I am surprised that these pilot landed at the wrong airport.. these guys cant be going to Padang for the first time, no way... Besides the route from Medan to Padang (W11) would have taken you to the airport or upon reaching Padang the controllers would have directed you along the shoreline which both cases you would see the Padang airport on the left handside which has a runway 2750m (9022ft) long.., then directed to a famous waypoint in Padang BAYUR..at 5000FT for a ILS approach.
Or the captain.. decided to grow a braincell...
Minangkabau International Airport to -0.873723, 100.351324 - Google Maps