Hi! I may be a newbie here but I'd been flying like a qtr of a century and been praying and fasting for longer than that. (Yep, I'm a Muslim.)
Thanks to computers, mobile phones, wi-fi, 3G, internet, etc. it has become easier to plan and observe worshipping while travelling.
But let me start by answering the thread question first: No. No prayer calls or anything that reminds you of Islam while on board a THY plane (except for the little pig picture with a cross on it that comes with the tray, which doesn't put THY ahead of Lufthansa at all!)
Personally, I've found THY to be much behind western airlines when it comes to assistance for prayers. When asked which direction is the Qiblah (direction towards Mecca), the FA says "The Qiblah is in our hearts" (meaning 'Stay in your seat and pray towards whichever direction we're flying!) Compare this to the treatment of BA which draws the place where you'll put your prayer rug. ^
Here's what I do before and during the travel:
I prepare an Excel sheet showing the prayer times and Qiblah directions of the airports I'll fly through, covering the whole travel period. I'd rather pray at the airport than on board. But if there's a long flight that includes one or more prayer intervals completely, I have to do a bit more calculation. I use Google Earth to draw the flight routes on the globe (then rotate the globe to look down on the route orthogonally so it looks like a straight line) and I find the angles of Qiblah at various points on the route. If possible, I try ask the pilot/flight engineer/whoever I can find before the flight, what they expect the maximum angle of deviation between air and ground speed would be in that flight (To be used as a correction factor for the direction of Qiblah). Yet, this is generally +/- depending on the wind direction and impossible to know exactly beforehand. There's a tolerance margin for Qiblah defined by religious scholars, which makes life easier for Muslims. (Views differ on that being between +/- 15 degrees to +/- 90 degrees.) The 'must' part is that a Muslim has to do his/her best to try to find the direction of Qiblah before praying. If it's impossible to decide, s/he takes his/her best guess. (The prayer is void if s/he starts the prayer without caring about the direction at all (EVEN IF s/he hits the spot perectly!)).
A Muslim has to correct his/her direction while praying if the carrier boarded, a ship for example, turns. Yet, this is not possible to judge on the plane. I don't now; the Saudi Princes may think of installing gyroscopic prayer modules into their planes, that would be set towards Mecca and stay like that throughout the flight. (I know such stuff existed for bombardiers.) The Saudi on the space shuttle must have had a hard time!
Judging the prayer time is more tricky. I use a geochrone, my watch and the view from the window. Depending on whether your flying Eastward or Westward, the prayer intervals may get shorter or longer, respectively. (The fasting times likewise.) Although the night prayer generally has the longest interval (from the start of darkness till the first light beam of dawn), sometimes it does not exist at all! Flying over the North Atlantic on a summer night on a route close to Iceland leaves you with no darkness at all. Then I look at the geochrone and try to find the point and time when there'll be a nearest place that experiences the 'night' somewhere in the South and hit the intersection of its meridian and the plane's route.
As for praying while seated, my denomination of Islam does not allow that. I have to put my prayer rug on the floor and pray on it. While the kitchen part is quite spacious on large jets (We'd even prayed in congragation with a Saudi guy once, on the way back from JFK), in smaller planes I have to utilize the little area in front of the toilet doors. If I have company, I ask the person to occupy the toilet for the duration of my prayer so that the door is not used in the meantime. Most of the prayers are shortened while travelling. Yet it takes a few minutes, and it's quite hard when there's people entering/leaving the toilets. And if the 'Fasten seatbelt' lights are turned on while praying, the FA interferes.
For fasting, I abide with the rule of thumb depending on the sun. Thus it's really short while flying Eastward, but I may even starve if I fly Westward long enough (with the sun travelling with me as well and never setting!) Of course, fasting is not compulsory if travelling over 90 km, and it's recommended to use this license to do it properly. I make up for those lost days after the month of Ramadan.
As for the food served on board, it's a big joke! Lufthansa's Moslem food is not halal (as they admit on their website: http://www.lufthansa.com/us/en/Special-meals and http://www.lufthansa.com/online/port...d=1874684&l=en ) Even THY suffices by saying there's no pork in the meal (as if it were sufficient to make it halal!) Of course, many Muslims are not aware of the complete rules of halal and they'd consume a lot of non-halal on their everyday lives without knowing. So, it's not a big surprise if they fail on board. I sometimes take my own sandwich with me, if the airline doesn't offer halal. Kosher doesn't solve the problem either (although it's much more strictly controlled at each stage from farm to fork), because you may end up with chicken dipped in kosher wine, which is no good for a Muslim.
I'm trying to get my friends in the IT sector to make a mashup of the websites like travelocity, mapmaker, namazvakti (=prayer time), google earth, etc. so that Muslims can input their travel plans and receive the complete schedule of their prayers during that journey. Of course, inconvenience can be discouraging! An Arab friend of mine had told me how the Hajis (pilgrims) had become suddenly restless when one of them announced that the prayer time had come, while they were flying back home from Mecca (Jeddah or Medinah, to be exact) right after completing the holy pilgrimage...
It has taken me (once nationwide top student & puzzle champion) some time to figure out these solutions and it'd be too much to expect from the average man on the street. We really need a website (or an app) for planning, and the assistance of the airline crews for observance; otherwise discrepancy and errors are inevitable.