I soloed an airplane on the first day legally possible, my 16th birthday. So let’s step back to a bright summer day in Weatherford OK in 1994.

CFI Jack Sauer, Airplane C-152 N64849, and Student  Pilot Charles O’Neill in 1994

The first stop is not the airport. No, the first step to flying an airplane is sitting in a doctor’s office for a physical exam. When the weight of the paperwork equals the weight of the airplane, the airplane is said to be airworthy. With the medical certificate in hand, I’m off to the airport.

The airplane is a Cessna 152 with registration N64849. Looking at the FAA registration, she is a 1981 model and lives in LA nowadays. My flight instructor was Jack Sauer. I have no idea where he is now. He was initially quite skeptical of training a kid until a pre-preflight walk-around where I started naming aircraft parts and functions. Lesson learned: Know your stuff and doors open.


Afterwords, the traditional shirt-tail-cutting was performed.

Thanks to my parents for finding these long-lost photos.

The first photo is from a small museum.

For more information on why I was there, visit the caselab website.

Navion Roll with Rudder Deflection

The full presentation is available here.

Low Reynolds number flows concern flows with a small ratio of inertial to viscous forces. Laminar flow dominates this flow region. Low Reynolds number flight is the most common (birds, insects…) yet it proves difficult and inefficient in human controlled flight. This paper discusses and shows some characteristics of low Reynolds number flows.

Laminar Separation Bubble: From Reference 5

The short paper is available here.

This project’s objective is to describe and control a DC stepping motor. Qualitative stepper motor theory is presented. An example driver with schematic using the PIC16F876 programmed in C is included.

The mini-project is available here.

This paper will discuss four areas of unsteady helicopter rotor aerodynamics. First, this paper discusses the classical harmonic solutions to rotational aerodynamics and their relationship to the fundamental Theodorsen  solution. Second, modern solution techniques are discussed. Finally, the paper describes wake interactions and their noise production implications.

From: A. R. S. Bramwell, Helicopter Dynamics. New York: John Wiley & Sons, 1976

Unsteady helicopter aerodynamics are complicated. An understanding of the governing physics is possible by isolating simplified systems. Early contributions were based on harmonic analysis. These methods predicted the basic governing fluid physics and warned about blade-wake interactions. Most modern solutions are based on discrete flow representations and computational solutions. These solutions allowed high resolution studies of fluid flow at the expense of physical insight. These discrete flow methods confirmed the blade-wake interaction sensitivities. Blade-wake interactions are shown to create intense and directional disturbances.

The helicopter rotor is a fundamentally unsteady aerodynamic process. Rotor analysis goes from simple 1D shed vorticity models to fully 3D transient turbulent experiments. While the fundamentals of unsteady rotor ?ow are known, an overall theory with a closed form solution is clearly impossible. Further developments in unsteady helicopter aerodynamics will continue as long as the helicopter is a viable transportation vehicle.

The full paper is available here.