The document featured in the image gallery above was submitted by Bell Aircraft Corporation to the Navy Bureau of Aeronautics (BuAer) in 1955 in connection with the company’s efforts to land a contract for a VTOL fighter, which it ultimately did with its D188/D188A designs of late 1956. Titled simply as “VTOL: Vertical Take Off and Landing,” it was intended to illustrate the company’s experience and know-how in the vertical flight domain, providing an interesting overview of Bell’s major VTOL projects as they stood in October of 1955; these were the more promising types that had been examined by the company over the previous three years.
According to the introduction, Bell conducted extensive investigations into the entire spectrum of VTOL aircraft types, including “tailsitter” and “horizontal attitude” configurations, as well as turbojet, turboprop, ducted turboprop, and fanjet propulsion systems. In 1952, the company determined that the horizontal attitude configuration employing rotating-thrust-line type propulsion had the greatest potential for VTOL military aircraft. This was based on safety, ease of flying, simplified ground handling, and insensitivity to surface winds. Bell claimed that these aircraft could make a short rolling take-off carrying a payload substantially greater than possible when operating as VTOL aircraft, this last feature contributing tremendously to the operational flexibility of the vehicle.
Types covered in the brochure include the Bell Air Test Vehicle, an experimental proof-of-concept vehicle built in 1955 to study VTOL aircraft control at low speeds; the D174 Horizontal Attitude Test Airplane, the study that immediately preceded the X-14 research aircraft; a small Reconnaissance and Observation Jet which also shared the X-14 configuration; a Ducted Propeller VTOL test vehicle reminiscent of a stripped down Doak VZ-4; a large Ducted Propeller VTOL Assault Transport; and the D-139 VTOL Day Fighter, a predecessor study to the D188 presented to the Navy the following year. To read more about these projects, please click through the image gallery above, which presents the entire brochure in detail.
It is interesting to note that except for the Bell Air Test Vehicle, none of the designs presented in this document ever left the drawing board, at least in the forms shown here. (Bell would build a ducted fan transport in the form of the X-22A, but it differed considerably from the Ducted Propeller Assault Transport in the brochure). Since the heady days of the 1950s, Bell’s fortunes in the VTOL aircraft field have waxed and waned, with the company ultimately succeeding in the 1980s in getting one of its unconventional concepts into production, namely the V-22 Osprey. However, that program has proven to be both expensive and controversial, and time will tell if the aircraft is ultimately judged to be a success or something less than that.
All images from NARA Archives II, College Park, MD, RG 72
“VTOL: Vertical Take Off and Landing,” Bell Aircraft Corp. Niagara Frontier Division October 1, 1955, in the files of the National Archives II at College Park, MD, RG 72