Originally Posted by
vasantn
My daughter is moving to Heidelberg, Germany (nearest airport FRA) and she will be coming back to New York to visit 3-4 times a year. She does not enjoy flying so she prefers nonstops. Star Alliance seems to be her best bet where she has the choice of UA, LH, and TP. Which airline's FF program would it make the most sense for her to join?
UA and LH are the only non-stop options on Star Alliance right now. Soon enough, SQ will be back to flying JFK-FRA, too. Besides that, you also got DL.
Assuming your daughter is looking for value flights (booking out at least 6-8 weeks in advance), FF status is not really gonna happen unless she has other air travel going on. I'd mostly look for a program where the redeemable miles don't expire. The US-based programs UA and DL seem to be the main options.
I don't know why you mention TP. They don't fly NYC-FRA. And they are in financial difficulties. Unless for some rare special cases (TP status match), I wouldn't look more closely at them.