Too Steep Of A Climb!
A Stall: The Air Does Not Move Over The Wings At A Proper Angle Of Attack & The Wings Lose Lift
When the wings stall, the airflow over the wings has been disturbed. The airflow across the “airfoils” — primarily across the wings from front to back — are no longer holding the airplane up.
If you are watching a seasoned pilot or a student pilot practice an aerodynamic stall, you will see the airplane noses up and then gently dips down.
When the airplane by pitches down, the pilot, or the automated mechanism of the airplane, is actually attempting to recover from the stall.
Then in order to get the wing flying again, the pilot has to move the control wheel forward — which seems counter-intuitive. Nevertheless, the pilot must get the air braking over the wings again at a proper angle of attack to create lift again.
If you watch an airplane take off, you will see that it raises its nose into the air at a certain point in time and speed. Without getting too technical, that airplane attempts to lift its nose to somewhere around 17 degrees relative to the airflow. An airplane stalls when the angle of attack of the wings exceeds something around 17 degrees.
Have you see pictures of airplanes “buzzing” the ground. They are diving toward the ground, and then they suddenly pull up and out. If at the bottom of that dive you pull up too quickly and change the airflow across the wings, you face the possibility of stalling that airplane.
Such dives are dangerous because a pilot can lose the necessarily aerodynamic lift on the wings when it attempts to pull the nose up and out of that dive. The engine can be running full-bore — the propellers or jets can be wide open — but when the angle of attack of the wings exceeds the critical point — the necessary lift exerted on the wings has been lost and the airplane aerodynamically stalls.
When attempting to pull out of the dive, the airflow is no longer sufficiently moving from the front or leading edge of the wing, across the wing, and then to the wing’s trailing edge.
If you do not have the altitude to recover from the stall — the altitude needed to keep the nose within that 17-degree angle of attack as you pull the nose up — you will very likely crash the airplane.
You cannot pull the nose of your airplane up without changing the flow of air across the wings. If you pull it up too “quickly” as you attempt to come out of your dive, you are stuck with little to no altitude to possibly recover. The wings will no longer exert lift, and that is the definition of a stall!
Forty percent of fatal stall accidents begin when an airplane is below 250 above the ground and the pilot lacks the altitude to successfully recover!
Some Speakers Rhetorically Stall & Even Crash!
Introductions are designed to prevent rhetorical stalls — To prevent taking off too fast into the theme or subject and not giving time for the audience to adjust to where they are going.
Transitions are designed to prevent rhetorical stalls — To prevent sudden movement onto another point and creating confusion as to where we are and what the connection is.
Illustrations / analogies are designed to prevent rhetorical stalls — To prevent too steep of a conceptual-theological climb for the audience and a loss of clarity and understanding of what you are talking about.
Feedback is designed to prevent rhetorical stalls — To prevent a speaker from realizing that the audience is about to crash.
Audience Adaptation is designed to prevent a rhetorical stall — To prevent a speaker from buzzing the audience and then trying to pull up and out of audience excitement or upset he/she just created.
Conclusions are “controlled stalls”** — To let the audience know that we are landing on the Big Idea.
Other Information & Links:
*See the previous article on stalling for further understanding of what the term means. If has nothing to do with whether the engine is running or not. It is not the same meaning as with a car.
** “Controlled stalls” are another whole discussion. A landing also changes the direction of the airflow across the airfoils / wings, and some would say that landing an airplane is a controlled stall at an instant before touch down. “Rhetorically” — some speakers just drop the plane hard onto the runway!
The “angle of attack” is critical and that is why it is always amazing when the aerodynamic industry demonstrates an airplane that has the power to pull up at a dizzying climb off the runway — a “crazy” angle of attack — as seen in this LINK!