Last week I stalled my Piper Cub and this was the first time this has happened to me with any plane.The engine was still running but i felt I had no power over the plane. I throttled up and regained power. What happened and what causes stalling?
Thanks
Jeff

Loss of lift.

The wing takes the plane's forward speed, and transforms some of it to Lift and some to Drag. When lift exceeds the plane's weight, the wing will hold the plane off the ground.

As speed reduces, lift reduces, and when the wing's lift no longer exceeds the weight, the plane falls out of the air. Hopefully, you're near ground level, over a landing strip, at the time.

There are other ways to reduce lift. Bank 60 degrees, and lose half your lift. Pitch up steeply, and you lose lots of lift.

I suspect you just let your forward speed fall below "stall speed", that point where lift does not exceed weight.

Good luck,
Dave Olson

Well, more appropriately, it isn't when the wing's lift doesn't exceed the weight, certainly a controlled descent is one where the lift is less than weight, etc.

The stall happens when the wing reaches an angle of attack, usually along with a slower airspeed, at which the flow over the wing separates, resulting in the wing no longer producing the lift it was. There is still lift being generated but it is significantly less. The speed at which this occurs is usually low but is a function of the angle of attack that the airplane is flying at.

The typical sport airplane will stall, pitch forward with some altitude loss and as the speed increases the flow will reattach and it will start flying again.

There are special cases like the modern 3D airplane that takes advantage of the wing's ability to produce lift in the fully stalled condition. They fly many maneuvers based on this along with some thrust help.

The big problem that can happen with a stall is when it is asymmetrial and rolls the airplane into a spin. Especially bad when you are about 10 feet lower than the altitude needed to recover. It makes it prudent to have fairly small control inputs when doing a landing approach to not force the airplane into the stall.

Practice doing stalls at altitude in order to know when they might happen and to avoid those flight conditions.

Jeff, I'm assuming from this statement that you're a fairly low time pilot if this is the first time you've experienced this. What you described is typical of any aircraft of any size when the speed is allowed to drop. There's nothing "wrong" with the model at all. It's just how they feel when there's not enough airflow to fly and the controls get really mushy from the low speed. Rather than avoid it I'd suggest you play with it to better learn what it feels like and how best to control the models during low speed flight. This performance region has it's own rules about what you can do and how the model reacts and it carries it's own fun and rewards when you master it.

For example at this speed and angle of attack region you'll likely experience adverse yaw where using the ailerons causes the model to roll one direction and yaw the other. With enough aileron you may even promote a deeper stall on the aileron down side and have the model drop into a spiral dive opposite to your control input. The response to this is to use a LITTLE aileron and also coordinate in some rudder with the aileron. With that the model will respond with a more normal action. Another fun item is hovering about 5 to 10 degrees nose high into the wind at minimum airspeed and with just enough power to prevent a deep stall where the nose drops away. With the right model and wind it'll look like it's stuck there or even flying backwards.

In any event learning to fly your models in the lower speed region will not only make you a better pilot but it's fun as well. For obvious reasons lighter models will do best in this mode but any model can be used and it should be so that if something goes wrong during a landing approach you are better equipped to deal with it.

Ben Lanterman hit the nail on the head. When I was in my aviation classes at Purdue, this was one of the quiz questions we got all the time. The answer that people are quick to jump on is that "the airspeed is to low and the wing is not producing enough lift to keep the aircraft in the air. While this is true, there is more to it than that as Ben states. A stall can happen at any speed, high or low. A stall occurs when the angle of attack causes a disruption of airflow over the top of the wing resulting in the loss of lift. Three types of stalls: Departure Stall(Power on Stall), Arrival Stall(power off stall), and Accelerated Stalls.