- A Delta Air Lines flight was turned around on Friday because of a passenger's explosive diarrhea.
- While technical or health issues often cause flight diversions, they can also stem from unlikely events.
Whether it's disruptive passengers, weather issues, fuel shortages, or medical concerns, commercial flights can often divert or turn around for technical or health-related reasons.
But in recent years, some pilots have made the decision to land for seemingly unlikely circumstances. On Friday, a Delta Air Lines flight was forced to turn around due to a passenger's diarrhea, which left a trail of poop on the aisle that the pilot told flight control was a "bio-hazard."
Here are six unusual reasons that can cause flights to turn around.
1. Funny smells
Sometimes, smells can become unbearable enough for passengers and crew that a flight is forced to U-turn.
In October, an American Airlines Boeing 737 flying from Miami to Barbados returned to Miami International Airport because of a "chemical odor in the cabin caused by the contents of a customer's carry-on luggage," The Independent reported.
Some cabin crew and passengers were evacuated by emergency services because they fell sick from the fumes in the luggage, per the outlet. They were sent to hospital out of an "abundance of caution," an airline spokesperson said, according to The Independent.
Even the smell of cannabis was enough to divert a British Airways flight traveling from London to Crete in 2016, per The Evening Standard. The flight's 174 passengers were diverted over Paris and sent back to London to wait for a replacement flight, the outlet reported.
However, an airline spokesperson told the outlet that no cannabis was found on board.
2. Clogged toilets
In April, 300 people on board an Austrian Airlines Boeing 777 had to turn back two hours into their journey from Vienna to New York because five of the plane's eight toilets wouldn't flush, AFP reported.
Jammed toilets are a typical reason for passenger flights to divert to the nearest airport.
One 2016 British Airways flight to Dubai, however, suffered perhaps the most drastic plane toilet horror story.
The flight had to return to London's Heathrow Airport due to what passengers said was a "smelly poo" in the toilet, The Telegraph reported.
One man on board, Hertsmere councilor Abhishek Sachdev, said the pilot had called for senior cabin crew to discuss a matter with him. "About 10 minutes later he said you may have noticed there's a quite pungent smell coming from one of the toilet," Sachdev said, per the BBC.
The plane was diverted 30 minutes into its seven-hour trip, according to the outlet.
3. Bird Strikes
Bird strikes aren't rare on commercial flights. At least 272,000 wildlife strikes have been reported by civilian aircraft in the US between 1990 and 2022, the vast majority of which involve birds, per the Federal Aviation Administration.
Planes are more likely to encounter birds when taking off, landing, climbing in the air, or approaching a runway. Bird strikes can often ground flights — the US civil aviation industry was estimated by the Bird Strike Committee USA to have lost around $385 million in 2022 due to wildlife strikes.
For example, two United Airlines flights — one to Las Vegas and another to Chile — were in April forced to turn around and land at Bush Intercontinental Airport in Houston due to bird strikes.
"When we leveled off at 4,000, we heard a loud pop and you could feel something, so we're going to contact maintenance and company. We'll go ahead and continue our climb for now, but we might be getting back with you," one of the pilots told air traffic controllers, per ABC13.
4. Someone forgot their bag
It's unusual for flights to be disrupted because a passenger forgot their luggage, but in the case of a flight heading to Bangkok in July, one pilot agreed to turn around on the runway just before takeoff for such a request.
A tourist complained that his valuables had been left in Chiang Mai International Airport's departure lounge, and argued with flight attendants, per New Zealand outlet Stuff.
The man was removed from the flight, and the passenger, who shot a video of the confrontation but didn't want to be named, said the journey ended up being delayed 45 minutes, according to Stuff.
5. Someone forgot their baby
A Saudia flight from Jeddah, Saudia Arabia to Kuala Lumpur, Malaysia turned around in 2019 when a mother told staff she'd forgotten her baby in the terminal, Insider previously reported.
The pilot told air traffic controllers that the mother was "refusing to continue the flight," Dubai-based outlet Gulf News reported.
"May God be with us. Can we come back?" the pilot said, per the outlet.
The flight was later cleared to return to to the airport, but it wasn't clear from footage of the incident whether the plane was already in the air, Insider reported.
6. A pet was mistakenly let on board
In 2018, a United Airlines flight from Newark to St. Louis was diverted after crew realized that a dog was "mistakenly" put on the plane, ABC News reported.
The plane landed in Akron, Ohio, after which the dog was "safely delivered" to the owner, ABC reported.
A United spokesperson told ABC that all customers on the flight were provided compensation.