This sketch is by David Michael Beck, a veteran illustrator who's career has spanned all sorts of markets and all sorts of work, from comic books to advertising, to institutional work, to graphic design. According to the bio on his website, he has worked for Marvel, DC, Top Cow, and Dark Horse (in the comic book world), on titles as varied as Red Sonya, GI Joe, and Buckaroo Banzai.
I am not really familiar with Beck's work but this Hawkman looks very dynamic. I like the lithe form of the body, which retains it's power despite the ease with which it seems to move. The wing harness seems a little too small, but the feather work is nicely detailed. I do like the details, like the ornate studs on the shield, and the way the strap for the morningstar pulls against his wrist. All in all a nice piece, with good strength and fluidity.
Disclaimer: I do not own or have possession of this sketch. It is being reposted from the cited website only.
Image: Hawkman sketch, ???, David Michael Beck, retrieved from Catskill Comics.