Ruling on a woman traveling by airplane without a mahram

Question: From 'Abd al-'Aziz ibn 'Abd Allah ibn Baz to the honorable brother, Professor A. S. 'A., may Allah grant him success in all good, amen.
Peace be upon you, and Allah's mercy and blessings. And after that:
Your letter dated 15/1/1394 AH has reached you, may Allah guide you, and what it contained regarding the fact that you disagreed with one of your colleagues on the permissibility of a Muslim woman traveling by airplane without a mahram, even though her wali is with her until she boards the plane, and her other mahram is there to receive her in the country she is heading to, and your desire for a fatwa was known.

Answer: It is not permissible for a Muslim woman to travel by airplane or any other means without a mahram accompanying her in her journey; due to the generality of the saying of the Prophet (peace and blessings be upon him): which is agreed upon as authentic; and because it is possible that she may be exposed to what is forbidden during the flight by any means, as long as she does not have someone to protect her. Another matter is that airplanes sometimes experience disasters, so they land at an airport other than the one intended, and their passengers stay in a hotel or elsewhere while waiting for repairs, or for another plane to be secured, and they may remain waiting for a long time, a day, or more, and in this there is exposure for the woman traveling alone to what is forbidden.
In summary, the secrets of the rulings of Islamic Shari'ah are many and great, and some of them may be hidden from us, so it is obligatory to adhere to the Shari'ah evidence and to be cautious of contradicting it without a Shari'ah justification that is free from doubt. May Allah grant all success in understanding the religion and steadfastness upon it. He is the best of those asked, and peace be upon you, and Allah's mercy and blessings.