 While this did result in fuel savings, the main reason not to use afterburner during carrier launches was that if an engine failed the F110's thrust in full afterburner would produce a yawing moment too abruptly for the pilot to correct.Thus the launch of an F-14D with afterburner was rare, while the F-14A required full afterburner unless very lightly loaded.Although the F-14D was to be the definitive version of the Tomcat, not all fleet units received the D variant.