Delta Air Lines Inc. DAL kick-started the second-quarter earnings season in the airline space on a disappointing note. The company’s earnings as well as revenues lagged expectations. Also, the top- and bottom-line miss disappointed investors. Consequently, shares of the company were down in early trading.The Atlanta, GA-based carrier’s second-quarter earnings (excluding special items) of $1.64 per share missed the Zacks Consensus Estimate of $1.66.However, earnings climbed 11.56% on a year-over-year basis on the back of a 3.3% operating revenue growth. Meanwhile, quarterly operating revenues of $10.79 billion fell short of the Zacks Consensus Estimate.During the quarter, passenger revenues, cargo revenues and others increased 2.9%, 10.9% and 4.9%, respectively, on a year-over-year basis. Average fuel price (adjusted) was down 15.7% to $1.66 per gallon.Operating StatisticsRevenue passenger miles (a measure of air traffic) increased 2.1% to approximately 57.6 billion. Capacity or available seat miles expanded 0.4% to 66.2 billion. Load factor (percentage of seats filled by passengers) improved 140 basis points year over year to 86.9% as traffic growth outpaced capacity expansion in the quarter, leading to packed planes.Passenger revenue per available seat mile (PRASM) climbed 2.5% year over year. In fact, this was the first quarter in which the carrier recorded quarterly unit revenue growth since the fourth quarter of 2014. In addition, passenger mile yield grew 0.8%.Operating ExpensesTotal operating expenses, including special items, increased 9% year over year to $8,763 million. Non-fuel consolidated unit cost or cost per available seat mile (CASM:normalized), including profit sharing, climbed 5.5%, mainly owing to wage increases, product investments and the operational disruption in April.LiquidityAt the end of the second quarter, Delta had $2.24 billion in cash and cash equivalents and adjusted net debt of $8.4 billion. The carrier generated $2.8 billion of adjusted operating cash flow and $1.9 billion in free cash flow in the quarter.Dividend and Share RepurchaseDelta returned $748 million to its shareholders through dividends ($148 million) and share buybacks ($600 million) in the quarter under review. In fact, we are impressed with the company’s efforts to return greater value to its investors.In May 2017, the company’s board of directors approved a new share repurchase program worth $5 billion. The new share buyback plan is expected to be completed by Jun 2020. Simultaneously, the airline major increased its quarterly dividend by over 50%.Delta Air Lines, Inc. Price, Consensus and EPS Surprise Delta Air Lines, Inc. Price, Consensus and EPS Surprise | Delta Air Lines, Inc. QuoteThird-Quarter GuidanceThe carrier expects operating margin in the range of 18% to 20%. The estimated fuel price, including taxes and refinery impact, is anticipated in the band of $1.55 to $1.60 per gallon for the third quarter. System capacity is projected to be up approximately 2% on a year-over-year basis.Moreover, the company expects passenger unit revenue to increase in the band of 2.5% to 4.5% (on a year-over-year basis) in the third quarter. Non-fuel unit cost (including profit sharing) is anticipated to increase approximately 4% in the quarter.Upcoming Airline ReleasesChicago-based United Continental Holdings UAL is scheduled to release its second quarter results on Jul 18. JetBlue Airways JBLU, based in Long Island City, NY, is slated to release its second quarter results on Jul 25.Zacks Rank & Key PickDelta sports a Zacks Rank #1 (Strong Buy). Investors interested in the airline space may also consider Ryanair Holdings RYAAY that carries the same bullish rank as Delta. You can see the complete list of today’s Zacks #1 Rank stocks here. We note that shares of Ryanair Holdings have gained 34.6% on a year-to-date basis.More Stock News: This Is Bigger than the iPhone!It could become the mother of all technological revolutions. Apple sold a mere 1 billion iPhones in 10 years but a new breakthrough is expected to generate more than 27 billion devices in just 3 years, creating a $1.7 trillion market.Zacks has just released a Special Report that spotlights this fast-emerging phenomenon and 6 tickers for taking advantage of it. If you don't buy now, you may kick yourself in 2020. Click here for the 6 trades >> Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Ryanair Holdings PLC (RYAAY): Free Stock Analysis Report JetBlue Airways Corporation (JBLU): Free Stock Analysis Report Delta Air Lines, Inc. (DAL): Free Stock Analysis Report United Continental Holdings, Inc. (UAL): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research