Delta Air Lines in the December quarter earned net income of $425 million,

up substantially from $19 million a year earlier. Full-year 2011 net income also soared, to $854 million versus $593 million in 2010. The carrier's passenger revenue jumped 8 percent in the quarter and 11 percent, to $30.3 billion, for the year. "With the December quarter's strong revenue performance, Delta produced a revenue premium to the industry and fully covered our fuel cost increase with higher revenues," according to president Ed Bastian.