Weeks after a teen with autism and her family were booted from a United Airlines flight, advocates are calling on federal authorities to remind air carriers of their responsibilities.

The Autistic Self Advocacy Network is asking the U.S. Department of Transportation to issue guidance detailing how the Air Carrier Access Act applies to travelers with autism and other special needs.

“Autistic individuals and their families frequently face barriers to accessing air travel, either because of unfair assumptions about their ability to fly safely or because their requests for seating, preboarding, security screening or other accommodations are not respected,” wrote Ari Ne’eman and Samantha Crane from the self-advocacy group in a letter sent Thursday to Secretary of Transportation Anthony Foxx.

“We ask that DOT clarify that — as with all disabilities — autistic individuals should not be denied access to flights based on their posing a ‘direct threat’ to health and safety based solely on their diagnosis, or based on risks that could be mitigated through reasonable modifications of policies and procedures,” the letter said.

The request comes after an Oregon family went public earlier this month after they were kicked off a United Airlines flight.

Donna Beegle said she requested to purchase a hot meal to calm her daughter Juliette, 15, who has autism and is nonverbal, during their flight home from Disney World. After 25-minutes of back and forth with a flight attendant, Beegle said she was finally able to obtain one of the first-class meals, which did put her daughter at ease. However, a short time later, the plane made an emergency landing in Salt Lake City and the family was escorted off by police.

News of the incident sparked national attention and Beegle said she plans to sue.

The Autistic Self Advocacy Network said the family’s experience highlights a larger problem.

“The ACAA was meant to cover all people with disabilities,” said Crane, the group’s legal director and director of public policy. “Unfortunately, we’re seeing many situations in which airline staff either don’t understand or don’t follow the law.”

The self advocacy organization wants the Department of Transportation to provide guidance that includes examples of “reasonable modifications” that airlines ought to make for travelers with autism.

Officials with the Transportation Department told Disability Scoop that they have received the letter and are looking into the matter.