On Oct 28, 1:40*pm, "Wayne Paul" wrote:
"Darryl Ramm" wrote in ...
On Oct 28, 8:47 am, Andy wrote:

Just to give a flavor ADS-B data-out systems as mandated for 2020 in
the USA for power aircraft (basically where a transponder is required
today) will put out the following data

Aircraft ICAO ID (can be made anonymous for a UAT on VFR flight)
Aircraft callsign/flight number (not required for VFR flight)
Time of applicability
GPS Lattitude
GPS Longitude
GPS altitude
Airborne/on-surface status
Northbound ground velocity component while airborne (from GPS)
Eastbound ground velocity component while airborne (from GPS)
Heading while on the surface
Ground speed while on the surface
Pressure altitude
Vertical rate (may be pressure or GPS based)
GPS uncertainty/integrity (which needs information form a fancy TSO-
C145 class WAAS GPS)
Ident (equivalent to transponder ident/SPI)
Distress/Emergency status
ADS-B data-in/display capability
TCAS equipage/status

This is a simplified list and there is various other status/validity
data as well. There is also the concept in ADS-B messages of an
estimated position, and even estimated velocity. But AFAIK this is not
intended for fancy manoeuvrings predictions - it is more intended to
allow different parts of the ADS-B infrastructure to project position
or velocity updated to a single time of applicability. There is space
for future expansion and as an example there is long-term work
underway to look at an ADS-B based replacement for TCAS that could
well utilize extra data transmission than that above, but think well
post 2020 for this to actually happen. My brain hurts enough thinking
about ADS-B as is.

---

BTW my suspicion is given that the FAA currently requires a STC for
any installation for ADS-B data out that it is currently not possible
to install any ADS-B data-out system in the USA in any certified
aircraft (including gliders) that only meets a subset of the 2020
mandate requirements (ie. does not include all the stuff above). Which
I expect the FAA would also require fully TSO-C154c/DO-282B (UAT) TSO-
C166b/DO-260B (1090ES) and with the corresponding TSO-C145 level GPS.
Experimental aircraft are another question since an STC cannot apply
to them. This STC restriction hopefully is short-term as its is going
to have a chilling effect on ADS-B data-out adoption in general
aviation and gliders. Besides some more complex issues you can start
to see even simple installation concerns that are probably causing
this current STC requirement, such as squat switch/or other on-ground
detection, needs to have a single squawk code and ident button across
any installed transponder(s) and ADS-B data-out devices, ability to
transmit a distress/emergency code, ability to turn off the ADS-B
transmissions if requested, etc.

Darryl

The following is not directed at any individual, it is simply an observation.

Even the old Garmin 12XL provides a lot more information in it's NMEA sentences the most of us realize. *It is data output sentences are fully compliant with NMEA 0183 ver 2.0. *The following link give an example of the data provided by "GPS engines" to software developer thus minimizing the amount of calculation required in display devices.http://www8.garmin.com/support/pdf/NMEA_0183.pdf

As I watch these PowerFLARM discussion it is apparent that many assume that things provided by the GPS must be created by the FLARM software.

Let us accept the fact that the PowerFLARM is just an upgrade of previous units that have been proven effective in increasing glider flight safety.

Respectfully,
Wayne

There have been several comment regarding the need for an STC to
install an ADS-B system in a certified aircraft.

This is not unlike the original situation with the installation of IFR
certified GPS systems, in the early 1990s. I was involved in several
installations and most of the concerns were about the placement of
antenna and the effect of spurious signals on navigation.

Today if you get an IFR GPS installed in an aircraft the manufacturer
has a detailed description of antenna placement, cable routing and
possible interaction. This data was collected during the earlier STC
period and as experience with more installations was gained, the FAA
changed the requirements from an STC to a 337, if installed in
compliance with the manufacturer's instructions.

I expect that the STC requirements for the ADS-B will follow the same
path over time.

Mike