What should one do who forgot the Ihram garments and will pass over the Miqat while on the airplane?

Whoever passes by one of the Miqats, intending to perform Hajj or Umrah, must enter into a state of Ihram from the Miqat. Ihram is the intention to enter into the ritual, and it does not require wearing the Ihram garments, but merely the intention. One arriving by air or sea must enter Ihram when they are abreast of the Miqat.

Whoever passes the Miqat without entering Ihram intentionally is sinful. If it was due to error, ignorance, or forgetfulness, there is no sin upon them, but they must return to the Miqat and enter Ihram from there. There is no compensatory sacrifice (Dam) required according to the Shafi'is, Hanbalis, and Malikis. If they are unable to return, they should enter Ihram from their current location, and a Dam (slaughtering a sheep) becomes obligatory upon them.

Whoever enters Ihram from the Miqat without wearing the Ihram garments due to inability, must wear them after disembarking. They are then subject to an expiation (fidyah) with a choice: fasting for three days, feeding six needy persons, or slaughtering a sheep.