That would include airline claims that the 25-minute window can amount to a total ban on flights at some congested airports.
At overcrowded JFK, the average taxi-out time for planes taking off last year was 33 minutes, according to the U.S. Bureau of Transportation Statistics. The average flight taxied for 30 minutes at Newark Liberty International, 27 minutes at LaGuardia and 20 minutes each at Hartsfield-Jackson Atlanta International and O'Hare International in Chicago.
The United Parcel Service said its own research indicated that anti-icing fluids protect planes from ice pellet buildup for much longer than the 25 minutes suggested by the FAA.
"Obviously, everyone wants to be conservative," said UPS spokesman Mark Giuffre. "But," he added, "there are some forms of ice pellets and precipitation where we think there are operative conditions ... We still feel like there's more opportunity (to fly)."