All flight deck and cabin crew need to take a alcohol breathalyzer test when reporting for duty at Jet and other carriers. The test is for zero ppm alcohol. If you didn't detox long enough (UA for example requires no alcohol 12h before reporting for duty, the FAA 8h) the test will come up positive and you are grounded and your medical certificate revoked. Pilots usually know better to stop drinking any alcohol well enough in advance (every person detoxes differently)... 21 pilots testing positive in one year is pretty low if you consider the amount of crew working in india.