ADS-B out for S-LSA
Posted: Sun Aug 10, 2014 4:48 pm
There seems to be quite a lot of confusion over how to equip an S-LSA for ADS-B Out so I thought I'd take a few minutes and outline what the regulations state (or at least my interpretation of them). For background on ADS-B there are a lot of great sites with Garmin's ADS-B Academy being a good starting point and the FAA itself: http://www.faa.gov/nextgen/implementati ... /adsb/faq/.
There are two methods to comply with the 2020 ADS-B out directive: TSO-C154c (Universal Access Transceiver or UAT) and TSO-C166b (1090ES). UAT is only supported in the US so if you want to go international you'll need to with 1090ES. 1090ES is based on the current Mode S Class 1 transponder paradigm. This is why you can buy an upgrade to a Garmin 330 and be compliant with 1090ES transmission standards. Trig has several compliant models and Dynon has their SV-XPNDR-261.
UAT is a new frequency band and requires a new, standalone ADS-B transmitter. It will have it's own squawk code that will need to be sync'ed with the Mode C transponder or have a common controller for setting the squawk code. UAT is also the method for getting ADS-B In (Traffic and weather). Freeflight, Navworx and Garmin all have UAT solutions.
Now, just because you have a TSO-C154c or TSO-C166b certified ADS-B transmitter does not mean you meet the 2020 mandate. You also need a TSO-C145 GPS position source (or a TSO-C146 approach certified navigation system). It is possible to use a non-certified GPS position before 2020 and enjoy the benefits of ADS-B, though.
For details about the transmission streams and data requirements for all the ADS-B related TSOs you may enjoy reading the 670 page RTCA DO-282B document. Going through this will give you an idea why Garmin has stated the 39x/49x/69x/79x will NEVER be compliant. FAR 91.227 has a pretty good high-level description of key data fields as well.
There has been debate as to whether a portable system can be used to satisfy the mandate. Short answer is 'yes' although the unit ceases to become a portable once it complies with the TSO since the TSO must contain appropriate installation instructions such that the performance is guaranteed to compliant.
We're still not done for an S-LSA. The airplane manufacturer must also approve the system. This would most likely be by a fleet-wide Service Directive or Notification although each individual could ask for a Letter of Authorization (LOA) for their favorite ADS-B solution and I'm sure the manufacturer would be willing to accept your solution for a fee.
You can circumvent the Service Directive/Notification/LOA route if you take your S-LSA to E-LSA although the TSO'ed equipment is required as per FAR 91.225.
There are two methods to comply with the 2020 ADS-B out directive: TSO-C154c (Universal Access Transceiver or UAT) and TSO-C166b (1090ES). UAT is only supported in the US so if you want to go international you'll need to with 1090ES. 1090ES is based on the current Mode S Class 1 transponder paradigm. This is why you can buy an upgrade to a Garmin 330 and be compliant with 1090ES transmission standards. Trig has several compliant models and Dynon has their SV-XPNDR-261.
UAT is a new frequency band and requires a new, standalone ADS-B transmitter. It will have it's own squawk code that will need to be sync'ed with the Mode C transponder or have a common controller for setting the squawk code. UAT is also the method for getting ADS-B In (Traffic and weather). Freeflight, Navworx and Garmin all have UAT solutions.
Now, just because you have a TSO-C154c or TSO-C166b certified ADS-B transmitter does not mean you meet the 2020 mandate. You also need a TSO-C145 GPS position source (or a TSO-C146 approach certified navigation system). It is possible to use a non-certified GPS position before 2020 and enjoy the benefits of ADS-B, though.
For details about the transmission streams and data requirements for all the ADS-B related TSOs you may enjoy reading the 670 page RTCA DO-282B document. Going through this will give you an idea why Garmin has stated the 39x/49x/69x/79x will NEVER be compliant. FAR 91.227 has a pretty good high-level description of key data fields as well.
There has been debate as to whether a portable system can be used to satisfy the mandate. Short answer is 'yes' although the unit ceases to become a portable once it complies with the TSO since the TSO must contain appropriate installation instructions such that the performance is guaranteed to compliant.
We're still not done for an S-LSA. The airplane manufacturer must also approve the system. This would most likely be by a fleet-wide Service Directive or Notification although each individual could ask for a Letter of Authorization (LOA) for their favorite ADS-B solution and I'm sure the manufacturer would be willing to accept your solution for a fee.
You can circumvent the Service Directive/Notification/LOA route if you take your S-LSA to E-LSA although the TSO'ed equipment is required as per FAR 91.225.