The DGCA in its guidelines mentions that airlines must ensure that 50 percent of their cockpit and cabin crew members are subjected to preflight alcohol tests on a daily basis.

According to the advisory issued by DGCA, there are chances of a decrease in performance even 12 hours after a bout of drink, when blood alcohol level remains zero.

"Alcohol present in the body even in small quantities jeopardizes flight safety on several counts and is likely to adversely affect an aviator well into the hangover period," the advisory stated.