As a testbed and simulation verification unit for the ICARUS, the Falcon is intended to be a high-speed, high data rate flight logging aircraft, to build accurate flight dynamics model for flying wing aircraft.
Dissatisfied with the DATCOM & Simulink predictions of flight performance of flying wing aircraft, I decided to make the Falcon to both (A) Get very good at flying RC aircraft (B) Develop a flight dynamics prediction model for flying wing aircraft.
The airframe is designed by FliteTest, the FT Arrow design. I made a blunt nose modification in order to accommodate a larger payload volume.
Initially, I filled the avionics bay with an Arduino Mega 2560 and MPU6050 AHRS unit, as well as a receiver. The battery would sit behind the Mega.
As a keen eye may notice, there is a second MCU there as well. In addition to the Arduino Mega 2560, it was quickly determined that data logging could not happen on the same MCU as the primary flight controller. I shelled out for the beautiful Adafruit Feather Adalogger M0 Cortex. I also put a bi-directional level shifter between the boards so that they could communicate on Serial from 5V logic to 3.3V logic.
At this point, lots of really great flight computer code was developed, drawing lots of inspiration from the Apollo Guidance Computer (AGC) as documented by the book Digital Apollo by David Mindell.
Program alarms, fast control loops, clear hierarchies, etc were all put into the Mega 2560. All in all, the code was small enough to be run on an Arduino Uno after all!
Just as I finished this project, another project came… Teaching a “drones” summer camp for kids at Learn Beyond The Book.
I put the plane’s first flight off for after the camps!
After the camps
Well, shortly after the camps concluded it was time to pack for a 2 month trip to the other side of the globe and back. No time for first flight!
After the trip
Upon returning to California, I decided to attempt first flight!
I turned the entire aircraft into a hardware-in-the-loop simulator tied into Kerbal Space Program, in order to get very comfortable at flying RC controls prior to first flight.
Then, came the maiden.
All systems performed flawlessly! For the first 1.5 seconds… The biggest problem identified was that the aircraft was seriously nose heavy and too heavy in general. The Arduino Mega and SD Card Shield (used to mount the MPU6050) were adding too much nose weight.
A redesign incorporating the beautiful Adafruit Metro Mini 5V was made, and tested. The flight program takes about 80% of flash and runs just as smoothly as ever!
The best part of all of this, is that the aircraft is now perfectly within center of mass design limits, and will likely fly very stably!
The re-maiden is an event currently in purgatory. The aircraft is ready, the pilot (me) is ready, but the focus of my life’s work has changed direction for the near term.
On that big trip, I had important realizations about the future of aircraft, and I am far more excited about chasing the fruition of those dreams than chasing a successful first flight of the Falcon & ICARUS.
So, this plane is on hold.
I am quite convinced however, that it will find its way back into my focus soon, and that the Falcon will fly again. Then, with that confidence of operation, the ICARUS will attempt its first flight toward the sun.
Thanks for reading and STAY TUNED on the blog!
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