53. The SEA-PDX route is served by just four airlines. Between them they operate seven different aircraft types on this route – however only one type offered between SEA and PDX is common to each of the four carriers. Please identify each of the four airlines that fly SEA-PDX and the single type of equipment common to each one on this route.
HINT: WA, UA and NW have been identified. We're looking for one more airline and the common aircraft type...
Per miniliq: Seems like West Coast (WC) Airlines belongs on this list, but I have no suggestion for the common aircraft type.
West Coast did indeed fly between Seattle and Portland, however they were using Seattle's Boeing Field (BFI) rather than SEA.
Per jrl767: I'm gonna throw out a real wild guess ... Pacific Northern ... the common aircraft was the Boeing 720
Correct! To his credit, JL had mentioned this possibility earlier but ultimately went with a different aircraft. Well done, J! ^