The Public Works Department has written five major European and U.S. fighter jet makers to survey potential replacements for Canada’s aging fighter fleet, including the Lockheed Martin defence firm which is testing and developing the controversial F-35 stealth fighter jet, but the end result is likely to be only a ‘market’ analysis of costs and aircraft abilities, according to critics of the F-35 project and to a major U.S. aerospace firm that is taking part in the review.