http://www.thegnomonworkshop.com/tutorials/designing-a-military-aircraft

Learn how to create a believable 3D aircraft concept from initial sketch to final render using Photoshop, Blender, and 3D-Coat. Nikolai Razuev, a Senior Concept Artist at DNEG, shares his tried-and-tested techniques, starting with his tricks for sketching concepts in Photoshop and discussing the basic design principles that he follows when designing for the entertainment industry.   Throughout 6 chapters, Nikolai details the efficient techniques for designing, modeling, and texturing realistic flying vehicles using 3D-Coat and Blender, from shape design and shading the initial 2D sketch to rough modeling in 3D-Coat, and applying realistic shaders using 3D-Coat, Nikolai uncovers his complete process for detailing a believable concept. He finishes with some photo-bashing using Photoshop over the top of his 3D render.