My opinion:
1. As soon as Purim starts on the evening of March 7, you are obligated in mitzvos hayom. Do everything you can to fulfill these mitzvos (megillah at night, the following day, seudah, mishloach manos, matanos l’evyonim). Being in the airport or on the plane may make it difficult, do your best. It has been done before by many people.
2. If you arrive in Yerushalayim before the start of Purim there, (15 Adar, the evening of March 8) you are obligated once again to fulfill these mitzvos, even if you have already done them on 14 Adar.
3. You may not delay your Purim ( not observe 14 Adar) on the assumption that you will get to Yerushalayim before the evening of March 8.
4. In Efrat, Purim is 14 Adar.