President Obama departed Philadelphia Sunday night on a backup aircraft because the primary aircraft had a mechanical problem with one of its wing flaps, the White House said in a statement, Philly.com reported.
Air Force One is the designation for whatever aircraft is carrying the President. Standard procedure is to have two aircraft on each trip in case of a problem. In this situation, Obama was traveling on a C-32, which is the military version of a Boeing 757.
Principal Deputy Press Secretary Eric Schultz said in a statement Sunday, relayed through the White House press pool that, "While in Philadelphia, we have transferred to a backup airplane due to a minor mechanical problem with one of the aircraft's flaps. This switch to a backup C-32 will not affect our schedule."
Obama was in Philadelphia to speak at a rally at Temple University for Tom Wolf, who is running for governor of Pennsylvania.