Other airlines have been buying Apple's iPad for that purpose.
Delta says the Surface tablets will save $13 million per year in fuel and other costs. Right now, each pilot carries a 38-pound flight bag with manuals and maps.
Delta is testing the tablets on its Boeing 757s and 767s, which are flown by the same group of pilots. Delta is hoping for Federal Aviation Administration approval next year to use them throughout the flight, and it hopes to have approval for all of its other planes by the end of next year.