The Adventures of Vin Fiz (by Clive Cussler)

They first use it to make a toy tractor into a real one so their father can use it on the farm. Then Casey turns a model of the Vin Fiz, a plane built by the Wright brothers that was the first to fly across the country, into a real plane, and he and Lacey decide to fly to New York.

Along the way they discover that the plane has a mind of its own, can understand commands, and assorted other bits of magic conveniently revealed when they're needed. Together they foil two gangs of robbers, stop a runaway train, prevent a shipwreck, rescue girls about to go over Niagara Falls, and have other adventures on the way to the East Coast.

An author's note tells about the original Vin Fiz.

Clive Cussler is a well-known author of adult books. But, as often happens when adult writers try to make the transition to kid's books, he underestimates the difficulty -- and his audience. The premise is fantastic enough (kids use a magical plane to stop crime and save lives), but the tone is condescending at best. The story is filled with cutesy names (Ever and Ima Nicefolk, Stoke and Blaze Firepit, etc.), cutesy phrases ("in less time than it takes to say 'dingle, fingle, gingle ...'"), and logical holes big enough to fly a biplane through.

Cussler has a habit of didactically explaining some of his vocabulary. Worst of all, however, is the ending, which reads as if the author just lost interest in his own story. Of course his readers may have lost interest long before that. This may have worked as a bedtime story for Cussler's grandchildren, but as a book, it's weak.