The FAA started drug testing prior to that, more as a part of the bogus "War on Drugs." It's far cheaper to address a perceived safety concern than the real safety issues in the aviation industry. They later added alcohol testing (what's ironic about this is they generally test pilots and FAs AFTER a flight, not before. Go figure). Individual airlines may do additional testing of employees. I don't have the stats handy, but it's seldom an ATC or a pilot gets a true positive for drugs (I can think of three positives at a 350-controller ATC center in 20 years). FAs more often test positive, but they also have less to lose financially.

The FAA's own flight examiner at my husband's facility tested himself after eating a poppy seed bagel and tested positive for opiates.

FAA tests are urine tests, not hair tests, and yes it takes 3-4 weeks for marijuana to leave one's system (longer for very heavy users). We consume a lot of hemp, and I know that can show up. The FAA budget's been slim for drug testing though so we may never find out what happens there.

I'm assuming the stand-up and lean-to comments may refer to collection techniques females use.