US Airways spokeswoman Valerie Wunder says Express Flight 2588 from Knoxville, Tenn., to Philadelphia declared an emergency before landing shortly after 5 p.m. Friday.
Airport spokeswoman Victoria Lupica says the plane landed safely but didn't taxi to the gate. She said 52 passengers and four crew members were evacuated onto the runway.
Lupica says the passengers and crew members boarded buses and were driven to their gate.
It's not immediately clear what caused the smoke in the cockpit. No injuries were reported.
US Airways Group Inc. is based in Tempe, Ariz.
