Sunday, August 26, 2018

ADS-B In Upgraded To Dynon SV-ADSB-472

Out with the old and in with the new. Even before the first flight the DOG Aviation RV-12 has been outfitted with Dynon’s SV-ADSB-470 an ADS-B In receiver but for reasons explained a few paragraphs below, I’m upgrading to Dynon’s latest ADS-B In solution …. The SV-ADSB-472 ADS-B In receiver.

For non-aviation readers, ADS-B stands for Automatic Dependent Surveillance—Broadcast. The FAA is requiring that by year 2020 all aircraft flying in Class A, B or C controlled airspace be equipped with ADS-B Out … this means (with few exceptions), that any airspace currently requiring an aircraft to be equipped with a Mode C transponder will now require the aircraft to broadcast an ADS-B Out signal.  This is part of the FAA’s broader plan called NextGen … which will require all aircraft flying in the aforementioned airspaces to periodically send an ADS-B Out broadcast containing information about the aircraft, such as identification, current GPS position, altitude, and velocity. It is said that NextGen will allow for more aircraft to be in “the system” because radar will not be needed to see the aircraft … plus, air traffic controllers will know the exact altitude, speed and GPS location of aircraft which should allow tighter spacing of aircraft than is currently possible with a ground based radar air traffic control system.

Of course, when the NextGen year 2020 mandate was announced many years ago, pilots and pilot advocacy  groups howled (and rightfully so) because the ADS-B Out mandate will cost aircraft owners thousands of dollars to retrofit their aircraft to meet the year 2020 requirement … yet the aircraft owners really got nothing in return. So to sweeten the bitter pill, it was decided the FAA would transmit weather radar (which until recently was a third party paid for service from companies such as XM satellite) and other useful pilot information. The new transmission is called FIS-B (flight information service broadcast) and is transmitted from ground stations to the aircraft and received using an ADS-B In receiver. The ADS-B In receiver also receives the ADS-B Out position transmissions from other aircraft in the vicinity which can subsequently be displayed on a screen in the aircraft.

The FIS-B signal transmitted from ground stations allows an ADS-B In equipped aircraft to receive NEXRAD (near real-time weather radar) information which can be overlaid onto a moving map. In addition, flight service information including METARs (aviation weather reports), TAF’s (terminal area forecasts), TFRs (temporary flight restrictions), PIREP (pilot in-flight reports), winds aloft and much more can be received. All great stuff to have available inside the cockpit … especially during cross country trips.

One nice thing about having a Dynon SkyView is if the aircraft is also equipped with Dynon’s ADS-B In receiver, the SkyView can not only display the FSI-B information mentioned above but it also displays information about other aircraft in the vicinity on the moving map without the need for additional displays in the cockpit. The displayed information can include the aircraft identification, position information, altitude above or below your aircraft (also shows if the target is ascending or descending) and a trend vector showing where the target aircraft will be in 60 seconds based on its current trajectory through the air. All very cool stuff!  The ADS-B In information can be received directly from other aircraft in the vicinity via transmissions between the aircraft or from ground stations. The FAA has adopted two frequency standards for ADS-B out transmissions …. 978 MHz UAT (Universal Access Transmitter) and 1090 MHz called 1090ES (Extended Squitter). The 978 MHz UAT is the FAA’s preferred ADS-B Out frequency for aircraft primarily flown below 18,000 feet and 1090ES is primarily for aircraft flown above 18,000 feet (primarily commercial aircraft).

The reason for removing the SV-ADSB-470 ADS-B In receiver initially installed in the DOG Aviation RV-12 is because it only receives one frequency (978 MHz) so aircraft broadcasting on the higher 1090 MHz frequency may not be displayed on the Dynon SkyView unless relayed by a ground station. Last year, Dynon announced the new SV-ADSB-742 ADS-B In receiver which receives both frequencies … now all aircraft equipped with ADS-B Out whether using 978 or 1090 MHz will be seen on the SkyView map screen.

To Dynon’s credit, Dynon offered SkyView owners who originally purchased the single frequency SV-ADSB-470 an opportunity to exchange their ADSB-470 box for the new SV-ADSB-472 dual frequency ADS-B In receiver at a fraction of the cost of the 472. To me that was a no brainer … so I signed up for the exchange program.

It amazes me how small the new dual band SV-ADSB-472 receiver is compared to the original SV-ADSB-470 box. The 470 spanned the entire area above the Garmin radio as can be seen in the photo below. (This confirms a long held belief of mine that one has to just accept the fact that when purchasing electronic items, they are pretty much obsolete the day you by them because technology is moving at such a rapid rate).
The Dynon SV-ADSB-470 single frequency (978 MHz) ADS-B In UAT receiver. Note how big this box is … it takes up the entire area above the Garmin GTR 200 radio rack.

Instillation of the new SV-ADSB-472 was quite easy … except for the time consuming task of removing all the screws necessary to gain access to the backside of the instrument panel. Fortunately, the new dual band SV-ADSB-472 receiver uses the same DB connector (which is almost half as big as the box) and antenna connection. However, because the 472 is SO MUCH SMALLER than the 470 box, it requires the addition of a mounting plate to span the top of the Garmin GTR 200 radio. The same mounting locations the 470 screwed into are used to mount the adapter plate. The new mounting plate can be ordered directly from Van’s. As one can see from the photos below, the connections to the SV-ADSB-472 are on the right and left ends ... whereas the connections to the original SV-ADSB-470 were along the front edge of the box. This almost created a problem with the antenna cable, but fortunately after rerouting the cable a little, there was just enough slack to attach the antenna cable to the 472 box.
Completed instillation of Dynon’s SV-ADSB-472 ADS-B In receiver. Note how much of the mounting plate is exposed … the old 470 box covered this entire area. By comparison, the new 472 box is really small. My finger is pointing to the DB connector which is almost half as big as the new 472 box.
Another view of the completed SV-ADSB-472 instillation showing how small this box is compared to the first photo posted above of the old 470 box which completely covers the top of the Garmin GTR 200 radio.

After installing the new SV-ADSB-472 receiver, a configuration change needs to be made to the SkyView’s serial port the 472 box is connected to. First verify the SkyView’s software version … the SV-ADSB-742 receiver REQUIRES the software to be Version 15.1 or newer to support the 472 box. If that is OK, the next step is to configure the serial port the 472 is wired to … this is done by entering the Setup Menu by pressing and holding down buttons 7&8 on the SkyView and then navigating to the serial port the 472 is wired to (it will be the same serial port the old 470 was wired to if upgrading as I was). SETUP MENU > SYSTEM SETUP > SERIAL PORT SETUP > SERIAL PORT x SETUP (the serial port the SV-ADSB-472 is wired to) > SERIAL IN DEVICE > SV-ADSB-472 > ACCEPT (button).

At this point the SV-ADSB-472 receiver should be configured properly and the serial port it is wired to should be showing transmit and receive packets incrementing as the SkyView and 472 box talk back and forth … if so, tap yourself on the back for a job well done.