US Airways spokesman Todd Lehmacher says Flight 4321 from Elmira, N.Y., landed safely on Tuesday afternoon.
Lehmacher says crew members reported seeing a possible flare as the plane came in around 1:40 p.m.
Air traffic control transmissions obtained by Action News began:
Pilot: There's a flare back there, 500 ft Piedmont 4321 on final.
Tower: There's a what? I missed it, sorry.
Pilot: It looked like a flare that was shot up.
Tower: You said there was a flare being shot up say at you?
Pilot: Yeah, it was probably wasn't more than 50 feet off our right wing, it looked like a flare gun, it had a little canister that exploded right next to us.
Tower: Ok. Wow
Philadelphia police say they received a 911 call reporting someone had shot off a flare gun at an intersection near the airport. Officer Jillian Russell says officers went to the intersection but found no evidence of it.
Airport spokeswoman Victoria Lupica says the crew's report led to a 30-minute closure of one runway.
Lehmacher says the plane was carrying 34 passengers and three crew members.
The plane landed safely and no injuries were reported.