Question: If the sun set upon a person and the Mu’azzin called the Adhan while he was in the airport and he broke his fast. Then after the plane took off, he saw the sun, should he fast?
A:Our answer to this is that he is not required to because the time for breaking the fast came while they were on the ground.
So, the sun set while they were in a place in which it set, and the Messenger of Allah (peace be upon him) said: “When night falls from this side, and the day vanishes from this side, and the sun sets, then the fasting person should break his fast. ”
So, if a person, upon whom the sun set, broke his fast while he was on the ground in the airport, then his day has ended. If his day has ended, then he is not obliged to fast except on the next day.
So, based on this, it is not necessary to fast in these circumstances, because breaking the fast was only according to a legal evidence, and it is not required to fast except based upon a legal evidence. And Allah knows best.
– Sheikh Muhammad Bin Salih Al-‘Uthaimeen, Islamic Verdicts on the Pillars of Islam