WASHINGTON -- A proposal aimed at stemming crashes of air ambulances would require that the helicopters carry alarms that would warn pilots if they are close to hitting the ground, the Federal Aviation Administration announced Wednesday.
The alarm is part of a computerized device that can track every hill and radio tower in the world, warning pilots when they get too close to danger. The Terrain Awareness Warning System (TAWS), which is credited with preventing dozens of accidents on jets, would cost about $100,000 per helicopter.
Between December 2007 and October 2008, 13 air ambulance accidents killed 35 people.
The FAA has pressured air-ambulance operators to improve safety and add devices such as TAWS, but so far the effort has been voluntary. The National Transportation Safety Board, which investigates aviation accidents, had criticized the FAA for not moving more quickly.
"We recognize that relying on voluntary compliance alone is not enough to ensure safe flight operations," John Allen, director of the FAA's Flight Standards Service, said at a Congressional hearing on safety in the industry.
There are more than 800 air-ambulance helicopters in the U.S.
The industry is moving to equip the devices. More than 40% of operators have begun installing them on their fleets, the FAA estimates. Honeywell, the leading manufacturer of the devices, has sold 200 to air-ambulance companies, spokesman Bill Reavis said.
Allen said the agency expects the rule to go into effect in 2011.
The aviation agency would also require that helicopters ferrying patients be equipped with flight recorders similar to the black boxes on airliners, Allen said. The recorders are designed to help investigators determine why helicopters crashed.
The FAA would add more rigorous tests for helicopter pilots to ensure that they can handle the types of poor weather and dark conditions that have led to many crashes, Allen said. Operators would have to calculate the risks of each flight before departing, he said. If the risks -- such as poor weather or a difficult landing zone -- are too high, the flight would be canceled.
The House Aviation Subcommittee heard testimony Wednesday from a divided air-ambulance industry. Many small- and medium-size operators want air-ambulance companies to have stricter oversight by state agencies. But larger operators argued that state oversight would create confusing standards in different regions of the country.