Boeing's 2001 patent[1] detailed the breadth of delta wing-canard concepts studied, which included a supersonic variant with four engines capable of cruising at Mach 1.5 to 3.0,[10] various tail, engine location, and inlet and outlet configurations,[11] smaller supersonic and subsonic business jets,[12] and what Boeing called a "modular" system, where the cruise speed could be changed from supersonic to near-sonic by an interchangeable nose;[13] the "Sonic Cruiser" was a near-sonic variant.[14] The origin has been traced back to 1995, with the formation of an internal Airplane Creation Process Strategy team, which had designed a plane code-named Project Glacier that strongly resembled the initial Sonic Cruiser drawings by fall 2000.[7] In early 2001, Boeing CEO Alan Mulally began privately publicizing the concept to potential customers, touting its improved speed at an efficiency similar to existing designs.[4]