Praying on board an airplane when one is in a state of janaabah (impurity)
Question

                It may so happen during a long journey that some travellers fall asleep in their seats and may experience wet dreams, or a traveller may board the plane having forgotten that he is in a state of janaabah, or a woman may become pure from her period or post-natal bleeding when the time for Fajr prayer begins. The plane will not reach the other country until after that time is over, and the safety regulations on board the plane absolutely forbid taking a bath in the washroom because the facilities are not suited for that. What should one do?
Praise be to Allah.If it is possible to do tayammum 
          using the furnishings of the airplane, then you should do so. If that 
          is not possible because they are free from dust, then you should pray 
          even if you are not taahir, then as soon as you are able to purify yourself 
          after that, then do so.