Today’s Illustration: With Great Speed, Comes Lift!

What: Aerodynamic Lift — simplified

  • “Lift” is the force exerted on the wings of an airplane.
  • When the air flows faster across the wing’s top surface than the undersurface of the wing, that difference in airflow creates lift.
  • The airplane is, in a sense, sucked up off the ground by the differing air pressures between the lower surface and the upper surface.
  • With a commercial airplane, the wings’ width is extended during take-off and landing to increase the wings’ surface area of the wings and thus creating greater lift at slower speeds.
  • As the speed of the commercial airplane increases, the extended wing width is retraced.
  • Speed, altitude, and wing design all affect lift.
  • A commercial airplane lifts off the runway when enough lift is created by the airplane’s speed and, therefore, the airflow across the wings.
  • “An Aerodynamic Stall” has nothing to do with the engines of an airplane, but with the loss of lift on the wings. A “stall” means that the loss of lift on the wings has been lost because the proper flow of the air across the wings has been disrupted or lost.
  • Landing an airplane could be described as a “controlled loss of lift” or a “controlled stall.” You are purposefully creating less lift by lowering the forward speed and changing the angle of attack of the airflow across the wings of the airplane in order to drop onto the runway.

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Key Biblical Thoughts:

  • evangelism
  • the battle / the good fight
  • quickly / haste [1]
  • determination
  • power
  • reconciliation
  • missions
  • passion
  • encouragement
  • temptation
  • trials
  • the enemy
  • motivation
  • overcoming
  • commitment
  • discouragement
  • energy
  • strength
  • finished the course / a smooth landing
  • lost lift

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Sermonic Example: There are several distinct ways that one can use illustrative material.

(use whatever you find useful in the above details)

Someone asked this question about fighter jets . . .  “Can a fighter jet lose the power of one of its jet engines and maintain flight?”  The answer is interesting because it speaks to design.  The design of a fighter jet is such that it can fly at great altitudes, with greater speed and mobility because of its wing structure.

Its wings are short from the front leading edge to the back trailing edge, and they are also slopped backward for speed, altitude, and maneuverability.  If a pilot were to lose one of its engines, it would be difficult to maintain flight because of the loss of lift — the loss of the lift that its airplane wings are designed to provide, even at high altitudes.

A lack of speed can cause issues because of the design and, therefore, the loss of lift, but also when it is flying at high altitudes where the air is thinner and results in even more loss of lift.

The fighter pilot faces the possibility of an aerodynamic stall when the speed drops, added to the demand that comes with high altitudes.  With the loss of great speed comes loss of lift.

II Kings 13 is an example of a well-known “fighter pilot,” Elisha.  Elisha was nearing his death and received a hospital visit by the king of Israel, Joash, king over the northern kingdom.  Joash was challenged by Elisah to fight hard against the Syrians.  Don’t let up!  Fight hard against the enemy.

However, Joash lacked the fighting spirit that possessed Elisah and pulled back on the throttle, deciding not to move at full speed ahead — fighter jet speed.  Joash was told that he would lose the lift needed to overcome the enemy when he did that.

With the loss of great speed, comes loss of lift. [2]

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Other Information & Links:

1. Some might believe that speed is not a biblical virtue or a wise method of action.  Such is not the case. Many examples throughout the Bible speak of “haste” and “quickly.”  To lessen one’s speed is to lose lift — i.e. Proverbs 6:3-5

2. Might be a “BigIdea” that is used throughout the message

https://aviation.stackexchange.com/questions/20993/how-does-a-fighter-jet-perform-good-and-quick-maneuvers-with-such-small-wings

https://howthingsfly.si.edu/ask-an-explainer/how-do-jet-fighter-wings-generate-lift-they-are-very-thin

ASK AN EXPLAINER

Q: How do jet fighter wings generate lift since they are very thin?

A: Jet fighter aircraft are very different than typical commercial airplanes, but they still share the basic principles of flying. One of the most important aspects of fighter jets is their ability to go fast. By making the wings thinner, jets are able to move more quickly. One other advantage to thin wings is that they do not have as much stability as thick wings. This way, fighter jets can do tricky maneuvers in the sky.  But even with thinner wings, fighter jets are still able to produce lift by using an airfoil shape and Bernoulli’s Principle.

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