Raising the hands when making du’aa’ is one of the means of having the du’aa’ answered in any place. The Prophet (peace and blessings of Allaah be upon him) said: “Your Lord is characterized by modesty and concealment, so if a slave of His raises his hands (in supplication), He does not return them to him empty.” 

And he (peace and blessings of Allaah be upon him) said: “Allaah is Good and does not accept anything but that which is good. Allaah has enjoined upon the believers that which He enjoined upon the Messengers.” Allaah says (interpretation of the meaning): 

“O you who believe (in the Oneness of Allaah — Islamic Monotheism)! Eat of the lawful things that We have provided you with, and be grateful to Allaah”

[al-Baqarah 2:172]

And He says (interpretation of the meaning): 

“O (you) Messengers! Eat of the Tayyibaat [all kinds of Halaal (lawful) foods which Allaah has made lawful (meat of slaughtered eatable animals, milk products, fats, vegetables, fruits)] and do righteous deeds”

[al-Mu’minoon 21:51]

Then he mentioned a man who travels a great deal and becomes disheveled and covered with dust, who raises his hands to the heavens (and says), ‘O Lord, O Lord,’ when his food is haraam, his drink is haraam, his clothes are haraam and he has been nourished with haraam, so how can he receive a response?

 (Narrated by Muslim in his Saheeh). 

So he described raising the hands as being one of the means of having du’aa’ answered, and he described consuming haraam and nourishing oneself with haraam as being among the reasons why prayers are not answered.

 So this indicates that raising the hands is one of the means of having du’aa’ answered, whether that is in a plane, train, car, spaceship or whatever. If a person makes du’aa’ and raises his hands, this is one of the means of having one’s du’aa’ answered. But in situations where the Prophet (peace and blessings of Allaah be upon him) did not raise his hands, we should not raise our hands either, such as in the khutbah of Jumu’ah, where he did not raise his hands except when praying for rain (istisqa’), when he did raise his hands.

 Similarly, between the two prostrations and before saying the salaam at the end of the Tashahhud, he (peace and blessings of Allaah be upon him) did not raise his hands, so we do not raise our hands at these times when the Prophet (peace and blessings of Allaah be upon him) did not raise his hands.

 Because his doing it is evidence and his not doing it is evidence. Similarly after the salaam of the five daily prayers, the Prophet (peace and blessings of Allaah be upon him) would recite the dhikrs prescribed in sharee’ah but he did not raise his hands, so we do not raise our hands either, following his example. But in the situations when he did raise his hands, the Sunnah is to raise our hands, following his example, and because that is one of the means of having our prayers answered. Similarly in situations where a Muslim calls upon his Lord, and it was not narrated whether the Prophet (peace and blessings of Allaah be upon him) raised his hands or not, then we should raise our hands then, because of the ahaadeeth that indicate that raising the hands is one of the means of having prayers answered, as mentioned above.