One question you should never ask a flight attendant after passenger sparked security scare during flight

There's one question you should never ask a flight attendant as one passenger gravely found out when they triggered a security scare on the plane.

If you've ever travelled at all in an airport, you'll know they're pretty serious when it comes to security, and even more so post-9/11.

For instance, even 'joking' about having a bomb or hijacking a plane will land you in some serious hot water with law enforcement.

Now, a Redditor has revealed there's another question that will raise a red flag with cabin crew.

Discussing the matter on the Delta Reddit page, the traveler claimed another passenger sparked a security concern when on their late night flight from Los Angeles to Fort Lauderdale.

Security is intense in most airports (Getty Images)

Sitting in seat 1B, the person pulled aside a flight attendant and said: "Hey totally random question, but on my last couple flights I noticed the [flight attendants] did not block access to the galley when the pilot used the lavatory. Is this a new procedure for you guys?"

The Redditor said they saw the exchange unfold from their seat, 2B, as the flight attendant did not answer the question but said: "Hmm, that's news to me."

However, the staff member then went to speak to the cabin manager and clearly had flagged the alarming conversation.

According to the Reddit user, the manager returned to discuss the matter with the passenger in seat 1B.

"I understand you were inquiring on access procedures for the flight deck?", the manager reportedly asked to which the passenger laughed off: "Oh yeah, I was just curious."

The flight attendant apparently became alarmed by the question (Getty Images)

The flight leader then proceeded to tell the passenger that it was not 'something I can discuss with you.'

The passenger, clearly unaware why, then reportedly said: "Oh excuse me, I didn't realize I wasn't able to ask questions."

"I can answer most questions, but I cannot answer questions related to the security of the aircraft," the staff member explained.

When the passenger pressed further why they couldn't speak about a security-related question, the cabin manager reportedly snapped: "Seriously? You know why. Don’t you remember 9/11? We cannot talk about that stuff. So thank you for letting us know what you observed on your prior flights."

Then when the plane was mid-air and the pilot had a bathroom break, the Redditor said cabin crew escorted the pilot and blocked the galley while one 'stared at 1B the entire time'.

The Redditor said the pilot was then escorted to the bathroom during the flight (Getty Images)

“Unbelievable this guy can’t understand why it might be suspicious for the passenger seated in one of the two closest possible seats to the flight deck door to ask about galley obstructions procedures,” the Redditor added in the post.

Dozens then joked in the comments that the passenger is 'definitely on a list now' though some pointed out his eagle-eyed observational skills.

"Actually, this dude is probably the one person who will realise when something is out of the ordinary on the flight and speak up or will survive in a crash as he pays attention…", read one comment.

"For real," chimed another. "Doesn't this guy seem like he would be the most curious about galley obstruction procedures because he is the most proximal to them? Wouldn't it be f***** up if someone came up from 28E and started talking about galley obstruction protocol?"