Can You Pray in Places Higher than the Ka`bah?
Question

What is the rule on praying in places that are higher than the Ka`bah?
Praise be to Allah.There is nothing wrong with praying in places and buildings that are higher than the Ka`bah, such as praying on the roof of Al-Masjid Al-Haram, or on Jabal Abu Qubays, or on the upper floors of the high-rises surrounding Al-Masjid Al-Haram. The jurists refer to this matter as praying in the direction of the Ka`bah.
An-Nawawi (may Allah have mercy on him) said:
Our companion said: If someone stands on [Jabal] Abu Qubays or any of the other places that are above the level of the Ka`bah and close to it, his prayer is valid and there is no difference of opinion concerning that, because he is regarded as facing towards the qiblah.” (End quote from Al-Majmu`,  3/198)
Al-Bahuti (may Allah have mercy on him) said:
If he prays on a mountain that is higher than the level of the Ka`bah, such as Abu Qubays, the prayer offered facing in its direction is valid. The same applies if he digs a hole in the ground, so that he is below the level of the Ka`bah. The prayer offered facing in its direction is valid, because of what we have noted above, which is that what matters is the direction, not the walls.” (End quote from Kashshaf Al-Qina‘`, 1/300)
Based on that, there is nothing wrong with praying in places that are higher than the Ka`bah, or in an aeroplane, if the worshipper is  facing the direction of the Ka`bah .
You should understand that the one who is close to the Ka`bah must face it precisely, and the one who is far away from it must face in its direction, as we have explained in the answer to question no. 42574 .
For more details, please see the following answers:
Places Where Prayer Is Not Allowed
Are You Allowed to Pray in the Bathroom?
Is Praying at Graves Permissible?
Is Praying in a Room with a Toilet Permissible?
And Allah knows best.