the horizontal plane of the disc fig3 a is a close up depicting the tilt of the booms with respect to the horizontal plane of the disc airfoil the booms are tilted upward between 1 degree and 1 5 degrees from the horizontal plane fig3 a also indicates the approximate location of the optimum ballast location 37 and the center of gravity 38 of the aircraft although the model space craft would glide efficiently under virtually all conditions the ability to perform acrobatic stunts with the model craft disclosed in british publication 2270478 was limited it was determined that the booms presented to some extent a u201c bluff body u201d profile to the onrushing slipstream which resulted in air deflection with eddy currents and thus increased drag a u201c loop the loop u201d acrobatic stunt with the model was difficult to achieve consistently to achieve a u201c loop the loop u201d the model needs to be thrown fast knowing that the disc airfoil is fixed in place i e not rotating like a frisbee there will be a great deal more turbulence so an increase was made to the height of the booms with respect to the airfoil disc this specific.