A Tennessee-bound United Airlines plane returned to Chicago airport, Illinois, mid-flight after the pilot realized the aircraft was “too large” to land in the destined airport.

The unusual incident took place on Oct. 16, when the pilot of United flight 5277 told the passengers on board that he would be turning the plane around and heading back to O’Hare International Airport, Chicago because the Metropolitan Airport at Chattanooga, Tennessee, was not prepared to handle the size of the plane.

In addition, two text messages were sent to all the passengers from the airline company explaining more details about the situation. One of them read: "Your 2:13 p.m. [local time, 3:13 p.m. EDT] United flight to Chattanooga is delayed because of unforeseen circumstances. This is an unusual situation and we're working hard to solve it. We value your time and we're sorry for the inconvenience.''

Another one added: "We're sorry for returning to Chicago. The airport in Chattanooga is unable to assist with ground operational requirements for your current aircraft type. We assigned your flight a new plane."

Vince Fallon, one of the passengers present on the flight, told USA Today that there had been a last minute change of aircraft at the O’Hare Airport prior to take-off due to a mechanical issue. Despite having their seats reassigned after shifting from a regional jet to another, there was hardly any delay in take-off.

The flight which was deemed “too large” for Chattanooga was a 76-seater Embraer 175, although only 50 of the seats were occupied on the plane.

While the flight was originally supposed to land at Chattanooga at 5 p.m. EDT, it came back to the Chicago airport at 4:29 p.m. (5:29 p.m. EDT). As the new flight was scheduled to fly after an hour, the passengers were treated to Cheez-Its, pretzels and water.

"We still were only told that there was a mistake, saying we could take the larger plane to Chattanooga, but no real explanation,'' Jill Lohsen, another passenger on the flight said.

Finally, the passengers were relocated to a 50-seater Bombardier CRJ 200, which the airline typically used when flying from Chicago to Chattanooga. The flight arrived at its destination around 8:30 p.m. EDT, more than three hours after the originally estimated time of arrival.

All the passengers received refunds for the Chicago to Chattanooga leg of the journey as well as $300 flight voucher or air miles for their trouble.

Lohsen said she could not make much sense of the pilot’s decision to make a U-turn as she claimed she had flown on similarly large Delta Air Lines planes which always landed successfully at Chattanooga.

“The pilot, nor the flight attendants, did not have any information for us and just kept saying they would figure it out when we land,'' she said.

According to the Points Guy, one of the runways at the Chattanooga airport was 7,400 feet in length, which was more than sufficient to land an Embraer 175, which required a minimum runway length of 4,130 feet. The airport also reportedly had taxiways which could accommodate a Boeing 757 — an aircraft more than twice the size of an Embraer E175.

A spokeswoman for United Airlines partner SkyWest Airlines, Marissa Snow, vaguely mentioned the reason for the plane’s turnaround as the Embraer E175 being "just a different aircraft than typical for ground personnel there.''  She did not mention why the airline had not checked to find out about the lack of capable ground crew at the destined airport prior to taking off.

United Airlines A Tennessee-bound United Airlines plane returned to Chicago airport, Illinois, midflight after the pilot realized the aircraft was “too large” to land in the destined airport. In this photo, United Airlines planes sit on the tarmac at San Francisco International Airport, California, July 8, 2015. Photo: Getty Images/ Justin Sullivan