Prime Minister Narendra Modi last week flagged off the first flight, on the Shimla-Delhi leg, of the government’s new scheme to boost regional air connectivity. The Ude Desh ka Aam Naagrik, or Udan scheme, is intended to revive air travel between 43 regional airports and metropolitan hubs. The aim is laudable. In many cases, regional airports are decaying. The new plan intends to create demand for these routes by auctioning them to a new set of regional airlines. The routes are being made viable by subsidies to airlines of various sorts. Half the seats on each flight will be sold