Comair is moving to install ice detectors on all 39 of its Embraer EMB-120 commuter planes even before the devices are required by the Federal Aviation Administration, a spokeswoman said Tuesday.
"We see this as a precautionary step and are moving to be in compliance," said Meghan Glynn, Comair spokeswoman.
Icing is suspected as a factor in the crash of a Comair Embraer EMB-120 Jan. 9 that killed all 29 on board. The turboprop was en route from Cincinnati to Detroit when it stalled in a snowstorm and crashed in a field in Monroe, Mich.
Ms. Glynn said the 50-seat Canadair Regional Jets, which make up the rest of Comair's fleet of 89 aircraft, already have similar ice detection sensors.
Icing, or ice build-up on the wings, is a particular problem for turboprop aircraft because they fly at slower speeds and lower altitudes than jets. When ice builds up on wings, it can disrupt air flow, robbing an airplane of the lift that keeps it in the air. On Tuesday, the FAA published proposed new rules that would require operators of the Brazilian-built turboprop to install ice detection sensors within six months and implement new flight procedures within 30 days after a 45-day public comment period expires.
The detectors, which cost about $18,000 per plane, are made by B.F. Goodrich's Aircraft Sensors Division in Minneapolis, Minn.
The FAA estimated the cost of installing the detector kits on the 220 EMB-120s flying in the United States at $4 million.
The sensors are separate from aircraft deicing equipment. On the EMB-120s, that system consists of pneumatic "boots" on the wings and tail that the pilot can inflate to break up ice.
Manuel Monteiro, assistant vice president for engineering liaison and safety at Embraer's U.S. office in Fort Lauderdale, Fla., said the sensors proposed by the FAA consist of a 2-inch metal probe on the nose of the aircraft. The device vibrates at a predetermined frequency, and if ice builds up, that frequency changes, setting off a warning light in the cockpit.
"This gives the pilot some additional information to alert him if there's a problem," he said.
Currently, the only way EMB-120 cockpit crews can detect icing is visually.
Ice detection sensors are nothing new on larger aircraft like the Boeing 767 and 747 and even the larger Embraer 145, but this is the first time the FAA has moved to require them on the 30-seat EMB-120s. Don Zochert, FAA spokesman, said the new rules were the result of the agency's ongoing review of pilot reports and aircraft service data. But he said the January Comair crash "intensified" the agency's review.
The other part of the FAA's proposal covers pilot procedures, such as when they should deploy deicing equipment and the proper air speeds to maintain under various conditions.
The proposed new rules come only a year after the agency gave the EMB-120 a clean bill of health after testing its airworthiness under icing conditions. Those tests came after icing contributed to the crash of another type of turboprop, an ATR-72, in Roselawn, Ind., 2 1/2 years ago.
Those tests did result in an FAA rule that all turboprop pilots make visual checks for ice and avoid flying in icing conditions when possible.
A spokesman for the National Transportation Safety Board, which is investigating the Comair crash, said the agency was studying the FAA's new rules for the EMB-120, but had no other comment.
The NTSB, which last week released transcripts of the Comair cockpit voice recorder, isn't expected to complete its investigation until the end of the year.
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