Work on the Mono Tiltrotor (MTR) was initiated in 2004. A concept study was performed under an
Office of Naval Research contract and this study concluded that the MTR, if technically realizable, would be half the size and one-third the weight of legacy helicopter concepts for a mission. In 2005 and 2006, design of the 9400 pound
gross weight MTR Scaled Demonstrator (MTR-SD) was performed under a
United States Army contract at the
US Army Research Laboratories. This work included the following tasks:
engine selection;
transmission design; hub, controls, and blade preliminary design; comprehensive performance and
aeroelastic analysis; analysis of critical
stress concentrations; conceptual design of the fixed wing and cargo pod;
wind tunnel testing of wing deployment; and
longitudinal static stability analysis from
hover through
cruise. This work resulted in a definition of each component's and each subassembly's weight,
moments of inertia, location on the aircraft, and
aerodynamic drag. The predicted range and speed were derived from this aircraft design data. In 2007 and 2008,
demonstrations and
validations of the MTR-SD design were performed under an Army contract. The three unprecedented hardware mechanisms of the MTR were demonstrated in small scale flight tests: 1) the
aerodynamically deployed wing panels; 2) the
pitch axis suspended cargo pod; and 3) the tilting centerline rotor. Furthermore, a
diameter rotor
remote control MTR Functional Demonstrator (MTR-FD) that integrates these three features was designed, built, and hover tested.
Bell Helicopter Textron used proprietary methods for advanced concept design and analysis to validate the rotor MTR-SD design. Bell Helicopter's assessment resulted in validations of the MTR-SD vertical lift capacity, engine power required and power available, cruise thrust and propulsive efficiency, aircraft weight, and airplane mode cruise lift. Bell Helicopter also generated and reported MTR-SD
flight dynamics data. A
computational fluid dynamics drag assessment was performed, and in combination with the Bell Helicopter assessment this validated MTR-SD projected drag and aircraft cruise range performance. and in the Office of Naval Research – Cargo Unmanned Aircraft System – Request for Information (ONR Cargo UAS RFI). In early 2010, under a multi-year contract with the Office of Naval Research (ONR), the CONOPs and aircraft design were refined for Navy shipboard compatibility. On October 2, 2010, the first full conversion between helicopter and airplane modes of flight was achieved using a revised Mono Tiltrotor - Functional Demonstrator (MTR-FD), 4 foot diameter, small-scale remote control model. ==Specifications==