A helicopter parent is a term for a person who pays extremely close attention to his or her child or children, particularly at educational institutions. They rush to prevent any harm or failure from befalling them or letting them learn from their own mistakes, sometimes even contrary to the children's wishes. They are so named because, like a helicopter, they hover closely overhead, rarely out of reach whether their children need them or not.
An extension of the term, "Black Hawks," has been coined for those who cross the line from a mere excess of zeal to unethical behavior such as writing their children's college admission essays. (The reference is to the military helicopter of the same name.)