This story originally appeared on ThisIsInsider.com.
While they may be checking out your outfit to see whether you're worthy of an upgrade, or scoping out your luggage to see whether you're trying to smuggle on a too-big carry-on, first and foremost flight attendants are trained to keep passengers safe, and will make certain snap-judgments to ensure that safety.
A Quora thread that asks "What do flight attendants notice about passengers as they board the plane?" reveals exactly what they're looking for.
According to Janice Bridger, a flight attendant of 27 years, "Air travel is fraught with inherent danger [...] — one must be constantly alert and aware of one's situation. So when I greet people, you better believe that I'm always very aware of each passenger who steps through the door of the aircraft."
Keep scrolling to see what they're looking for.
They check to see whether you're inebriated
According to Sjaak Schulteis, who was a cabin attendant for Lufthansa for 30 years, drunk passengers can be refused entry aboard the aircraft.
"If a guest coming aboard is drunk or intoxicated by any drug, it can happen that he or she is not allowed to enter the plane. [...] The first impression is often the right one, and we do refuse passengers who might be a danger for the safety of that flight. So far I have refused four passengers and was luckily backed up by the purser and captain. All of these were drunken passengers."
Bridger agrees. "If someone appears to be intoxicated, we don't want them on the plane," she says. "The potential for future problems is too great."
Flight attendant Amar Rama says, "In the event we may need to evacuate the aircraft, the goal is to do so in 90 seconds, and I don't want to unnecessarily risk my life or the life of others because a drunk or high person is being uncooperative."
They check to see if you're buff
"If I see someone who is muscular, powerful, strong, physically fit, I memorize his/her face and make a mental note of where they are sitting," says Bridger.
"I consider this person a resource for me. In the event of an attack on the flight or on me, these are my 'go-to' people. If a situation looks like it could develop, I'll privately and discreetly ask one of these people if they would be willing to help us if necessary. Help might involve subduing or restraining an unruly passenger. We hope it never happens, but we will prepare just in case it does."
They check to see whether you might be an airline employee
While fellow flight attendants often out themselves by bringing chocolates, Bridger says that she tries to " learn if we have any passengers who are airline employees, particularly crew members who have been trained in the in-flight procedures."
She says "They've been trained in what to do in an emergency, whether medical, mechanical, etc. They know how to handle the situations as well as I, and are trained to become an instant 'team member,' fitting right in immediately if needed. They are an invaluable resource for me, and I like to know who they are and where they're sitting."
They check to see if you're sick
Myriam Mimi, a flight attendant at Condor since 1994, says, "I check if they are drunk, drugged, sick, angry or afraid. That is extremely important as if I have the possibility to avoid any kind of troubles over the Atlantic, then I address it on ground. I say hello, welcome on board… and listen to how they respond."
According to Bridger, "I've had passengers board who look pasty and pale, deathly ill. We removed them; nobody wants their flu germs!"
Rama agrees. "We are in an enclosed space, therefore if you're sick, it's not right to pass it on to others."
She adds that anyone would prefer serious medical issues to occur on the ground, rather than in the air. "I once saw a woman at the gate have a heart attack — I was so thankful it happened on the ground and not while we were in flight. Flight attendants are all trained in CPR, Automated External Defibrillators, basic first aid emergencies, but we cannot diagnose you nor have the expertise, experience or treatment as doctor."
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They check to see if you're scared or anxious
Bridger says flight attendants keep an eye out for anyone who might be afraid of flying, "and need a word of comfort and encouragement."
They check for disabilities
According to Bridger, "I watch for disabilities that may disqualify someone from sitting in the exit row. They need to be able to physically lift a heavy hatch (up to 60 lbs) or open a heavy door (several hundred pounds). "
Rama says that they check for special needs to see whether passengers might "require extra assistance during an emergency. This way, if anything were to happen, I want to make sure they are not left behind."
They check to see if you're trying to do anything illegal
"I've had people try to smuggle pets in their purses or handbags, bottles of booze in their briefcases (booze is allowed as long as it stays capped. You just can't drink your own liquor on the plane)," says Bridger. "So yes, I need to be vigilant and aware, all behind my 'greeting face' of smile and pleasant, comforting welcome!"
She adds "when you consider that I have approximately 3-4 seconds to make that passenger feel welcomed and comfortable, and then also assess them for all of the potential that they bring with them onto the plane... well, it can require a lot of focus."
This article originally appeared on Travelandleisure.com.