On Dec 20th at around 10:45PM local time, Lindbergh 3667 declared an emergency shortly after takeoff and returned to KORD. They had a gear issue where it made a "loud noise" when retracted. They actually went as far as Chicago Center (123.82) before there was any mention of a problem. The attached audio clip picks them up on Chicago Departure. The segment on Chicago Center (123.82) is not available; no coverage there from liveatc. It looks like the flight first notified ATC of the gear problem while they were talking to Chicago Center. Interesting that they would wait that long...the gear is retracted long before they get to that point, usually right after takeoff and I believe when a positive rate has been achieved...
Anyway, here's the audio...
Ron