President Barack Obama had to switch planes in Philadelphia on Sunday night because of a minor mechanical issue with the aircraft, the White House reportedly said. Obama was in Philadelphia for a pre-election rally.

Obama was returning to Washington after traveling to Pennsylvania for a campaign rally ahead of Tuesday’s midterm elections. After the minor glitch was discovered, Obama and other people travelling with him were transferred to a smaller Air Force One plane. He reportedly had travelled to Connecticut earlier on Sunday, according to The Associated Press.

"While in Philadelphia, we have transferred to a backup airplane due to a minor mechanical problem with one of the aircraft's flaps," Eric Schultz, a White House spokesman reportedly said. "This switch to a backup C-32 will not affect our schedule."

Air Force One is a term used to identify any airplane used by the president, usually a Boeing 747 jet.

Obama's appearance in Philadelphia was reportedly part of an eight-state campaign tour over the past couple of weeks. He arrived in the city with businessman Tom Wolf, who is running for governor of Pennsylvania, and reportedly addressed about 5,500 people.

Obama reportedly summed up his message by saying: “You've got to vote!"