Pilots Told to Check for Ice on Wings

Federal safety officials said Wednesday that they were sending a letter to pilots warning them to run their hands along their aircraft’s wings before takeoff to make sure tiny amounts of ice hadn’t formed and increased the risk of an accident.

The National Transportation Safety Board said the unusual alert, aimed at pilots of smaller planes, stemmed from discussions about icing during the investigation of the Nov. 28 crash in Montrose, Colo., that killed the 14-year-old son of NBC Sports Chairman Dick Ebersol and two other people.

NTSB spokesman Ted Lopatkiewicz said the accident raised the issue, although investigators hadn’t determined that icing caused the crash.

“We know the Ebersol crash was in icing conditions, but we don’t know it was an icing incident at this point,” Lopatkiewicz said.

Ice on a wing disrupts the flow of air, which can cause the wing to lose its lift and the plane to dive.

The safety board said that most pilots didn’t know that a thin layer of frost or ice could have consequences as severe as those caused by much larger ice accumulations.

“Fine particles of ice or frost, the size of a grain of table salt and distributed as sparsely as one per square centimeter over an airplane wing’s upper surface, can destroy enough lift to prevent that airplane from taking off,” the NTSB said.

The safety board said in its letter that pilots might not understand the risk posed by a nearly imperceptible amount of ice.

“From an aerodynamic point of view, there is no such thing as ‘a little ice,’ ” the board’s letter said.

“No amount of snow, ice or frost accumulation on the wing upper surface can be considered safe for takeoff,” the board said.

The safety board said the only way to determine if there wasn’t any ice on the wing was to touch it.

The alert is aimed at smaller planes, such as corporate jets, regional jets and private aircraft.