A Delta Boeing 767 made an emergency landing after its exit slide fell off midair

• A Delta flight from NYC to LA had to turn back after its emergency exit slide detached.
• The Boeing 767 landed safely at JFK about an hour after taking off.
• It is the latest in a string of safety mishaps to befall a Boeing plane.

A Boeing plane was forced to make an emergency landing on Friday after an emergency slide fell off the aircraft.

Delta Air Lines flight 520 from New York's JFK airport aborted its trip to LA on Friday and landed back where it started.

It touched down again at around 8:30 a.m., just an hour into its journey, according to the tracking site Flightradar24.

"After the aircraft had safely landed and proceeded to a gate, it was observed that the emergency slide had separated from the aircraft," a Delta spokesperson said in a statement to NPR.

The airline didn't offer any detail on when, how, or why the slide detached — or where it ended up.

The Delta spokesperson said the airline was "fully supporting retrieval efforts and will fully cooperate in investigations."

In a second statement, Delta said that the incident set off an emergency alarm.

The cabin crew had been alerted by a "flight deck indication related to the right wing emergency exit slide, as well as a non-routine sound from near the right wing."

"As nothing is more important than the safety of our customers and people, Delta flight crews enacted their extensive training and followed procedures to return to JFK," the Delta spokesperson said.

"We appreciate their professionalism and our customers' patience for the delay in their travels."

No injuries were reported aboard the aircraft, which had been carrying 176 customers, two pilots, and five flight attendants.

Delta Air Lines did not immediately respond to a request for comment from Business Insider, sent outside regular working hours.

In a statement, the Federal Aviation Administration said "Delta Air Lines Flight 520 returned safely to John F. Kennedy International Airport in New York around 8:35 a.m. local time on Friday, April 26, after the crew reported a vibration."

"The FAA will investigate."

Delta said it had removed the plane in question from service.

It was a Boeing 767-300ER plane, delivered to the airline in 1990.

According to Flexport, a global logistics workflow company, an aircraft is generally assumed to be operable for an average of 30 years before it is decommissioned, which would put this one at the older end of its service life.

The incident is the latest to hit Boeing following a series of other safety mishaps.

In January, the aircraft maker was forced to ground its fleet of 737 Max planes after a door plug blew out on an Alaska Airlines flight that took off from Portland, Oregon.

The disaster wiped nearly $30 billion off Boeing's market value and saw share prices plummet by as much as 20 percent.

Boeing was also thrust into the spotlight on Capitol Hill by testimony from whistleblowers who told a committee they were met with death threats when they tried to flag safety concerns with their superiors.