She said the man was travelling alone and crew put a blanket over him.
She wrote: "No one knew except for the doctor that had been helping us on board. We had moved everyone sitting next to him in order for the doctor to help him so the doctor just sat next to the guy for the rest of the flight.
"The guests knew someone on board was sick [cause we made an announcement asking for a doctor] but they didn't know the guy getting taken off the flight was dead. It was a crazy day."
Windscreen shattered 'into a thousand pieces'
Reddit user TRex_N_Truex, who claimed to be a pilot, said his flight crew received a scare when one of the cockpit's windscreens shattered "into a thousand pieces".
They wrote: 'It sounded like someone fired a shotgun in the cockpit. We ended up diverting.
"Got on the ground safely and waited for a spare airplane to be sent so we can continue. Imagine watching this happen directly in front of your face and being told a few hours later to go back up and try again.
"This is why pilots are more than just button pushers."
Wake turbulence
User TGMcGonigle was co-piloting a McDonnell Douglas DC-9 to New York when the plane was caught up in the wake turbulence of a larger passenger jet, putting it in danger of a crash.
They wrote: "The captain was flying, and as we approached a point where a right turn was required the aircraft started to roll left instead.
"Puzzled, I looked over to see that he had the yoke [a control device] all the way to the right, but we continued to roll left.
"We were passing about 60 degrees of bank, and the nose was starting to drop. Just at that moment, he said something I've never heard from another pilot, before or since: "Help me".
"I applied the right rudder [for directional control], which stopped the roll. The aircraft just sort of hung there for a moment, then abruptly snapped back to the right.
"Everything returned to normal, and we resumed the arrival, each wondering what the hell had just happened."
They were then informed by air traffic control to "use caution for wake turbulence", which had affected three earlier arrivals.
The user added: "What strikes you at a moment like that is, 'fix this'. Your training kicks in and you do what you need to do."
Plane runs a 'gauntlet'
Air traffic controllers joined the discussion and shared their scariest or most stressful experiences while guiding pilots.
User AnImbroglio once had a pilot go NORDO (the term used when a plane isn't on the proper radio frequency)
They wrote: "It happens fairly often, and there are a number of things we can do to get you back in the right place.
"This particular guy, however, went NORDO at precisely the worst time."
The plane was flying east when it lost its radio and turned south, but wasn't at the correct altitude.
The Reddit user wrote: "There were about a dozen different planes going northbound that were at his altitude, so he ended up running one heck of a gauntlet through all these people as I descending and climbing them to get them out of his way."
He said the pilot chose an altitude on his own and ended up in the path of the planes he had just moved.
The user added: "When you have closure rates of over 1,000 knots, that's not a lot of time to react to those things."
'Moments away from imminent death'
Passengers, including a man who had a harrowing experience on a flight in Canada, weighed in with terrifying tales that everyone on board was aware of.
The user said the plane was flying into Fort McMurray, Alberta, from Calgary when it suddenly lifted and gained altitude seconds before it should have touched down on the runway.
The Reddit user wrote: "As the plane turns around I looked out the window to see a plane just taking off from the runway.
"The pilot then comes on the overhead speaker and said 'Sorry about that folks, as we were coming in to land a plane turned onto the runway, we will turn around and land in about 15 minutes.'"
"I thought to myself, 'Wow, I was moments away from imminent death.' On the way out I thanked the pilot for his reflexes."
'Insane' snowstorm
Flying through a storm can be a nerve-wracking experience for crew and passengers, and it certainly was on a flight from Chicago to Buffalo.
Reddit user icantthinkofaname0 said the plane flew through an 'insane' snowstorm with severe turbulence.
They wrote: 'We spent an hour on the Chicago tarmac getting de-icing fluid on the wings.
Once we were in the air there was insane turbulence.
"We approached Buffalo and it felt like we were on a roller coaster as the plane went up and down as we circled the runway."
The plane ended up diverting and landing in Albany instead.