Posting a $54m profit in its second quarter, Frontier Airlines has joined the ranks of America’s most profitable airlines. Frontier and America’s other ultra-low-cost carrier, Spirit, are both highly profitable and have big growth ambitions. As long as oil prices remain low, they should go far. Meanwhile, Norwegian is taking a stab at the low-cost longhaul game in the transatlantic market. Is this for real this time, or is Norwegian simply riding a tailwind of cheap fuel and a robust U.S. economy? Meanwhile, European carriers are bullish about their current quarter and the next one. And with the economy continuing to slide in Brazil, what does it mean for Azul’s longhaul ambitions.