Building and Testing the Articulating Boom

Building and Testing the Articulating Boom

"Where'd you get the lead screw?"

"Amazon.com, in the aviation section."

A ferry pilot, having a cup of coffee before pulling a 747 from flying storage in Mojave, stares at the contraption on the wingtip of my beleaguered KR2S. We're getting ready for a video flight to show the articulating boom in action, and it's drawn some attention from the usual crowd of pilot-y folk. The story starts a couple of weeks ago, over a sandwich and a coffee at Stoken Donuts.

That Time It Got Quiet

That Time It Got Quiet

The second neutral point flight started out with an uneventful airborne pickup. I was solo in the instrumented KR, and Diane Barney flew chase with Colin Bowman as FTE in the Tiger. Colin was armed with a laptop, AirDAQ receiver, and was making good use of my DSLR. Since these flights are CG-critical, myself and Colin were both paying extra attention to fuel management. Ten minutes into the flight, we had just completed our first sawtooth, and the engine went quiet.

How We Fly the Air Data Boom on Everything

How We Fly the Air Data Boom on Everything

One of the capabilities we've built at Spingarage that I'm most proud of is the ability to show up at a hangar at the crack of dawn and have an air data boom ready to fly on an airplane we've never seen before by the time everyone's done sipping their coffee and checking the weather. I get a lot of questions about how this works, so I wanted to take a minute to explain the two pieces of the puzzle that make this possible.

KR2S Neutral Point Prediction with a Wireless String Potentiometer

KR2S Neutral Point Prediction with a Wireless String Potentiometer

The Mojave Experimental Flyin is always a great place to walk around and bump into people smarter than you, and one of the recurring themes amongst this group of awesome folks was a need for instrumentation of surface positions to complete the AirDAQ architecture as a flight test tool. Diane Barney had taken an interest in the KR2S' "quirky" longitudinal stability, so I got to work on an elevator position string pot and she got to work on a test plan for a neutral point prediction. A couple of days later, I was calibrating the PotDAQ on the KR2S's hstab. It turned out to be a pretty cool piece of hardware. It uses the same temporary attachment scheme as the air data boom, an industrial-grade string potentiometer, and a repurposed air data computer from a Featherweight boom. It's still a little bit bulky, but it provides repeatable measurements of surface position down to about 0.15 degree.