In the final days of 2016, a pair of alarming reports surfaced that could rattle any traveler. Two commercial airline pilots, 8,400 miles from one another, were removed from their scheduled flights on suspicion of intoxication.

On New Year's Eve, Calgary police arrested a pilot for budget Canadian carrier Sunwing Airlines who was about to fly 99 passengers to Cancun, Mexico. The crew reported he was "behaving oddly" and passed out in the cockpit. Police allege his alcohol level was three times the legal limit.

A few days earlier, a pilot for Indonesian carrier Citilink reportedly delivered slurred announcements while the plane, scheduled to travel from Surabaya to Jakarta was still on the ground. Footage later surfaced of him struggling to get through a security checkpoint. The airline fired the pilot and two of its executives resigned.

Incidents of drunken pilots are very rare, especially considering there were 35 million scheduled flights last year, but they occur often enough. Last August, two United Airlines pilots were arrested in Glasgow airport on suspicion of drinking before a flight to Newark. In August 2015, a co-pilot for Latvian airline Air Baltic was sentenced to six months in prison after admitting to have indulged in whisky and beer.

And, though even less common, fatalities have been linked to an inebriated pilot. Russian prosecutors cited a pilot's intoxication as a cause in the 2008 crash an Aeroflot subsidiary's Boeing 737 that killed 88 people (paywall).

In the US pilots are subject to a blood-alcohol limit of 0.04%, half the legal limit for drivers in many US states. That's the same limit as for other critical jobs, such as air traffic controllers, ambulance drivers, and some ship captains.

But pilots aren't required to take a breathalyzer test before boarding their assigned plane each time. Instead, pilots are tested randomly or if there is reasonable suspicion. Of 13,149 tests on pilots for alcohol intoxication on commercial pilots in 2015, most of them random, only 10 failed, according to the Federal Aviation Administration.

As alcohol affects the body long after it is consumed, the FAA also cautions hangover symptoms such as headache, stuffy nose, upset stomach and dizziness can also be impair a pilot. The FAA warns pilots: "Cold showers, drinking black coffee, or breathing 100% oxygen cannot speed up the elimination of alcohol from the body." The FAA also requires pilots to stop drinking at least eight hours before the flight, or "from bottle to throttle." The standard is also required in Canada and Europe.

Yet for all these protective measures, the main defense against a drunk pilot is the eyes and ears of crew as well as the passengers themselves.

Cabin crew are encouraged to report any suspected intoxication of a pilot or other crew member. Passengers can reach out to cabin or the airport's ground staff if they have any concerns. In the case of the Sunwings incident, Calgary police said it had "all the potential for disaster," but checks and balances provided by the watchful crew prevented it. The FAA also operates a whistleblower program.

"Random testing has a way of keeping people on their toes," said Paul Hudson, the Florida-based president of Flyersrights.org, an airline passengers' advocacy group. While he said it's a "problem" any time a pilot under the influence gets into an airplane, the crew usually spots the individual if he or she isn't caught by random testing.

Hudson said the organization has more pressing issues than drunk pilots, such as how to increase security in unprotected parts of the airport, such as baggage claim, where a man opened fire, killing five people in Fort Lauderdale on Jan. 6.

The Air Line Pilots Association, which represents more than 54,000 pilots for US and Canadian airlines, says current measures are effective. "Rigorous peer, management, and regulator evaluation constantly takes place while airline pilots are on duty and that has proven an effective safeguard to detect personal circumstances that could affect safety," the union said in a statement to Quartz.

Pilot intoxication can bring criminal charges in the US, where pilots that try or succeed in flying drunk can face up to 15 years in prison. But they can also get off lightly; for example, an American Airlines pilot received a year of probation in August after pleading no contest to charges that he was drunk in the cockpit on a flight scheduled to leave for Philadelphia.

European officials last year proposed more rigorous screenings of a pilot's substance use and overall health, after a pilot of a Germanwings Airbus A320 intentionally crashed the plane in the French Alps, killing all 150 on board in March 2015.

The FAA says it doesn't have any planned changes to the current system to catch intoxicated pilots. "We have very high standards," a spokeswoman for the agency told Quartz. "The numbers are extremely low and our nation's pilots take fitness to fly and professionalism very seriously." (Though, as when Quartz reported on some pilots breaking safety rules by taking digital photos in the cockpit, some of their responses were less than professional.)

Other countries have stricter standards. India requires breathalyzer tests for pilots before all their scheduled flights and abstention for 12 hours before the flight. (It also has a bigger problem with drunk pilots; more than 40 pilots tested positive for being intoxicated on the job in 2015, for example.) In the UK and Australia, a pilot or co-pilot with a blood-alcohol limit over 0.02% is considered unfit for duty.
Pilots can also turn to a four-decade old substance-abuse treatment program called the Human Intervention Motivation Study, which can also help the them regain their certificates to fly again. But, then, should passengers be happy that the industry is trying to tackle a problem for these pilots, who face long hours and intense pressure? Or should they be concerned that that there's enough of them to form a support and treatment group?

https://qz.com/877003/dont-worry-only-around-one-out-of-every-1300-pilots-is-trying-to-fly-drunk/