WASHINGTON, D.C. — Aircraft manufacturers would be required to show that small airliners can fly safely in certain icy weather conditions that have proven deadly in the past under a rule proposed Tuesday by the Federal Aviation Administration.
FAA officials said they want to expand the certification standards for new airliners weighing less than 60,000 pounds, a category that includes small transport jets and turboprop planes. The planes would have to be able to fly safely in rain that falls as liquid but freezes instantly when it hits an aircraft’s surface. The rain can form ice ridges that change the shape of wings, making the plane difficult to handle.
Complying with the new rule will cost aircraft and engine manufacturers an estimated $71 million, FAA said.
Safety officials have urged the change in certification standards since a regional airline crash near Roselawn, Ind., in 1994 that took 68 lives. In that case, pilots lost control of a turboprop while waiting to land in freezing rain after ice ridges formed on the aircraft’s wings.
That particular weather phenomenon, known as “super-cooled liquid droplets,” was little understood at the time.
“These regulations will help ensure future aircraft can operate safely in some of the toughest icing conditions,” FAA Administrator Randy Babbitt said in statement.
A recommendation to expand aircraft certification standards to specifically include freezing rain has been on the National Transportation Safety Board’s list of most wanted safety improvements for years. However, FAA’s proposal applies only to future aircraft. NTSB has recommended that the safety requirements be applied to planes currently in use, as well.
“It’s difficult to make certification requirements retroactive because then you have to go back and recertify all those aircraft, which is a formidable task,” FAA spokesman Les Dorr said.
The proposed rule would also require new aircraft be able to perform safely in certain kinds of storm clouds that can create ice crystals deep inside jet engines, causing them to temporarily shutdown.
NTSB Chairman Deborah Hersman complained at a congressional hearing earlier this year about FAA’s slow progress on the issue, noting that the board made its recommendations 13 years ago.
Although FAA has proposed regulations, the agency often takes months or years to make its proposals final.