Northern Passenger
Out bound
Routes have been spelled out well by other posters generaly Amsterdam to Constanta and then Van and out over Iranian border and down to gulf near Abadan then down gulf to DXB and then circle !. I have done this route many times but have yet to fly over Iraq. Have not flown to Calcutta but have over flown on the way to HK so route is DXB Karachi then across central India I would think.
In bound
Same route back to DXB but have had many routes back from there to Europe. Southern route along gulf coast and out over Saudia Arabia , Syria , Lebanon and then up to Turkey and back on to outbond track. Other times same as out bound and once way up into Iran and Russian airspace ended up over Odessa. Also once down the Med and up over Italy. Once approaching UK either in as outbound or often over London and up to Man.
The comments on the view are correct, the mountains of Iran /Turkey are quite somthing, and if on northern route you may pass over Qushm Island which has a collapsed salt dome which you can clearly see. Would recommend L/H side view on return.
Have a good trip.