PPRuNe Forums - View Single Post - TAM A320 crash at Congonhas, Brazil
View Single Post
Old 26th Jul 2007, 02:05
  #532 (permalink)  
PEI_3721
 
Join Date: Mar 2006
Location: England
Posts: 997
Likes: 0
Received 6 Likes on 3 Posts
RobertS975, There are almost certainly specific aspects of this accident that would answer why this flight overran and others did not. However, a simple statistical review of operations on a wet runway with the same type, wt, etc, would show a spread of landing distances. This is normal operation and why safety margins are applied (factored landing distances) – a principle of being safe, apply a margin.
On a wet runway, particularly ungrooved, the spread of landing distance could increase very quickly with small, seemingly insignificant changes in the conditions e.g. a small change in wind direction that prevents water drainage, changing the runway from wet to flooded.

lomapaseo, I think that the general changes called for were those applying to human behaviour – which is difficult.

‘World standards’ – this is one of the many problems in the industry. Generally the main regulators are in agreement for the certification aspects of wet / dry runways, but the systems diverge with ‘contaminated’ and the operational application of the rules. Note the Chicago Midway accident and the weak FAA response re verifying runway condition before landing vs the European ‘contaminated ops’ rules. (The FAA does note the European position but only as guidance).

Safety margins are open to operator judgement – safety management. A survey of this runway may well have concluded a reduced level of safety (judgement), but who would be the first operator to add a margin?
Well done to those pilots who don’t land in the wet (good safety margin), but why don’t the managers support this action – lack of personal standards?
PEI_3721 is offline