The Miqat boundaries (designated entry points for ইহরাম) apply whether you travel by land or air — passing them without being in ইহরাম when you intend হজ্জ or উমরাহ is not permitted. Since modern flights are fast, preparation is key. The practical approach is to perform গোসল (ritual bathing) and grooming at home or the departure airport, then change into your ইহরাম garments either before boarding or in the airplane lavatory before the Miqat is reached.
Most airlines operating হজ্জ and উমরাহ flights announce when the plane is approaching the Miqat boundary. If your airline does not make this announcement, use a GPS-based Miqat alert app (ইহরামOS includes this feature) or research your flight path to estimate the timing. Common Miqat points for air travelers include: Dhat Irq for those coming from the east, Yalamlam for those from the south, and Al-Juhfah for those from the north and west.
Once you are in your ইহরাম garments and approaching the Miqat, make your intention (niyyah) in your heart — specifying whether you are performing হজ্জ, উমরাহ, or both — and begin reciting the তালবিয়াহ: 'Labbayk Allahumma labbayk...' If you realize you have passed the Miqat without entering ইহরাম, the majority of scholars say you must either return to the Miqat (if possible) or pay a fidyah (sacrifice a sheep in মক্কা মুকাররমা). To avoid this situation, it is safest to enter ইহরাম well before the estimated Miqat crossing.