Stability

[bertengineer]

Stability Training
In teaching a lesson on Lateral, Horizontal, and Vertical stability, what is the best method to use? WHat causes the tail to rise and the nose to drop when put into a stall condition?

bertengineer

 

[avbug]

Bert,

There are several factors causing this, and it really depends on the airplane.

For light training airplanes, the most important factor that relates to the pitching moments experienced is the loss of downwash on the horizontal stabilizer. Explain this in conjunction with the angle of attack of both the wing and horizontal stab, and you can show a clear picture of why the airplane pitches nose down.

Use a small model airplane while you demonstrate it. Show a typical download on the horizontal stab, by balanding the model in your hand such that you must push down on the tail to keep the nose up. Then show that down load being taken away by releasing the down pressure on the tail, and note that the airplane pitches down.

Use the small model airplane to show all of your explainations to the student; it makes things more clear. Explain the elements of a stall by discussing holding your hand out a car window when going down the freeway. Everybody has done that, and the relevance of angle of attack will be immediately clear to the student.