Thanks Bonger
Information from the NTSB letter to FAA dated January 27:
Snow began to fall in the area surrounding MDW about 5 hours before the accident. While the flight was en route and holding to land at MDW, the flight crew obtained updated weather information and runway braking action reports from air traffic control. On the basis of this information, the flight crew planned for fair braking action on landing on runway 31C. The runway was last cleared and treated about 45 minutes before the accident. About 30 minutes before the accident, airport ground personnel performed a runway friction measurement, which indicated that the runway friction was "good". About 1/8 to 1/4 inch of scattered snow was on the runway when the airplane touched down.
Under such circumstanses, would it not be more correct to use contaminated performance data
THIN CLUTTER in stead of wet performance data
WET-FAIR?