CLOSE CALLS FOR O'HARE INTERNATIONAL AIRPORTS

The almost-completed first phase of O'Hare International Airport's expansion had close calls that could have resulted in fatal airplane crashes, according to a Tribune investigation of incidents filed with the Federal Aviation Administration.

As the Chicago Department of Aviation prepares to start the next phase of rebuilding at O'Hare next month, the reports on the incidents spotlight the challenges of conducting a complicated airport modernization program on a busy airfield. They also show how an ever-changing list of alerts to pilots, air traffic controllers and construction crews increases the opportunity for serious mistakes, including planes taking off and landing on closed runways. CHICAGOTRIBUNE