Those dogs are trained and won’t attack except on command.
They are animals. You can’t be 100% certain of that. Is the dog trained to handle turbulent flight? Besides, I’m talking about people on the plane who are uncomfortable or just plain scared of dogs. It is a reasonable fear, especially for a person who has been attacked by a dog. To most people, dogs are cuddly pets. To some, they are ravenous wolves—especially breeds that retain a lot of their wolflike appearance.
I think it’s better to say that a trained attack dog won’t attack unless commanded, one of their “triggers” is activated, or the dog feels provoked/threatened.