KLM and Martinair operate the Mad Dog (MD11) to Quito almost daily.With its high approach speed it's quite a challenging approach for a MD11.Every pilot needs a yearly check to Quito with an instructor.Recently KLM headoffice informed if there could be a regular runway cleaning of all the rubber deposit in the two touchdown zones, since 35/17 is "slippery when wet" to say the least.But without spoiler deployment........