Twenty Fourteen - Remove Fixed Menu

function twentyfourteen_remove_masthead_fixed( $classes ) {
	$return = array();

	foreach ($classes as $class) {
		if ($class != 'masthead-fixed') {
			$return[] = $class;
		}
	}
	return $return;
}
add_filter( 'body_class', 'twentyfourteen_remove_masthead_fixed', 999, 1);