Reference: http://www.alfawzan.af.org.sa/node/15990
Question: During Ramadhaan, if I travelled for ‘umrah by airplane, should I fast or not?
Response: [Both] this is permissible for you [to do], and that is permissible for you [to do] – that you do not fast. Bearing in mind that you are travelling, so not fasting is better for the traveller, while it is permissible for you to fast [if you choose to do so].