Barack Obama isn't going to North Carolina today after all.

His plane had to make an unscheduled landing in St. Louis due to a mechanical problem.

The charter was taking the Democratic presidential candidate to campaign events in Charlotte. A cockpit announcement said the plane experienced a flight-control problem after take-off from Chicago.

Passengers felt the plane dip briefly. But the unexpected movement did not cause visible alarm for the frequent fliers on the plane.

Obama told reporters on board that the stopover was to "spice things up a little bit."

The Illinois senator and a small entourage eventually left the plane and the tarmac to await a flight maintenance check at a local hotel. The North Carolina trip has been postponed until a future date. Obama is instead delivering his remarks on the economy to the reporters traveling with him.