The fish's tail fin was hurt.

这条鱼的尾鳍受伤了。

The aircraft has a long tail fin.

那架飞机有一个长长的尾翼。

Remote Functions: climb, descend, and tail fin control.

遥控功能：爬升，下降，和尾翼控制。

Then I noticed a tail fin missing and I realized what was happening.

当我看到一片尾翼飞了出去我才意识到眼前发生了什么。

Add a propeller and a tail fin and it looks exactly like a little plane.

装上螺旋桨和尾翼之后，看起来极像小飞机。