Off the top of my head eps they took planes:
ASU
Toy Story [the ep at the end of S4 where they show up and M/J want to go to a hotel and Lois tries to tell Clark why and he's like 'but they're my *parents*!/whine/'
Ides of Metropolis
Other eps they were there but I don't remember specific travel info include:
ATAI
Whatever the ep is where Jonathan does everything Martha does and Martha plays chess and takes naps and Jonathan orders Chinese and tries to pretend he makes it and they call Lois family - S2
Ugh - that's all I'm coming up with off the top of my head.
