Travelling during Ramadhaan is permissible as per shariah. Going in the path of Allah during Ramadhaan is sunnah.
Know that you would become a musafir(traveller) when you undertake to do a journey of 77kms or more. You become a musafir when you leave the border of the town you stay. If your town is densely populated, then you become musafir(traveller) when you leave the famous border of your town. But if you live in a village and the village is not densely populated and it has got cultivation in its outskirt, then you become musafir(traveller) when you leave the buildings or houses of your village. In other words, when leaving for your journey, if you stop by the cultivation ground in the outskirt of your village, then your 4 rakaats farzs salaahs becomes obligatorily 2 rakaats because you are already a musafir(a traveller). Please refer to your local muftis as to from which boundary you become traveller (musafir).
Know that once you are musafir(a traveller), then you should obligatorily perform 2 Zohr, 2 Assr and 2 Esha. Fajr, Maghrib and witr remain unchanged. Refer to below:
عَنْ مُجَاهِدٍ عَنْ ابْنِ عَبَّاسٍ قَالَ فَرَضَ اللَّهُ الصَّلَاةَ عَلَى لِسَانِ نَبِيِّكُمْ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي الْحَضَرِ أَرْبَعًا وَفِي السَّفَرِ رَكْعَتَيْنِ وَفِي الْخَوْفِ رَكْعَةً
Hazrat Ibn Abaas r.a. said: ‘’Allah Ta`ala has prescribed the obligation of performing salaah for non traveller 4 rakaats, traveller 2 rakaats.. prescribed through the (mubarak) tongue or wordings of your prophet Swalallahou `Alaihi Wasallam.’’(Muslim)
Besides the legislation on salaah, the Qur-aan formulate the legislation of fasting(Ramadhaan) during travelling:
‘’O you who believe, the fasts have been enjoined upon you….However, should any one of you be sick or on a journey, then(he should fast) a number of other days(equal to the missed ones);…However that you fast is better for you, if you only knew.’’(2:183-184)
The Coranic ayah brings permission for a traveller not to start fast. But still encourage a traveller to do fast Ramadhaan as the virtues are not comparable. Still the Qur-aan does not give permission to a traveller to break his fasts during travelling.
And if a traveller choose not to fast from sehri time, then he has to replace his fasts after Ramadhaan.
=) Important to know that you need to complete a fast if you are at sehri time in your home town. So if you are leaving your city after sehri, then it is farz for you to fast that time. And also it is not permissible for you to break that fast during travelling. The Qur-aan mentions permission not to start fast during travelling but does not allow to break fast during travelling.(Shami) If broken during travelling, then no Kaffarah, only qaza wajib.
=) Remember that if someone who is a traveller comes back to fetch something in his hometown during Ramadhaan and now breaks his fast in his hometown, then Qaza and Kaffarah is applicable. Kaffarah is to fast 60 consecutive days.
=) If a traveller started his fast during travelling and now decides to break his fast, then only qaza wajib. (Radul Muhtar).
=) When returning from a journey, if a traveller was not fasting, then when he enters his hometown or the place he will stay 15 days or more, then he has to stay away from food and drinks until sunset. And still he would have to replace that fast. If he did not eat or drink anything from sehri time and arrived before Zawaal to his home town, then he has no option but to fast that day.
Remember that sehri time is the actual sehri time of your particular location at that time. So if you are on the plane, then you have to look outside the window as to when the dawn starts. The first horizontal light that appears on the horizon is the sehri time. You may find an approximate time by locating your plane to the country you are nearest to. Find that country`s sehri time from net. If your plane is at maximum altitude, then minus 20 minutes from that time. For Maghrib, add 20 minutes for iftaar. Your iftaar is when you are seeing actually on the plane that the sun has set or the time calculated as per nearest country to the ground as above.
Note that we have taken precaution by mentioning 20 minutes as plane velocity or speed may surprise us on time schedules. When in doubt, then be more safe with precautionary times.
Ask permission to read farz salaah standing on the plane. Calculate qiblah as per the trajectory of the plane that you see on the screen as to Makkah. And know that you may read nafil sitting on your chair, without qibla direction. But it is farz to stand in a farz salaah and important to calculate qiblah. If the air hostess stops you, then do your salaah sitting on your chair and redo when on the ground.
Since our travelling is easier and more comfortable, we stress that all travellers to keep their fasts during their journeys.