Swing-Wing Mach 3 Interceptor
The proposed French-originated Dassault MD.117-33 project intended to use a swing-wing feature for super-high-speed flight.
Authored By: Staff Writer | Last Edited:
At the end of World War 2 in 1945, the French aero-industry lay in ruins. The German occupation hampered and ultimately destroyed many pre-war and early-war programs and it was the task of several remaining industry players to resurrect a once-thriving industry. Dassault Aviation, established back in 1929 by Marcel Dassault (nee Bloch), was one of the contributors in bringing back French aviation from the dead and many-a-project were developed in the post-war period around the growing acceptance of the turbojet engine.
The concept of the "swing-wing", or variable-sweep wing, was another product of the post-war period. In this arrangement, the mainplanes, or a section of them, could be swept in-flight as needed. The arrangement proved the cornerstone of Cold War (1947-1991) designs such as the American Grumman F-14 "Tomcat" naval fighter and European PANAVIA "Tornado" fighter-bomber (both detailed elsewhere on this site). The ability to "sweep the wing" forward or rearward provided different lift-and-drag properties for different portions of an aircraft's flight envelope - wings with little sweep being optimal for low-speed, low-level flight while increasingly swept-back wings were needed for high-speed flight.
Dassault was one of the few (possibly the only one) French concerns that made any notable progress in this field with several developments based around the concept of a "moving wing". One such product of the period became the "MD.117-33" which most likely appeared during the 1960s as a "paper" airplane. In this proposed fighter/interceptor design, the aircraft had a typical centered, cylindrical fuselage of rather slim form with extended wingroots housing what would become the variable geometry wing controls. The mainplanes were seated well-aft of midships with the cockpit closer to the nose and a single-finned vertical plane used at the tail, which also made use of low-mounted horizontal planes. For ground-running, the aircraft was drawn up with a modern retractable tricycle undercarriage.
The cockpit was to offer relatively good views of the action around the front of the aircraft, though this would be obstructed some by the raised dorsal spine directly behind the seat. Ahead of the cockpit was a slim nosecone most likely to house a radar unit. The canopy was of a two-piece design with light framing and an ejection seat most likely would have been worked into the aircraft at some point.
One of the most distinguishable physical characteristics of this proposed Mach 3.0+ single-seat, twin-engine fighter aircraft were its podded turbojet-housing nacelles. These were installed as close to the body to either side of the fuselage and under the large-area wingroots. Shock cones were featured at their intake ends and exhausting was through conventional circular ports.
Despite the promise offered of this super-high-speed aircraft on paper, there appeared too many design issues to overcome for the MD.117-33 to become a viable player. Notable concerns centered on proper balancing, general air flow, structural integrity of individual parts and sections of the aircraft at super-high-speeds, general engine positioning and arrangement in the overall fighter, and the basic concept of a Mach 3+ capable fighter/interceptor to cover the modest French airspace. With all of that, it appears that the project was not advanced beyond a single official three-view drawing.