ill give away my secret....
with a trackball its never gonna happen.... doing it how it says to at least...
instead try this....
step one:
click oncce on the plane and drag it to the vary tip top corner to where you can barely see it...
step two:
move the cursor off the screen to the side and then move it out of the window
step three:
move it around tothe other side and bring it into the window again and when you bring it back onto the screen the plane will shoot like a batt out of hell..... its not really easy at first cause you have to learn how its going to dip as you said.... i found that bringing it back on the screen right above the white line in the lower gray scale area is where to do it... good luck and once you figure it out you will have 100+ runs every time...