It seems like you're asking about the plane principle, but it's not a widely recognized scientific or mathematical principle. It's possible you're thinking of something else.

Here's what I can tell you:

* Planes in Geometry: In geometry, a plane is a flat, two-dimensional surface that extends infinitely in all directions. There are no "plane principles" in the context of geometric planes. They are simply fundamental geometric concepts.

* Planes in Aviation: Planes are commonly used in aviation, but they're not related to any "plane principles." The principles that govern flight are based on aerodynamics, including lift, drag, thrust, and weight.

* Other Possibilities: Perhaps you're thinking of a different term that sounds like "plane principle"? Could you provide more context or a specific example?

To help me understand, please tell me:

* Where did you encounter this term? (e.g., a book, a lecture, a website)

* What were the concepts being discussed?

* What did you understand the "plane principle" to mean?

With more information, I can help you clarify what you're asking about.