Back Pressure - The term back pressure is used in flying to mean "up elevator" or pulling back on the control wheel to make the airplane go up. In RC flying it means pulling back on the stick to make the airplane go up. Typically you add a little "back pressure" in a turn to maintain altitude, to climb after takeoff, and you add back pressure when you "flair" when landing.

Flair - Flair refers to one of the last control inputs you make when landing an aircraft. It occurs at the very end of the landing approach when you "flair" or give up elevator (add back pressure) just before touchdown. The idea on landing is to touch down as lightly as possible at a relatively slow airspeed.

Landing Approach - The landing approach is the base-final approach segments of the traffic pattern. It is very important to have a "stabilized" approach to ensure a successful landing. A bad approach often results in a poor landing, a crash, or a "go-around". The way you ensure a stabilized approach is to fly the base and final segments as accurately as possible. Being too high, too low, off centerline, too close in, too far out, too fast or too slow can all result in a "unstabilized approach" with the possibility of a "bad landing". 

Power - Power in flying refers to adding or decreasing throttle. For instance, you add power when taking off, climbing, or making a go-around. So if your instructor asks you to "add power" he wants you to increase the throttle. He may also ask you to decrease the power or cut back on the throttle. 

"Two" Mistakes High - The term "Two" Mistakes High refers to the altitude the instructor wants you to be at in case you make a mistake and he has to take control of the model. Normally this altitude is fairly high to provide a "cushion" to recover the model before it crashes.

Go Around - This is the maneuver that is made when something goes wrong on final approach and you decide not to land but to go around and re-enter the traffic pattern and try the landing again. When the instructor says "go around", don't hesitate; add power and climb out straight ahead and enter the downwind again.

Buddy Box - The "buddy box" training system is the most widely used system in training student pilots. It's advantage is safety. The system involves connecting two radios (the primary radio and the "buddy box" radio) together with a trainer cord. The instructor is then able to let the pilot have control of the model by simply depressing a button on the primary radio. If the instructor wants to regain control, he simply releases the button and the model will only respond to the primary radio. Care must be taken to:

1. Determine that the two radios being used are compatible with each other. 
2. Synchronize the two radios while on the ground to adjust the trim settings and ensure servo reversing functions are the same on both radios. 
3. Have the "buddy box" radio turned off or on depending on the recommendations for the radios being used.

CG - The term CG stands for Center of Gravity. This is the balance point of the airplane. Care must be taken to ensure your model is within the CG limits prescribed by the manufacturer. A worst case scenario can involve a model that is so tail heavy that it goes out of control and crashes. Nose heavy is not good either but usually you can fly a nose heavy model without crashing.

Workmanship - Doing a good job of building your model and maintaining it after it is built is very, veryimportant! Countless crashes could be prevented by ensuring best building practices are followed. 

Two "extreme examples" of "not following best building practices" include:
1. Ironing on the MonoKote "without" removing the clear protective film. The model literally "exploded" after making the first turn with all the MonoKote blowing off. 
2. Two wing halves were joined using 5 min Epoxy. No problem except; the builder ONLY USED "1" part of the "2" part Epoxy. The wing failed immediately after takeoff!!!!