03/31/2006. Remarks by Johan Visschedijk: "This is one of three aircraft (s/n 30-161 to 30-163, c/n 668 to 670) produced as staff transport, and was based at Crissy Field, San Fransisco, California. Power came from a 600 hp Curtiss Conqueror V-1570-7 V-12 liquid-cooled engine. Note the counter-clockwise propeller rotation."