This is why JetBlue just had a really good quarter by Reuters @FortuneMagazine October 27, 2015, 12:29 PM EST E-mail Tweet Facebook Linkedin Share icons Shares of JetBlue JBLU are losing altitude Tuesday, even though the airline said its third-quarter profit more than doubled from a year earlier. The U.S. budget carrier’s profit inched above analysts’ estimates as cheap fuel and revenue from new checked bag fees and first-class seats added to its bottom line. JetBlue launched new fare tiers in late June, including its first charge for a checked bag—a major change for the carrier. Now that change is paying off, with the airline reporting $40 million in revenue from the new fare, according to USA Today. Similar to other airlines, JetBlue is benefitting from lower oil prices. The airline said it hedged around 14% of its fuel consumption in the third quarter, resulting in a realized fuel price of $1.85 per gallon, down 39% from the third quarter 2014 realized fuel price of $3.05. The U.S. budget carrier earned $198 million in the third quarter, up from $79 million a year ago. It earned 58 cents per diluted share, compared with the average analyst estimate of 57 cents, according to Thomson Reuters I/B/E/S.