additional thrust fin的用法和样例：
- rudder with additional thrust fin
- additional thrust fins
- This additional thrust was important for Stricklin, because he had left the plane only 40 feet off the ground.The burst gave him a 100-foot cushion.
- The results showed that cap-manometer can avoid the errors caused by liquid fluctuation and turbulence at a low gas velocity, and prevent an additional thrust head at a high gas velocity.