Is it permissible to perform tayammum and pray sitting down, not facing the qiblah, in an airplane due to the inability to perform wudu’? Should the prayer be delayed until arriving at the hotel and be performed as qadaa’ (make-up prayer)? Is it permissible to combine and shorten prayers in the country of treatment?

Tayammum is only permissible for one who is genuinely or constructively unable to use water. A traveler on an airplane can perform ablution because water is available in the lavatory, and slight hardship does not permit tayammum. Facing the Qibla and standing in obligatory prayers are conditions and pillars that are only waived in case of inability. In such a situation, it is permissible to pray sitting and by gesturing, even if not facing the Qibla. It is not permissible to delay the Fajr prayer until after its time has expired upon landing; rather, the prayer must be performed on the airplane. As for prayer in the country of treatment, whoever intends to reside for four days or more is considered a resident from the first day of their arrival, and it is not permissible for them to avail themselves of travel concessions such as shortening prayers or breaking fast in Ramadan.