按时间顺序显示合并的Wordpress查询

How can I get the actual $first_ids to display first and then show $second_ids. With this code, it still orders them. Not sure what they are ordered by, I am guessing Wordpress defualt sorting?

What I am trying to achieve is that I added the tag "Featured" to all posts inside a custom post type "aircraft-refueling" and I want to display all the "Featured" posts first and then show the rest of the posts.

<?php
// first query
$first_ids = get_posts( array(
    'fields'         => 'ids',
    'posts_per_page' => '999',
    'post_status'    => 'publish',
    'post_type'      => array('aircraft-refueling'),
    'tag' => 'featured'
));

// second query
$second_ids = get_posts( array(
    'fields'         => 'ids',
    'posts_per_page' => '999',
    'post_status'    => 'publish',
    'post_type'      => array('aircraft-refueling'),
    'tag__not_in' => array('592')
));

// merging ids
$post_ids = array_merge( $first_ids, $second_ids);

// the main query
$query = new WP_Query(array(
    'post_type' => 'aircraft-refueling',
    'post__in'  => $post_ids, 
    'paged'     => $paged
));
?>

I figured it out. After you merge the queries, on the third one you have to add

'orderby' => 'post__in', // Preserve post ID order given in the post__in array (available since Version 3.5).

and that puts the posts in the order that it retrieved in from the merged post array.