Route notes
Why this routing works
The routing logic here is a clean westward sweep from Philadelphia across the Pacific Rim. PHL connects to LAX via American Airlines, and LAX serves as the transpacific launch point for the ~16h Qantas or United flight to Melbourne. The Australia-to-Asia segment follows the Cathay Pacific corridor — MEL-HKG in the evening positions travelers perfectly for a morning arrival into Hong Kong, which is the entry point for the East Asia portion of the trip.
Singapore is the pivot point from Asia to Europe. Singapore Airlines operates SIN-FRA direct at approximately 13.5 hours — one of the world's longest nonstop routes and a reliable single-leg connection from Southeast Asia to the Lufthansa network. This eliminates the need for a Middle East connection, which is the alternative on most Asia-to-Europe itineraries. Frankfurt then provides the short hop to Porto via TAP or Lufthansa.
The Porto-to-Lisbon surface sector is a deliberate routing choice rather than a workaround. The Alfa Pendular train between the two cities runs every two hours and takes approximately 3 hours — faster door-to-door than flying once airport time is accounted for. TAP Air Portugal then operates LIS-PHL direct (~8.5h), one of the only transatlantic routes serving Philadelphia without a hub connection, closing the loop efficiently.