Dedicated to lifelong friend, teacher, collaborator, Dr. Andy Bauer Dedicated to my lifelong friend, teacher of PhD Level Aerodynamics, collaborator, Dr. Andy Bauer  | About  | Bio  | Insight  | Download The Books

Betz perfect helical flow
Tapered SHAPE, Pitch, Twist creates it
with Half Teardrop Radial Loading.

Perfect Propellers

Easily Understood 

The book cover shows it all. Click to see.

Click picture to see full size.
The Family of Tapered SHAPE Props
From low Pitch, Adance per rev. to high, creates
Perfect Half Teardrop Radial Blade Loading!
Betz makes it the perfect propeller equivalent of Prandtl's perfect, elliptical Spitfire wing.   Goldstein-Theodorsen 3D math makes it exact.
Perfect Tapered SHAPE, Pitch, Twist  creates  Perfect Half Teardrop Radial Blade Loading ? Perfect Props.
You would not design a wing like this!
Should not design prop that way, either.
Why Tapered Tips? A Rotating Wing Tries Violently to be a Tip Thrust Loss, Tip Vortex Loss Disaster.
Any Wing wants max loading Inboard, Zero at the Tip, Zero tip Lift, or Thrust, to Minimize Tip Vortex Loss.    Basic!
A Rotating Wing: Tip Dynamic Pressure, q, proportional to V2, is a Disaster of Lost Thrust into a Violent Tip Vortex Loss!
Simply, Tapered Tips Counteract the Disaster, Minimize Energy Loss, have Least Torque Demand, get Max Thrust!     Easy!
Simply, The Prop with the Least Loss, Least Torque Demand, Creates the Most Thrust – Tapered Tips Win!  Norris's 8th law.
Click pic for full size
HISTORY: everything we learn here is based on classic Betz logic, 1919, essentially exact Goldstein-Theodorsen math, 1948, Norris & Bauer, 2007.
It's rare genius: Classic Betz exact logic; essentially exact Goldstein-Theodorsen math that teaches us how; Jack Norris's insight.

WhirlWind 200 RV
It's not just theory and math. It works!

A group of RV Pilots just placed an order for 74 Whirlwind 200 RV props, the first exact prop. They get it. The First Exactly Correct, All 6 Way Optimized Perfect Prop, in the History of Flight!

Scarlet Screamer At Reno, in the Formula 1 Gold Race, 14 September 2008, a Cassutt with an extra high pitch race prop left everyone in the dust in the takeoff race to the first pylon. It won second, beating better planes, losing only to the far superior airplane "Endeavor". Race pilots bought a lot of these books at Reno that day.


Big Picture   Efficiency & More


It's actually two books in one, back to back.
Propellers     Propellers

Rare Genius Work by Historic Technical Giants, it took a 10 year World Class Program to get all the brilliance in their 83 year program really correctly understood, and simplified.   We discovered Classic, Perfect Betz prop logic, Goldstein - Theodorsen essentially exact math. But, with no math, the book teaches it all in understandable, incisive insight. We learn the exact logic; the bottom line of 142 years' historic work. We see, through easily understood physical logic, the horse sense of what happens physically:


  • BGT Radial Blade Loading is Perfect.


  • A rotating wing is a thrust loss, tip vortex loss Disaster. It's the core problem that was never really, correctly grasped for 138 years, 1865 to the Wright’s 100th anniversary.   It's the Central Problem in Propeller Design that understanding the Historic Rare Genius Work teaches us.

  • Pulling in and throwing back air - Newton's laws , hugely more massive flow rates than you realized!

  • An airscrew , teaches why a high pitch prop is most efficient, both less induced loss, and profile drag loss.

  • The classic, precise, optimum, minimum induced loss "BGT" prop’s radial blade loading.

  • The ideal family of optimally SHAPED, loaded, pitched, twisted, all 6 way optimized props, minimum Induced, minimum area, precisely placed; thus minimum drag, minimum torque demand, minimum H.P. demand; thus MAX THRUST, MAX efficiency!   



Simply Flying the IAS, Indicated Airspeed that Maximizes IAS vs. Drag , gets you 31.6% more Speed for only 15% more Drag than the Absolute Minimum. But then, Climbing to the Max Possible Altitude holding that IAS, Finally Wide Open, Lean, (never Lean, Low), your Plane and Engine are Perfectly, Optimally Matched, Power Exactly Equal, Matched!


If your plane Tops Out at 12,500 feet, TAS/IAS is 1.21. Now, 1.316 x 1.21 = 1.59. You’re flying 59% faster for only 15% more Drag than the Min. Drag Possible, The Thinking Man’s Way to Fly, The Engine at Low Power, Optimally Leaned, Low Fuel Burn, Optimum TAS, MPG!

All Learned on the Cover, The First Few Pages, Optimum Flight, the Flight Book becomes the Simple, Insightful Pilot’s Aero 101 Course that you could normally never find ! Basic Aero, Engines, all the insight you could never find, everything in One Double Book! It’s the Pro’s Lifetime of Insight, the logic, all purposely “easy enough”, the insightful, understandable, horse sense of what’s happening physically, the kind of insight we can all see through, and understand!

Written by The Technical Director, Mission Control, on the Voyager World Flight, it is the insight, and the level of Insight that you could never normally find. Before this, we never were going to have an explanation of Propellers, and this book nails it all, understandably!
It's all in one combined Double Book, that you could normally never find.

This site and all materials copyright © 2009 Jack Norris.