Many factors affecting stall speed (make sure they know what kind of airspeed you are discussing) can be explained by simply describing the current angle of attack (depending on the situation, i.e. fwd CG, aft CG, heavy, etc.) versus the critical angle of attack at which an aircraft stalls. The higher AOA that results from a forward CG/heavier weight/high load factor is closer to the critical angle of attack than in a lower weight/aft CG. Therefore less distance to go to reach the Crit. AOA. Students like pictures, compare the Crit AOA and the current AOA on a diagram for a given situations.
The student needs to understand that the aircraft will only stall if it exceeds the critical angle of attack. If you can convey that to the student and relate the different AOA situations, it should be easy to understand.
For load factor, first lay out the definition both by text and using illustrations...keep it simple, I usually simply tell them it's the weight imposed on the wings, G force. You can use the Vg diagram if you wish for further "advanced" understanding. Again, relate back to what they know about load factor...where do they experience it the most? Using turns as an example is probably the best explanation. In a turn, what happens to the load factor or G's? Increases. Why? To maintain the vertical component of lift that is lost in the turn, for level flight, we need to increase AOA (and power) which imposes a force or G on the aircraft. Again, this puts us closer to the CRITICAL AOA.
That's probably the most basic that I tought. You really have to make sure the student has an understanding of the terms you are using, i.e. Crit AOA, AOA!, Load Factor, Forces, CG, etc. before you begin this explanation. You should probably already have an idea of the student's knowledge level if you worked with him/her in the past.
1. Keep it simple
2. Don't pull fancy aerodynamics
3. Remember go from the known to the unknown
4. To tell you the truth, some of the best ways to teach this is actually do the stalls in the different situations. Besides I really think this will reinforce what you discussed on the ground and get right down to business as to what they really should know about stalls-- where do we get into them and how to recover/avoid them. Probably the most important.
Good luck and have fun.
AeroDMB
