IO540...
Still on the subject of busts, how many serious level busts were done last year by CAT (that's two "professional" pilots in the cockpit) ?
Getting a bit off topic but you'll probably find what you're looking for at the
Level Best site.
You won't find me arguing against GPS though it is always useful if folk do know how it works, some of the gotchas and also databases are kept up to date.