All perfect praise be to Allah, The Lord of The Worlds; and may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
A person intending to offer Hajj or Umrah shouldn`t pass the Meeqat of his country or any other Miqat that he passes by without assuming Ihram. This is indicated by the Hadith reported by Ibn Abbas who said: " Allah's Messenger (PBUH) had fixed Dhul Hulaifa as the Miqat for the people of Medina; Al-Juhfa for the people of Sham; and Qarn Ul-Manazil for the people of Najd; and Yalamlam for the people of Yemen. So, these (above mentioned) are the Mawaqit for all those living at those places, and besides them for those who come through those places with the intention of performing Hajj and `Umra and whoever lives within these places should assume Ihram from his dwelling place, and similarly the people of Mecca can assume lhram from Mecca." {Agreed upon}.
Accordingly, the person who lives beyond the Miqat isn`t permitted to pass it without assuming Ihram, and he isn`t allowed to assume Ihram from Jeddah as well because it is situated inside the Meeqat. Moreover, the person intending to offer Hajj or Umra is allowed to put on his Ihram clothes while at their dwelling place or aboard the plane, then make the intention to assume Ihram for Hajj when reaching the Miqat as shall be alerted to by the captain or the flight guide.
However, if he made the intention to assume Ihram while boarding the plane, to be on the safe side, then it is permissible. And Allah knows best.