TCAS To The Rescue

FAA investigators want to know why two passenger airliners flew unacceptably close ito each other in the skies over Iowa this week... and they're taking a close look at operations at Chicago Center.

The Chicago Tribune reports a United Express regional jet flying to O'Hare International from Lincoln, NE came within 1.79 miles horizontal, and 900 feet vertically of a Northwest 757 bound for Detroit from Denver. The RJ had been directed by a veteran controller to make a descending turn over Dubuque, IA, which put the jet at the same altitude as the 757.

Proving the value of onboard collision avoidance systems, TCAS units on both planes directed the aircraft away from each other. Pilots of the Northwest plane were told to climb above FL300, and the United Express plane was directed to take evasive action as well.

Toby Hauck, vice-president of the National Air Traffic Controllers Association at the Aurora, IL control facility, said the assistant controller on duty was not well-versed on how to use new separation technology in place at the center.

"The planes were closing in on each other and the controller took action to keep the planes separated," said Hauck. NATCA has said before the new Traffic Management Advisor is prone to error, and that it has caused problems at other airports.

FAA spokesman Tony Molinaro disputed that account, however, maintaining the controller was not working with the new system, which is used to sequence planes into busy airports.

"The controller lost track of where the planes were and they lost separation," Molinaro said, adding the investigation is continuing.

FMI: www.faa.gov, www.natca.org