Radar problems briefly delay O'Hare flights

Radar problems at O'Hare International Airport caused delays for planes arriving late this morning.

Difficulties in transmitting information between the radar system and air traffic controllers at the O'Hare tower caused officials to switch to a backup program based out of Tinley Park, the Federal Aviation Authority reported.

The glitch occurred around 11:05 a.m. but was fixed an hour later, the FAA said.

Authorities are still trying to figure out what caused the mixup and how many flights it affected. The arrival rate at O'Hare dropped from 96 aircraft an hour to 72 an hour, officials said.