History of the flight
The aircraft, a Fokker 100 registered G-UKFN, was operating a public transport flight from Jersey to Southampton on 24 October 1998. It had earlier departed Stansted for Jersey but was delayed due to weather. The crew came on duty at 1035 hrs. The flight from Jersey departed at 1505 hrs and arrived at Southampton around 1537 hrs.
During the ILS approach to Runway 20, the commander was handling with autopilot and autothrottle engaged. At about 2,000 ft, conditions were smooth with intermittent visual contact. Speed reductions and flap selections proceeded normally. At approximately 500 ft, the minimum allowable speed (Vma) indication disappeared from the speed tape, and the airspeed decayed rapidly to about 120 kt with a SPD LIM caption. The commander moved the power levers forward, disconnected the autopilot, and instructed the first officer to select 150 kt. The aircraft accelerated, and speed was reselected to 136 kt. The commander observed three whites and one red on the PAPIs, indicating a slightly high glideslope, and decided to land.
The touchdown was estimated 150 to 300 metres beyond the ideal touchdown marker. The landing was lighter than desired on a wet runway. Spoilers deployed normally, reverse idle was selected, and the autobrake (set to medium) initially provided sufficient retardation. When more retardation was needed, the commander applied full footbrakes, but retardation did not increase significantly. The first officer also applied brakes with little effect. As the aircraft approached the runway end, the first officer suggested emergency reverse, which the commander selected. The aircraft left the runway and came to rest between the runway end and the arrester bed. The air traffic controller estimated the touchdown point at about 300 metres past the ideal marker and activated the crash alarm. A Full Emergency was declared, later upgraded to Aircraft Accident. The aircraft sustained little damage, and passengers were evacuated without injury.
Aircraft and component examination
After recovery, the aircraft was examined. Wheels and brakes were replaced, and the aircraft was ferried empty to Norwich for comprehensive systems checks. Operational checks of the flap and Attitude/Heading Reference Systems, angle of attack vanes, and autothrottle system revealed no faults. The Flight Mode Panel (FMP) was removed and replaced. Subsequent testing by the aircraft manufacturer and component manufacturer found no significant operating problems, though minor display deficiencies were noted. The tyres and brakes were within wear limits, with no evidence of aquaplaning or hydraulic leakage.
Meteorological conditions
A cold front approached the Southampton area at the time, giving continuous moderate rain. Rainfall amounts recorded included 6.8 mm between 1100 and 1220 hrs, with 2.6 mm in the hour before the incident. The ATIS reported runway wet, wind 230/11 kt, visibility 6,000 metres, rain. Post-incident observation at 1550 hrs showed wind 270/14 kt, varying, with the same visibility and rain. Upper wind structure was complicated by a trough, and a 25 kt wind shear existed between 1,000 ft and the surface. The commander recalled that the FMS indicated 240/40 kt at 1,000 ft while ATC gave surface wind 270/12 kt. A previous landing aircraft reported no significant windshear, but a torrential downpour began about 30 seconds before the Fokker touched down, confirmed by an air traffic control assistant.
Airfield and runway details
Southampton's Runway 20 is 1,723 metres long with a displaced threshold of 45 metres, providing a declared landing distance of 1,605 metres. The runway has a slight downslope of 0.23% and a brush finished concrete surface. While in good condition, the surface had a tendency to slow drainage of standing water in heavy rain, which had imposed operating penalties on modern jet aircraft. Following the incident, the airport authority initiated transverse grooving of the runway to improve water run-off, completed in April 1999. The runway end is followed by a 60-metre paved area, a 90-metre safety area, and a soft ground arrester bed. The ILS and PAPIs were serviceable and met required standards.