What is the difference between transferring venue and forum non conveniens?

Hypo 1: Bob, a resident of California, owns an airplane manufacturing facility in California. He ships airplanes around the world. One day, one of Bob's airplanes is involved in a crash in Scotland involving Scottish citizens. The survivors and victims of the crash bring a suit against Bob in a California federal court. Result: Bob would likely be successful in invoking forum non conveniens because it doesn't make sense to hear the case in a California federal court even though jurisdiction is proper. Bob would argue that this case involves Scottish citizens, flying in Scottish airplanes, who experienced a crash within Scottish territory. The evidence of the crash is in Scotland, as is the evidence of whatever may have caused the crash. Further, the witnesses are in Scotland, as are the victims and their families. It would be super inefficient to try to hold the trial in California when everything about the case is in Scotland. Moreover, Scotland has an interest in pursuing justice for their citizens, and so it is unfair to deprive their court system of an opportunity to hear the case. On the flip side (and you will often have to argue the other side), the Scottish victims may want to have the case heard in a California federal court because there is an opportunity to have higher damages awarded. Thus, the court will hear these arguments and, in the end, likely grant forum non conveniens, which means that the case is dismissed but the parties are free to pursue it in another court with jurisdiction, like in Scotland. Note: the reason that the court can't transfer the case to Scotland is because Scotland and California are completely different court systems with no ability to transfer a case between them. There's no link between the two systems to move one case from another, so it must be brought again by the plaintiffs, starting over from scratch.

Hypo 2:Bob, a resident of California, owns an airplane manufacturing facility in California. One day, one of Bob's airplanes is involved in a crash in Hawaii involving Hawaiian citizens. The survivors bring a suit against Bob in a California federal court. Result: This is basically the same hypo as Hypo 1, but note that now we are in the United States' federal court system, which means rather than invoking forum non conveniens, Bob can opt for a transfer of venue from one federal court in California to another proper one within Hawaii. Note: Another common trick on exams is to talk about whether it's possible for a party bringing a suit in state court to transfer that suit into a different state court. Different state court systems, like the foreign country example in Hypo 1, do not have the ability to transfer cases between themselves at the state level, which means forum non conveniens would be the option to pursue, not transfer of venue.