chart used by the crew did not accurately reflect the taxi route from J1, which involved multiple turns. The UK AIP stated no centreline lighting on Runway 03 and wider pavement at the beginning, but this info was not on the crew's charts. Both crew members believed the runway had centreline lighting. The fog scattered light from left-side runway edge lights, making them harder to see. Bright apron lights reflecting off fog further reduced visibility of runway lights. Five factors typical of misaligned takeoffs were present: darkness, confusing taxiway environment, extra paved area (ORP), lack of centreline lighting with recessed edge lights before displaced threshold, and reduced visibility. The crew's incorrect expectation of their route was reinforced by the first right turn nearly aligning them with lights. Cues like red edge lights on the other side or ahead were not strong enough to correct their situational awareness. The recessed nature of red edge lights made them less compelling than elevated white lights.