Certainly the manufacturers will have some limited data for severe water contamination ... ie a simple flooded runway situation... as the normal exercise for engine ingestion tests sees the aircraft being run through a big controlled puddle from which some drag data can be obtained in addition to the prime test function.
The real world problem is real world variability... like all this performance stuff... how deep is the water and what is the variation over the runway etc ... in the case of a contaminated situation (slush and snow) the density and depth estimations are a bit finger in the windish.
What one does in the real world situation, then, is fraught with a degree of optimism or pessimism according to one's, and one's company's, views.
My views are coloured by the thoughts that the company ought to prescribe in the OM its requirements and preferences for the guidance of crews. Over and above this, there is always the crew's option to apply the recommended practices in a more conservative manner .... someone has to assess the depth etc of the contaminant ... and ultimately, if considered appropriate, this might include deferring the departure or diverting/holding in the case of an arrival ... presuming, in the latter case, you have the luxury of spare fuel.
I think the main thing is to be reasonably consistent and sensible so you have something to hang your hat on at the enquiry and the chief pilot has something with which to fend off the accountants when they come looking for a hide to pin to the wall after the flight is delayed or cancelled ...
As to legality ... isn't that what the judge decides after everyone has had all the time in the world to review the decision you made in a few seconds or minutes ? ... and you have been made to look a total idiot in the witness box during the said review of the said decision making process ?
Last edited by john_tullamarine; 17th May 2002 at 01:38.