Staff Writer (Updated: 8/29/2016):
The armed UH-1 was only an interim solution for it lacked appropriate crew protection and the battlefield survivability required. This pressed American helicopter makers into developing more dedicated gunship concepts which led to Bell Helicopters to pursue the D-255 "Iroquois Scout" in 1962. The design incorporated a 40mm chin-mounted automatic grenade launcher, ventral 20mm cannon, and wing-mounted rocket/missile launchers. Its crew of two sat in tandem, helping to promote the slimmest of frontal profiles to make for a harder target to hit head on by ground-based fire. The United States Army liked what it saw and awarded a contract for further development late in the year. An early testbed for the concept was born from a modified Bell Model 47 which became the Model 207 in its finalized form. First flight was in July of 1963.
While a promising venture, the Model 207 was not the soundest of solutions for the growing U.S. Army need. The situation in Vietnam was becoming ever more perilous with a greater American military commitment seen as unavoidable. To further a more final solution, the Army pushed forth the "Advanced Aerial Fire Support System" (AAFSS) as an open competition for its gunship helicopter requirement - the product now being termed an "attack helicopter". One of the key participants of this program became Lockheed and its work begat the infamous AH-56 "Cheyenne" - the company's sole attempt at a helicopter design.
While work slowly progressed on the AH-56, the U.S. Army was still in need of an interim solution for the ongoing war and eventually entertained several possible products from the usual suspects - Bell, Boeing-Vertol, Kaman, Piasecki, and Sikorsky. Bell had furthered along a new attack helicopter concept as a private venture born from the Model 207 and incorporating as many mechanical components of its successful UH-1B/C "Iroquois" series as possible to produce the all-new Model 209. First flight of this product came on September 7th, 1965. In April of 1966, this submission won out against its competitors as it was formally selected for production by the Army under the designation of AH-1G "HueyCobra". As it was considered a direct part of the existing UH-1 line ("H-1"), the HueyCobra was born through the "G" model designation and not the expected "A".
As built, the Model 209 prototype featured a look not unlike its final Cobra attack helicopter form. The pilot and weapons specialist sat in a tandem cockpit (pilot in rear) with a large-area, armored canopy offering excellent vision. The cockpit was set behind a short nose assembly and a turreted weapons station was mounted in a traversing chin fairing. The profile was, of course, as slim as possible and a sole turboshaft engine installed aft of the cockpit. The engine drove a two-blade main rotor overhead and a twin-blade tail rotor at rear. The tail rotor was fitted to portside along the single vertical tail fin. Horizontal planes were featured along the sides of the tail stem. Wingstubs sat at the sides of the fuselage to provide an inherent weapons-carrying capability. The undercarriage was of a retractable skid arrangement. The Army offered up some revisions to the Model 209 before serial production ensued and these included a lighter weight plexiglass canopy, a shift of the portside tail rotor to starboard, fixed landing skids, and wider main rotor blades.