It's no secret that not all airplane food is created equal. Sure, some airlines are churning out some delicious offerings, like the world's oldest bread on Turkish Airlines or Michelin-starred chef Brandon Jew's meals on select Alaska Airlines first class routes. But usually, meals in the friendly skies just aren't that great, which is why it's always a good idea to bring your own snacks on board.

But before you pack your carry-on, know that when it comes to airline etiquette, there are a handful of items that are better left at the gate. Flight attendants past and present share what food and drinks you should never bring on an airplane (at least, if you don't want to aggravate all your fellow passengers and the crew!).

Hard-Boiled Eggs

Don't be *that* guy. You know the one. That person who brings a Ziploc baggie filled with hard-boiled eggs. "I worked a long haul international and a couple pulled out a bag of like 10 or 12 and started peeling away," shared one flight attendant on a Reddit thread. "It smelled awful the whole flight and they were just a couple rows away from my jumpseat."

There's also the food-safety factor. After they're cooked, you still need to keep eggs at a safe temperature to avoid the growth of bacteria. Unless you're going the length to pack yours with an ice pack (and providing nose plugs for your neighbors) you probably don't want to risk it.

Or Any Other Other Strong-Smelling Foods

Many flight attendants were in agreement about the smelly food situation. Tuna salad is unfortunately a quite common culprit, with one person claiming that bringing it aboard should be an FAA violation. Curry, raw onions, fried food, jerky, kimchi, fish sauce, and fish and chips were also mentioned as no-no's on the airplane.

"Honestly anything that smells, either good or bad" is a no-go, summarized one flight attendant. He then give some good food for thought: "Flying is probably the one and only time I would recommend bland food, if only to help your guts under pressure."

Anything With Shells

Sure, they might be tasty and have a good amount of protein to tide you over for the duration of your flight, but seeds and nuts with shells can be a pain in the you-know-what to clean up. One flight attendant shared their pet peeve: when people bring pistachio and/or sunflower seeds in the shell, only to leave them in seatback pocket." I curse them under my breath as I dig 43,000 tiny pieces out," they say.

That goes for bananas, too. (Shells, peels, same difference!) "I am so sick of finding banana peels in the seat back pockets," one flight attendant shared. As a common courtesy, if you bring it on the plane, you best bring it off. Don't leave a mess for your flight attendants to clean up.

Cheerios & Goldfish

"I also get annoyed with parents that bring snacks for their young children that can potentially make a mess… I know that's very petty of me," one flight attendant shares, calling out snacks like Cheerios and Goldfish. "Anything that could be stepped on and make a huge mess, because majority of parents will not clean it up and it gets in the carpet."

Pizza Boxes

Another common no-no? Bringing aboard pizza in a big pizza box. According to one FA, planes have "limited trash and stowage space," adding, "those boxes take up like a quarter of our garbage can." Many flight attendants agree, complaining about customers who bring them on the plane. One flight attendant claimed there was no room for them to toss a box once, so they made the passenger sit with it on their lap for the duration of the flight.

Alcohol

This one should be a no-brainer considering you're not allowed to bring alcohol on a plane and drink it, but according to many flight attendants, it happens all the time.

"Occasionally passengers will try to sneak their purchased alcohol from inside the airport onto the plane and they aren’t allowed to do that, so that will drive us crazy," our anonymous source says.