A US Airways Express airliner slid down a runway on its nose during an emergency landing without its nose gear.

No injuries were reported.

The Philadelphia-bound deHavilland Dash-8 turboprop, operated by Piedmont Airlines, had taken off from Allentown at about 8:20 a.m. with 35 passengers and three crew members on board, according to officials of the airline and Philadelphia International Airport.

Before the scheduled landing at Philadelphia, the crew got an indication that the landing gear was not down and did a flyover to confirm that the nose wheels had not deployed, airport spokeswoman Victoria Lupica said.

Fire crews spread foam on the runway as a precaution before the landing at about 9:20 a.m.

The plane skidded down the runway on its nose, but there was no smoke and no fire, Lupica said.

Passengers were taken to the terminal by bus.

The cause of the problem was being investigated, said Tempe-based US Airways spokesman Morgan Durrant. The Federal Aviation Administration and the National Transportation Safety Board also were investigating, Lupica said.

Lupica said the airport had to be closed for about 25 minutes.

The airport reported some flights delayed more than two hours around midday while the plane remained on one of the four runways. That runway reopened in early afternoon and most flights were running on time, Lupica said.