Not a very well know series but I really enjoyed watching it during my time in the Air Force. I remembered being intrigued with the plane designes and world the pilots operate in. Its a story about two guys and their missions in the artic agains an alien foe with their AI Plane Yukikaze.
The anime OVA was made by Gonzo and they improved their cel rendering techniques with lightwave 6.
Looking at the video you see the went to an actual Airforce base to do their research on aircraft even though they were designing slight modified futuristic airships.
I am not sure where this is streaming or available in bluray
But you can watch it on Jack Sparrow Links here in this Tumblr Post: