Four times a year, British Aaran Stewart must make his way through London’s Heathrow airport to attend the Boston Higashi School in Randolph, Mass. However, his severe autism and obsessive compulsive disorder makes the otherwise annoying transit completely unbearable. To alleviate the inevitable stress and anxiety, Heathrow staff has begun to run a truly heartwarming con.

Every time the 21-year-old travels from the airport, he is greeted by the same staff at the same check-in counter. He then visits the same shops and departs from the same gate. Onboard, he is always assigned the same seat. For the past five years, each trip has been a flawless recreation of the first.

"Without the procedure we wouldn't be getting on the plane,” Aaran’s mother, Amanda, told Radio 4. “It has to be carried out absolutely pristinely otherwise we'll end up with a problem."

Unless the bus from gate A10 doesn’t display flight number BA215, Aaran won’t get on. One time, a screen malfunction almost made them miss their flight. Fortunately, the driver was able to swap buses.

"It's routine-based. If there are any delays he'll think you're going to try to change something which will then panic him. When we get to the gate he'll settle,” Amanda said. "Everything's gone to plan, he'll wait for the bus, we've got the seats we need and we're off!"

Disability consultant Geoff Adams-Spink commended Heathrow’s willingness to accommodate Aaran’s condition. Speaking to BBC News, he said that airports often fail to understand that every disability is different. Many require personalized accommodation.

"Hats off to the people who organize it,” he said. “All too often it's wheelchairs all round and it doesn't matter what your disability is, someone will turn up with a wheelchair and can get quite irritated if you don't sit in it.”

Autism spectrum disorder (ASD) refers to a group of complex brain disorders that impair the ability to modulate along social contexts by restricting communication and emphasizing repetitive behavior. For individuals with ASD, a calm, well-structured environment is usually crucial. To learn more about the condition, visit The National Autistic Society or Autism Speaks.