American Airlines cancelled its planned inaugural flight between Chicago and Beijing earlier this month, citing a disagreement with Chinese aviation authorities over take-off and landing times. American says it turned down Chinese authorities’ offer of daily landing and take-off slots of 2:20 a.m. and 4:20 a.m. from Beijing. The impasse delays efforts by American, the secondlargest US carrier by traffic, to make further inroads into the fastest-growing economy in the world. It also could complicate planned “open-skies” talks between the US and China as some US businesses voice concern that Chinese protectionism is growing.