The Federal Aviation Administration and an airline spokesman say U.S. Airways Express flight 4507 from Philadelphia to New Haven, Conn., was diverted to the Islip Town airport Friday afternoon as a precaution.
FAA spokeswoman Arlene Salac says the pilot reported electrical problems with the aircraft after the lightning strike.
The plane had originally been scheduled to land at 2:30. It was unclear when it was diverted.
U.S. Airways spokesman Andrew Christie says the Bombardier Dash 8 has been taken out of service and is being evaluated. Passengers were bused to New Haven.
The flight was operated by Piedmont Airlines, a subsidiary of U.S. Airways.