Avionics

Ideas to reduce overall cost of ownership for aircraft.

Moderator: John Nicol

Post Reply
jimgaas
Posts: 5
Joined: 15 Jul 2016, 09:30

Avionics

Post by jimgaas »

I have played with small computers like the Raspberry Pi and the arduino. I looked at GPS chips and I was amazed at how easy they are to operate. You simply attach power to it, an antenna, and ouput comes out in the form of NMEA sentences. It is simply a matter of parsing these sentences with a computer and doing the necessary calculations. More on this later. These chips vary in their quality, performance, refresh rates, etc. The point here is that a GPS navigation device should not be build around these chips. These chips should be completely separate and provide input to a computer for navigation. These chips cost about $20-$60, which I think is very nominal. By keeping these parts separate, new chips can replace old chips or malfunctioning chips very easily, cheaply and quickly. In addition, with the price of these chips so low, it would be very feasible to have several chips that cross reference one another or increase navigational performance. The Europeans and the Chinese are installing their own satellite constellations and chips on the market now will not access these valuable resources. New chips will. So by keeping these chips separate, the chips can be upgraded quickly without junking an entire radio that is built around a cheap chip. You can reference sparkfun.com and search on GPS chips to view these chips.

In addition, a relatively recent discovery is that chips meant to receive television signals have been discovered to receive any radio signal from roughly 25 Mhz to 2Ghz. The implications of this are huge since these chips are also very cheap costing about $20. They are referred to rtl_sdr dongles. A brilliant programmer has built an ads-b receiver with a Raspberry Pi and rtl_sdr dongles receiving 978 and 1090 transponder transmissions. The project is called "Stratux." I have built one of these using a Raspberry Pi 3 which has built in wifi. Using two rtl_sdr dongles and a GPS chip, I can wifi my GPS position to a tablet in my lap. Normally I lose GPS coverage since the tablet sits low in the plane and can't see the satellites. By placing the GPS chip and the antennas for the rtl_sdr dongles on the dash, I get continuous GPS coverage, 1090 reception and 978 reception which gives me nexrad weather, metars, winds aloft, pireps and 978 traffic all for about $100 for the hardware. Chris Young, the programmer, has open sourced the software.

It works with another brilliant and valuable contribution to aviation called Avare. This in completely free software that runs on any android device. It can be downloaded from the google play store. It uses the built in GPS chip in your phone or tablet and provides you with completely free FAA charts for navigation, a moving map, TFRs, etc. All this goes to show that everything in avionics except the actual transmitter can be put together very cheaply.

We all know that the avionics in a plane is probably the most significant cost of a plane short of the plane itself and can even approach the cost of the plane if bought retail and TSO'd. The FAA, EAA and Dynon are working together under the new rewrite of part 23 of the CFR's to allow production planes to use the fantastic avionics that have been available to experimental planes for ages. It makes no sense that non TSO'd avionics are allowed in experimentals but not production planes since it would seem that the lives of the pilots and the families of pilots flying experimental are not considered to be of any concern to the FAA. Of course that is not the case and these devices are worthy and time tested and should be allowed in production planes. That is only just now starting to happen.

One last note: Indicators should not exist. For example, a $1000 to $X,000 VOR indicator or a better example, an electro mechanical HSI that can cost 10's of thousands of dollars, should be rendered on a computer screen, ie a glass panel. Now your cost of an HSI is a tablet screen, input device (GPS chip) and software (open sourced?). The avionics in a plane could and should cost almost nothing. The costs are huge due in large part to the FAA requirements regarding TSO's which are essentially torture tests for avionics. You guys in the experimental market have been blessed with exemption from these very costly mandates by the FAA. The same goes for EFIS systems which can replace heavy and expensive electromechanical gyros with chips. Look at the Dynon website and check out the D10A and D100. Both are now approved for production planes. I hope production planes can be made safer with the technology you have enjoyed for a very long time by letting this trend continue.

Sorry about the long rant!
User avatar
John Nicol
Posts: 596
Joined: 23 Nov 2011, 12:17
Contact:

Re: Avionics

Post by John Nicol »

Hi Jim,

We are on the same wavelength and the team have been working on an open source EFIS and avionics for a while now. If you check out the Open Source Avionics forum area you will see what we have been up to. Particularly with the EFIS and the use of single board computers such as the Raspberry Pi and arduino micro-controllers. I have a Stratux as well that I purchased from the Kickstarter campaign and I have built one from parts gathered from various places. I completely agree with you on the cost and safety implications raised with the new technology.

Phil is working on a homebuilt project now and has indicated that he will put as much open source hardware in the panel as possible. I will do the same as soon as I can! There is no reason why we cannot have a very functional and very cool glass cockpit for under $1000, if not less (including sensors!).

Regards,
John
-----
John Nicol
Founder, MakerPlane
Post Reply