F100, Southampton UK, 1998
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|On 24 November 1998, a KLM uk Fokker 100 overran runway 20 at Southampton after a late and fast daylight touchdown in rain was followed by poor braking. The Investigation found that the assessment of the runway as ‘wet’ passed by ATC prior the incident was correct but that sudden heavy rain shortly before the aircraft landed had caused a rapid deterioration to somewhere between ‘Wet’ and ‘Flooded’. Slow drainage of water from the runway was subsequently identified and the runway was grooved.|
|Actual or Potential
|Human Factors, Runway Excursion, Weather|
|Flight Conditions||On Ground - Normal Visibility|
|Type of Flight||Public Transport (Passenger)|
|Actual Destination||Southampton Airport|
|Take off Commenced||Yes|
|Location - Airport|
|Tag(s)||Approach not stabilised|
|Tag(s)||Inappropriate crew response - skills deficiency,|
Procedural non compliance
|Tag(s)||Overrun on Landing,|
Excess Water Depth"Excess Water Depth" is not in the list (Overrun on Take Off, Overrun on Landing, Directional Control, Excessive Airspeed, RTO decision after V1, High Speed RTO (V above 80 but not above V1), Unable to rotate at VR, Collision Avoidance Action, Parallel Approach Operations, Late Touchdown, ...) of allowed values for the "RE" property.,
|Damage or injury||Yes|
|Causal Factor Group(s)|
On 24 November 1998, a Fokker F100 being operated by KLM uk on a scheduled passenger flight from Jersey, Channel Islands to Southampton overran runway 20 at Southampton after a late and fast daylight touchdown in heavy rain but normal ground visibility was followed by poor braking response. The aircraft stopped between the end of the paved surface and an arrester bed and sustained only minor damage. None of the 101 occupants were injured and were able to disembark the aircraft via steps.
A Field Investigation was carried out by the UK AAIB. It was noted that the ILS approach had been made to a runway reported by ATC to be ‘wet’. Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR) data were downloaded and confirmed that only medium auto brake and idle reverse had been selected. Ground spoiler deployment had been normal.
For reasons that were not established, the final approach was found to have been unstable, with airspeed and thrust particularly variable and the subsequent touchdown both late and ‘soft’, leaving only abut 1000 metres of paved surface remaining. It was noted that about 30 seconds before touchdown, heavy rain had suddenly begun to fall and it was estimated that, given the poor drainage characteristics of the runway, it was likely to have been in a condition somewhere between ‘wet’ and ‘flooded’. Such conditions would have been conducive to aquaplaning which appeared to have occurred.
It was noted that “The commander had experienced no retardation problem during the (earlier) landing in similar conditions at Jersey and had accepted the Southampton runway condition as ‘Wet’. He did not appear to have (had) any doubts about stopping the aircraft in the runway remaining after (the late) touchdown and consequently showed no sense of urgency in applying maximum retardation. Nor had he considered carrying out a missed approach, probably for similar reasons, although this would have been an available option”. It was concluded that “Despite the fact that it may have had limited effect, once the decision to continue the landing had been made, it would have been prudent to have over ridden the auto-brake system, applied full braking and selected maximum reverse thrust immediately after touchdown.”
In the light of this and other similar instances of extended stopping distances when the runway involved had been reported as ‘wet’, the Investigation noted that the Airport Operator had subsequently taken urgent steps to groove the runway as a means to improve drainage of water from the surface during periods of high rainfall intensity.
The Final Report of the Investigation AAIB Bulletin No: 6/2000 Ref: EW/C98/10/3 was published in June 2000. No Safety Recommendations were made.