--FILE--passeggeri attendere all'aeroporto area di servizio per China Eastern Airlines in Nanjingi, est Chinas provincia dello Jiangsu, 12 luglio 2014. Cina¯s stat
--FILE--Passengers wait at the airport service area for China Eastern Airlines in Nanjingi, east Chinas Jiangsu province, 12 July 2014. China¯s state-owned airlines have had a turbulent year and are warning of first-half earnings to match when they report later this month.With the bulk of their earnings in renminbi and fuel and aircraft costs denominated in US dollars, China¯s big three airlines benefited from the Chinese currency¯s steady appreciation against the greenback over the past decade.But over recent weeks, Air China, China Eastern and China Southern have all issued profit warnings, citing foreign exchange losses from the renminbi¯s unexpected weakening earlier this year. China Eastern, the country¯s biggest carrier, was the latest to brace shareholders for disappointing numbers.Last month it said it would book a first-half profit of less than Rmb50m ($8m) compared with a Rmb582m profit for the same period in 2013.Based in Shanghai, China Eastern has also borne the brunt of recent cancellations stemming from Chinese military exercises, which have caused widespread disruption to flight services across eastern and central China. As many as 26, 000 flights could be affected by the time the People¯s Liberation Army operations end in mid-August.