The European airline sector is benefiting from the recent drop in crude oil prices, according to Barclays Capital, providing an extra reason to remain bullish on the sector.The British broker signals that even with an overly cautious hypothesis over the relationship between oil prices and revenue, the estimates and price targets for these companies will rise.The investment firm decided to raise its price target for Air France-KLM by 3% to 16 euros and for IAG by 8% to 400p while maintaining overweight recommendations for both companies.These analysts also raised their price target by 12% for Lufthansa to 19 euros and 13% for Ryanair to 4.25 euros. They reiterated their neutral recommendations for both companies. For EasyJet, they raised the price target by 14% to 375p and confirmed their underweight recommendation.Barclays Capital remains positive on this sector.At 12:11pm, IAG is up 0.97% to 2.80 euros, Air France-KLM is up 1.25% to 10.54 euros, Lufthansa is up 1.68% to 15.15 euros, Ryanair is up 0.87% to 360 pence, and EasyJet is up 2.61% to 362 pence.M.D.