SkyWest Airlines and the Federal Aviation Administration appeared to give conflicting explanations for why three people passed out mid-flight Wednesday, forcing a plane to make an emergency landing.

With nearly 80 passengers on board, SkyWest Airlines Flight 5622 -- operating as United Express on behalf of United Airlines -- was 40 minutes into its flight from Chicago to Hartford, Connecticut, when a passenger in the middle of the plane began to lose consciousness.

The pilot feared a potential cabin pressure problem and dropped the plane to get breathable air, according to the FAA.

But the Utah-based regional airline says there are no indications of a pressurization problem on the plane or a problem with the plane's equipment, adding that there were no cockpit warnings and the overhead oxygen masks never dropped.

Marissa Snow, a spokeswoman for SkyWest Inc., told The Associated Press today inspections show "absolutely nothing wrong with the aircraft."

Eric Weiss, spokesman for the National Transportation Safety Board, said, "We're trying to understand the circumstances before we decide on what, if any action, we would take," according to the AP.