The FAA has mandated Automatic Dependent Surveillance-Broadcast (ADS-B) Out capability for flights after January 1, 2020, in airspace where a transponder is required today. And although the ADS-B final rule was published in May 2010—and right now, let’s call it 12 months to go before January 2—aircraft owners still have a lot of questions. Learn more here.
Many aircraft are going to be equipped with required ADS-B equipment by the 2020 deadline. However, many will not, especially those residing on the many For Sale lists of various publications and websites. After the 2020 deadline, if you purchase one of these listed planes that is not equipped, what will the FAA require the purchaser to do prior to moving the aircraft if it is either purchased within the Mode C veil or being moved to a field that is within the veil.
(g) Requests for ATC authorized deviations from the requirements of this section must be made to the ATC facility having jurisdiction over the concerned airspace within the time periods specified as follows:
(2) For operation of an aircraft that is not equipped with ADS-B Out, the request must be made at least 1 hour before the proposed operation.
Pilot A has ADS-B out and ADS-B in... and is flying down Valley A between mountains.
Pilot B has ADS-B out and ADS-B in... and is flying down Valley B between mountains.
Just ahead for both pilots, Valley A and Valley B meet/merge and become Valley C.
Because they are in valleys between rural mountains, no line-of-sight communications towers of any kind exist on the mountains surrounding Valley A or Valley B.
My two questions are:
#1: Will Pilot A and Pilot B be aware of each other before they are line-of-sight to each other?
#2: Will Pilot A and Pilot B be aware of each other after they become line-of-sight to each other?
If ADS-B signals are sent-to and received-from Iridium or some other satellite network, then Pilot A and Pilot B would always be aware of each other no matter the nature of the topography.
If ADS-B signals are not sent-to and received-from Iridium or some other satellite network, but ADS-B equipment can receive and decode ADS-B signals from other aircraft via direct line-of-sight signals, then the moment Pilot A and Pilot B were line-of-sight to each other, they would be notified of each other.
If ADS-B signals are ONLY relayed by towers but cannot function based upon direct line-of-sight signals from other ADS-B out equipped airplanes, then Pilot A and Pilot B will NEVER be made aware of each other by the ADS-B system.
It seems obvious to me that ADS-B should function via communication with a satellite network.
But if ADS-B does not work that way, but instead communicates via ground towers, then ADS-B should AT LEAST be capable of direct line-of-sight communication with other nearby aircraft. After all, those are the aircraft a pilot might soon run into!
So... HOW DOES ADS-B WORK ?????
So... HOW DOES ADS-B WORK ?????
Short and oversimplified answer is that ADS-B equipped aircraft do communicate directly with each other in addition to ATC and ADS-B ground stations, so your valley flyers should be made aware of each other by the ADS-B system.
I read recently that Canada is proposing a satellite based ADS-B standard, which would require antenna diversity (antennas on the top and bottom of the aircraft) and compatible ADS-B equipment, which is a significant burden for aircraft that comply with the current ADS-B standard in the United States.