Yes to it being airbrushed. I kept it a bit sloopy because "Orks"
I wish I had taken the time to take WIP pics, but I can at least walk you through the steps
For the plane it was a prime with Duplicolor Sandable Primer then I painted the whole plane in Mephiston Red followed by a Agrax Earthshade wash and Evil Sunz Scarlett drybrush.
Metal is Boltgun with 2 coats of Agrax and a light drybrush of Boltgun and then lighter of Runefang (silver) and the bronze/brass, is based in Boltgun, then a coat of Sycorax Bronze, and 2 coats of Agrax then a light drybrush of Runefang.
I then airbrushed the wings and tail vallejo model color black (best black in the business in my opinion) and then went to weathering.
I lined the armor plates with Runefang, making sure to keep it rougher than a normal lining. Then I took Nuln Oil Gloss and stared making oil streaks along the body.
Then the checks, dags, and flames. Just painted white on the black and red...2 to 3 coats is easy when they are small shapes. I then finished off thearking by washing them with Agrax and splotching it with a brush and/or finger to keep it from settling on the larget flat surfaces which turned it into a filter more than a wash making a dirty white instead of a light brown.
The pilot was painted Deathworld Forest, Elysian Green, and Ogryn Camo very lightly on his face.
Base is bleached bone, Gryphonne Sepia, and small splotches of Agrax to break up the large surface, which was followed up with a bleached bone drybrush, aird static grass and the earth green clump foliage.
On a side note...best PVA glue you can find, at a decent price....Titebond with the red label
I work on guitars in my spare time and no pva glue wormks better. I have yet to have a single issue with basing material flaking off.
Home Depot and Lowes carries it.
I suggest giving it a shot.