On November 21, DAL264 had just departed KJFK and was climbing through about 11000 feet when they told ATC that they had to stop the climb at 12000 while they started some troubleshooting. The flight crew eventually declared an emergency because of fumes in the cabin and decided to return to KJFK. They asked for the emergency equipment to standby because they were going to perform an overweight landing. The aircraft landed safely a short time later and then taxied off the runway. The emergency crews checked out the brakes to make sure they weren't overheating. The aircraft eventually taxied back to the ramp.
https://www.flightaware.com/live/flight/DAL264/history/20241121/0350Z/KJFK/KJFK
