Business.gov : Aerospace and Defense - Guide to complying with laws and regulations that apply to U.S. Department of Defense contractors and manufacturers of aerospace products, including civil and military aircraft, missiles, space vehicles, military equipment, and auxiliary equipment, parts - http://www.business.gov/topic/Aerospace_and_Defense/
WorldbidAerospace - Trade leads and private and government tender opportunities for aerospace projects and equipment. - http://worldbidaerospace.com/