Hackaday Prize Entry: Modular Instrumentation For Aircraft

Parts, tools, and components for aviation and aerospace are sold in ‘Aviation Monetary Units’ (AMU). Right now, the conversion factor from USD to AMU is about 1000 to 1. This stuff is expensive, but there is a small portion of the flying community that prides itself on not breaking the bank every time something needs to be replaced. Theses are often the microlight, ultralight, and experimental aircraft enthusiasts. Steam gauges are becoming obsolete and expensive to repair, and you’re not going to throw a 15 AMU Garmin G500 in an ultralight that only costs 10 AMU.

To solve this problem, [Rene] is turning to sensors, displays, and microcontrollers that are cheap and readily available to build modular aviation instruments.

As with all aviation gear, the first question that springs to mind is, ‘what will the FAA think about this?’. [Rene] is in South Africa, so the answer is, ‘nothing’. If a few American pilots decide to build one of these, that’ll fly too; these are instruments designed for non-type-certified aircraft. That’s not to say there are no rules for what goes into these aircraft, but the paperwork is much easier.

Right now, the design goals for [Rene]’s instruments is under 0.1 AMU per module, robust, RF shielded, with engine monitoring, fuel management, heading, air and ground speed, altitude, attitude, and all the other gauges that make flying easy. He’s using a CAN bus for all of these modules, and in the process slowly dragging the state of the art of ultralight aviation into the 1990s. It’s fantastic work, and we can’t wait to see some of these modules in the air.

18 thoughts on “Hackaday Prize Entry: Modular Instrumentation For Aircraft

    1. It has wheels though, so it’s a vehicle. Mobile homes have wheels, they too are vehicles, right?

      What about boats? They don’t really have wheels unless you include wheels roped to the side of the vessel to mitigate damage when docking. Are they homes or vehicles.

      US Supreme Court case of LOZMAN v. CITY OF RIVIERA BEACH, FLORIDA
      https://www.supremecourt.gov/opinions/12pdf/11-626_p8k0.pdf

      It can be harder to accurately define than you might expect.

      1. How do you define flight though? The space shuttle isn’t really a plane so much as a means of arriving to the earth in a glider like vehicle. Was the shuttle an aircraft? Is a drone an aircraft? Is a flying insect an aircraft?

          1. No and No. My point was that the legal definition and what you would think of as common sense don’t always coincide. Is a boat always a boat, even when it becomes larger than a house? Is a drone the same as an aircraft? What about a drone that was big enough to fly people? It’s the same thing that we are dealing with now with self driving cars. It disrupts the existing legal framework due to being novel and innovative and never before encountered. That’s also in part why so much buzz surrounded 3d printing of guns.

            Making guns used to be an extremely skillful endeavor and that shifted, albeit somewhat slightly, with the advent of more modern manufacturing techniques that made gun fabrication a bit easier. In practice, not much changed really as the hype far exceeded the reality but that was due in part to several different factors, including intentional marketing buzz.

        1. Flight is action of a “body” moving through air. The movement can be powered or not powered, essentially a dandelion flower moving through air is flying.

          A Space shuttle isn’t an aircraft it is a spacecraft reason is the medium through which it is intended to operate in.

          A drone is an aircraft

          A balloon is an aircraft

          An insect isn’t one because aircraft relates to machines

          1. The space shuttle has to travel through several layers of atmosphere to access “space” (low Earth orbit) though. Is it an aircraft then and then at a certain point it becomes a spacecraft? Is it both at the same time once it reaches a certain point?

            What about satellites? There is still air in low Earth orbit, just not much of it. When the shuttle is traveling through the atmosphere as it is landing, it isn’t flying then? It mostly just falls to Earth in a fairly poor aerodynamic manner to be honest.

            How much or how little of a machine can a biological device become and still constitute it being a machine and therefore aircraft? Is a person with a pacemaker enough of a machine to become an aircraft if they jumped out of a plane in a parachute or strapped miniature jet engines to themselves?

            Is a rock thrown out of a plane considered to be flying or falling? What if it has a parachute?

            What if it is a satellite falling to Earth? Is that an aircraft as well?

            What if a person attaches jet engines to themselves and wears a wingsuit? They are, to a degree, incorporating technology and machines to their body. Is the hardware an aircraft and the person still a person?

            My point is that it isn’t quite as easy to draw black and white lines is all.

          1. The space shuttle basically falls to Earth in a manner that basically barely avoids it crashing straight down. It “lands” (falls) at over 10,000 ft per minute. It works, barely but it’s not really what you traditionally would prefer.

            Here’s 1161 pages of how to operate the space shuttle:
            http://www.nasa.gov/centers/johnson/pdf/390651main_shuttle_crew_operations_manual.pdf

            What’s interesting is how the landing gear worked. It didn’t allow for much time between “put gear down” and “we are landing RIGHT NOW” and landing gear not deploying wasn’t an option given how fast it was still going when it landed.

            “Because the shuttle was a “glider” (a generous use of that term) at landing, with no chance of going around, the gear absolutely must work on the first try. A shuttle belly landing would have ended very bad due to its high speed and high angle of attack. In order to assure the gear would extend, there were several redundant systems in place:

            The doors had a bungee-assist system which exerted 2000 pounds of force (~9 kN) on the nose wheel doors, and 5000 pounds (~22 kN) on each of the main wheel doors.
            The nose wheel had a pyro-assist system which fired every time the gear was deployed, and helped assure it would lock into place.
            The gear is normally deployed through a combination of “springs, hydraulic actuators, aerodynamic forces, and gravity.”
            However, if all else fails, and the gear does not begin to move within 1 second of issuing the command, a pyrotechnic initiator cuts the locks and forces the gear down.

            So they were pretty confident it was going to work.”

            “The shuttle was designed with a low L/D ratio (~ 1) because during the descent the spacecraft must be slowed from about 17,300 mph to about 250 mph at landing.”

            “The orbiter’s maximum glide ratio/lift-to-drag ratio varies considerably with speed, ranging from 1:1 at hypersonic speeds, 2:1 at supersonic speeds and reaching 4.5:1 at subsonic speeds during approach and landing.”

          2. During a considerable part of it’s “glide” slope is descends faster then what’s considered the normal for skydivers during freefall :D

            There is a sub-sonic trainer plane for the Shuttle (a modified bizjet-like plane), it simulates it’s aerodynamic characteristics during glide slope by using full reverse thrust…

  1. Excellent. Next challenge: do the same for marine-grade instrumentation and hardware, also measured in kilobuck units. That’s why it’s called a BOAT: Break Out Another Thousand.

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