There is a very regrettable thing with regard to this matter which is the carelessness of some women concerning travelling by airplane without a Mahram.
They are very negligent in this matter: One finds women travelling by airplane alone, and their justification for doing this is that they say that her Mahram escorted her in the airport from which the airplane took off and the other Mahram will meet her in the airport at which the airplane lands, and that in the airplane she is safe.
This justification is weak in reality, because the Mahram who accompanies her does not admit her onto the airplane, he only admits her to the departure lounge.
It may also be that the airplane is delayed in taking off and so this woman remains lost, or the airplane might take off and then be unable to land at the intended airport due to some reason or another, and so it lands at some other place, else and so this woman will be lost. Or, the airplane might land at the intended airport, but the Mahram who is supposed to meet her does not arrive due to one reason or another, such as illness, sleep or a car accident which prevents him from getting there, or something else.
Even if all of these things did not happen, and the airplane landed at the correct time of arrival and the Mahram who was supposed to meet her was present, there might be some man sitting next to her on the airplane who does not fear Allah, the Most High and does not respect the worshippers of Allah, and he might be attracted to her and she to him, which might lead to Fitnah (temptation, trial) and unlawful deeds, as is well known.
So, it is incumbent upon a woman to fear Allah, the Almighty, the All-Powerful and not to travel except with a Mahram. It is also incumbent upon women’s male guardians whom Allah has made protectors and maintainers of women to fear Allah, the Almighty, the Ail-Powerful, and to avoid being negligent to those they are Mahrim for, and losing their zeal and their religion, for a person is responsible for his family. Because Allah, the Most High has made them a trust for him; He, the Most High says:
“O you believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allah, but do that which they are commanded.”
Fatawa Arkanul-Islam – Fatawa on Hajj (Pilgrimage) Q.No 458
Islamic Verdicts on t he Pillars of Islam (Volume Two) – Prayer, Zakah, Fasting, Hajj
By the Honorable haikh Muhammad bin Salih Al- ‘Uthaimeen
Collected and Arranged by : Fahd bin Nasir bin Ibrahim As-Sulaiman , Dar-us-salam Publications