If the plane is designed to fly slowly, use a long, low pitch propeller to see the best possible performance.
如果该飞机的设计飞行缓慢，长期使用，低螺距螺旋桨看到最好的性能。
2
Programming by the plane curve unwrapped from the helix curve and cutting layer by layer, we created the variable pitch screw on the 3.5 axis NC milling.
文章基于3.5轴数控铣床，利用螺旋线展开的平面曲线编程，分层切削，加工出变螺距螺纹；
3
The thesis makes a main study of submarines' depth and pitch control in vertical plane and researches on submarines' equilibria control performance.