The past week saw Virgin America VA and SkyWest SKYW reporting strong first-quarter 2016 results, thanks to the dip in fuel costs. On the other hand, Allegiant Travel Company’s ALGT in-line earnings and revenue miss was quite a disappointment.On the non-earnings front, Delta Air Lines DAL and Alaska Air Group ALK reported healthy traffic data for the month of April. Load factor (% of seats filled by passengers) increased for both the carriers as traffic growth outpaced capacity expansion in the month.On the price front, the NYSE ARCA Airline index declined 2.6% to $88.43 over the past five trading days.Read the last Airline Stock Roundup for Apr 27, 2016.Recap of the Past Week’s Most Important Stories1. Low-cost carrier Virgin America's first-quarter earnings (excluding special items) of 41 cents per share beat the Zacks Consensus Estimate of 36 cents. Results were aided by low fuel costs. Operating revenues came in at $364 million, surpassing the Zacks Consensus Estimate of $362 million. Revenues also improved 11.5% from the year-ago figure.Meanwhile, capacity increased 15.8% on a 15.9% rise in traffic during the quarter. Load factor was flat on a year-over-year basis at 80.1%. Passenger revenue per available seat mile (PRASM: a measure of unit revenue) declined 3.8% to 9.88 cents in the reported quarter. Total RASM decreased 3.7% in the first quarter of 2016 and yield per passenger mile declined 3.7%. 2. St. George, Utah-based SkyWest, Inc.’s first-quarter earnings of 52 cents per share was way ahead of the Zacks Consensus Estimate of 25 cents. Earnings also improved approximately 68% from the year-ago figure. Quarterly revenues of $762 million comfortably beat the Zacks Consensus Estimate of $738 million and expanded marginally on a year-over-year basis. SkyWest’s efforts to modernize its fleet by adding new aircraft and removing unprofitable/less profitable ones drove the upbeat results.3. Alaska Air Group, the parent company of Alaska Airlines and Horizon Air, posted a significant rise in air traffic for Apr 2016. Revenue passenger miles (RPMs) – a measure of air traffic – improved 11.1% on a 10.4% capacity expansion. Load factor increased to 84.1% from 83.6% in Apr 2015 as capacity expansion was outpaced by the increase in traffic.4. Delta Air Lines revealed a 2.7% increase in RPMs for April while capacity improved 2.5%. Load factor increased to 83.3% from 83.2% in Apr 2015 as capacity expansion lagged the increase in traffic. However, Delta witnessed a 4% drop in PRASM in the month, mainly due to foreign exchange woes.On a separate note, good news flowed in for Delta after the Mexican Federal Economic Competition Commission approved (with conditions) the carrier’s proposed $1.5 billion joint venture with Grupo Aeromexico. The carriers aim to strengthen their partnership with this JV.5. Allegiant Travel Company’s first-quarter 2016 earnings per share of $4.29 were line with the Zacks Consensus Estimate. Quarterly revenues increased 5.9% year over year to $348.6 million, narrowly missing the Zacks Consensus Estimate. Air traffic rose 15% year over year on an 18.8% rise in capacity, while load factor stood at 84% compared with 86.8% recorded in the year-ago quarter. Fuel expense per ASM declined 35.1% in the reported quarter, thus aiding the bottom line. Fuel price (average) declined 33.2% to $1.29 per gallon in the reported quarter.For the second quarter of 2016, the company expects cost per available seat mile (CASM), excluding fuel, to grow in the range of 4% to 6%. TRASM in the second quarter is likely to decline in the band of 10% to 8%.Performance The following table shows the price movement of the major airline players over the past week and during the last 6 months. CompanyPast WeekLast 6 monthsHA-3.32%17.85%UAL-3.90%-21.83%GOL-0.28%-21.78%DAL-1.63%-15.28%JBLU-2.35%-20.38%AAL-6.28%-24.22%SAVE-9.16%24.53%LUV-6.22%-7.50%VA0.50%49.41%ALK-5.34%-9.04% The table shows that almost all airline stocks traded in the red over the past week with shares of low-cost carrier Spirit Airlines depreciating the most (9.16%). Virgin America was the sole gainer over the period on the back of its impressive first-quarter results.Over the past six months as well, most airline stocks traded in the red leading to the NYSE ARCA Airline index declining 4.49%%. Shares of Virgin America appreciated the most (49.41%) during the period while American Airlines AAL emerged as the biggest laggard (24.22%).What's Next in the Airline Space?Latin American carrier Copa Holdings CPA is slated to release its first-quarter 2016 results on May 5. Moreover, multiple traffic updates for the month of April are expected over the next few days. 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 >>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 DELTA AIR LINES (DAL): Free Stock Analysis Report COPA HLDGS SA-A (CPA): Free Stock Analysis Report SKYWEST INC (SKYW): Free Stock Analysis Report ALLEGIANT TRAVL (ALGT): Free Stock Analysis Report ALASKA AIR GRP (ALK): Free Stock Analysis Report AMER AIRLINES (AAL): Free Stock Analysis Report VIRGIN AMERICA (VA): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research