It felt like just another flight for South African pilot Rudolph Erasmus, until he noticed an extra passenger on his plane at 11,000ft in the air.
However, it wasn't a human, but a cobra slithering under his seat.
"To be truly honest, it's as if my brain did not register what was going on," he told the BBC.
"It was a moment of [...] awe," he added, saying he initially thought the cold feeling on his back was his water bottle.
"I felt this cool sensation, sort of, crawling up my shirt," he said, thinking he may not have closed the bottle properly and water might have been dripping down his shirt.
"As I turned to the left and looked down I saw the cobra [...] receding its head backwards underneath the seat."
He then made an emergency landing on his flight from Bloemfontein to Pretoria. The plane was carrying four others, as well as the snake.
A bite from a Cape cobra is lethal and can kill someone in just 30 minutes, so not wanting to cause panic, Mr Erasmus says he thought carefully before calmly telling those on board that there was an extra unwanted passenger.
He was also "so scared the snake might have gone to the back and cause mass panic".
In the end, he decided the tell them. "I did inform the passengers: 'Listen the snake is inside the aircraft, it's underneath my seat, so let's try and get down to the ground as soon as we can.'"
So how did the passengers react? Mr Erasmus described a moment of absolute silence: "You could hear a needle drop and I think everyone froze for a moment or two."
Pilots are trained for lots of scenarios, but certainly not for dealing with snakes in the cockpit he said, telling the BBC that panicking would have just made the situation worse.
The plane made an emergency landing in the city of Welkom.
However, the presence of the snake, although shocking, was not a total surprise. Two people working at Worcester flying club where the plane first took off, said they had earlier spotted a reptile taking refuge under the aircraft. They tried to "grab" it, but without success.
Mr Erasmus said he tried to find the snake before boarding the aircraft with his passengers, but "unfortunately it was not there, so we all then safely assumed that it must have crawled out overnight or earlier that morning, which was on Monday".
The slithering passenger is still missing, as engineers who then stripped the plane are yet to find it.
Mr Erasmus has been hailed a hero, with South African civil aviation commissioner, Poppy Khosa, praising his "great airmanship indeed which saved all lives on board," according to the News24 site.
But the modest pilot says he doesn't feel like he's special for what he did: "I think that's a bit blown up if I can be direct," he said. "It's also my passengers that remained calm as well.