At least 250 pilots are estimated to be hired this year by the Big Four fractional providers, according to Aviation Information Resources (AIR). This is about 50 more than were hired last year. If the estimate turns out to be accurate, it will reverse a slide that frax hiring has been on since the Atlanta-based firm began tracking the employment situation at such operators four years ago. AIR figures show that hiring by the major fractional providers nose-dived from 1,363 in 2000 to 198 last year.