If I am visiting Israel for Shavuot, can I take a flight which leaves on the second day and lands somewhere else about one hour before chag ends in that place, and remain in the airport until this time?

Shalom, Thank you for your question. There are two issues involved here – firstly, if, as a visitor to Israel you need to keep one or two days Yom Tov. Secondly, if a person is keeping only one day Yom Tov, are they allowed to fly into second day, and land in an airport on second day Yom Tov when it is a festival day there. In relation to the first question – the normative halacha is that a person who has a permanent residency outside Israel, and is merely visiting Israel as a tourist, usually keeps two days even when they are visitng Israel. However, there are opinions that hold that everyone who is in Israel keeps only one day, no matter where they have their permeant residency. There is much debate on this issue, and it is dependent on many factors. And, of course, if you do keep two days, your question does not even begin – you cannot get on the plane on second day if you are keeping two days of Yom Tov. (Because of this, it sounds from your question that you already have a ruling to keep only one day here – and so we will continue to answer you based on the assumption that you have received such a ruling from a Rabbi for your particular case). A person keeping one day may board an airplane in Israel in the day after Yom Tov (what would be second day outside Israel) and fly out of the country. When they land in a city that has a Jewish community (nearly all cities one can fly to from Israel – including Dubai!) one may leave the plane and stay in the airport until night, when the second day ends. In the airport one does not have any restrictions of second day Yom Tov – but one may not leave the airport at all, as outside the airport the laws of second day apply. Blessings.