Rav Scheinberg was asked what one should do if he is davening SE on a plane in such a way that he is blocking something that the flight attendant needs access to, and the Rav recommended that one should point to the siddur that he is holding in his hand and she will chop that he is davening and will wait for him to finish.
I really dont belive a Rav would say this. A person has no idea why the flight attendent needs to see a passenger. It could be a silly thing like the person needs a pillow or a blanket or it could be the passenger is feeling ill (Getting ill on a plane is quite common) and the flight attendent will not know until they get to the passenger who needs them