Repeating the salaah performed on an aeroplane while seated
Q: I read in one of your fatwas that if a person is unable to pray standing in a plane and therefore prays seated, they must repeat the salah later on. Is this because
* The first salah was invalid - so that they should intend qada when they repeat it?
* Or was the first salah valid (i.e. fulfilled the fard) and the second one just a repetition of it in a more perfect manner?