In looking more closely, it appears that all of the SFRA is within the IAD-DCA-BWI mode C veil. However, in reading the training material it appears that there is no exemption for non transponder aircraft within the SFRA, but I’m not sure if that’s a rule or just a limitation on the training material.
https://www.faasafety.gov/files/gslac/courses/content/55/707/SFRA%20Course%20Notes%20%20111130.pdf
Interestingly, part 91 is prohibited in the FRZ, though I suppose that makes some sense. (OTOH, they have the Hudson River VFR transit, which is hardly farther from critical things.)
I’m not familiar with the SFRA having never flown myself within it, or near it, but FAA Mode C transponder regulations are here. The ADS-B Out regs will be exactly the same in terms of airspace applicability and exemptions, starting in 2020. Note that the non-transponder and non-ADS-B Out exemption applies only within the veils, within Class E or D airspace, and not within the actual Class B airspace at the core of the veils. It also applies only to aircraft never equipped with an engine driven electrical system. That is a few planes, but not many planes.
eddsPeter wrote:
To get ADS-B out you need to upgrade the GTX330 transponder to the GTX330ES. No need for the GTX345.
That would be assuming that you already have a GTX330 installed, which is not the case for my client.
Peter wrote:
His other antennae are really close together and really close to the big Lynx one
In fact, his antennae installation ignores the STC requirements :
3b. The GPS antenna should be mounted no closer than two feet from any antennas emitting more than 25 watts of power. An aircraft EMC check can verify the degradation of GPS in the presence of interference signals.
3c. To minimize the effects of shadowing at 5° elevation angles, the GPS antenna should be mounted no closer than 6 inches (edge to edge) from other antennas, including passive antennas such as another GPS antenna or XM antenna.
4. To maintain a constant gain pattern and limit degradation by the windscreen, avoid mounting the antenna closer than 3 inches from the windscreen.
5. For multiple GPS installations, the antennas should not be mounted in a straight line from the front to the rear of the fuselage. Also varying the mounting location will help minimize any aircraft shading by the wings or tail section (in a particular azimuth, when one antenna is blocked the other antenna may have a clear view
Interesting – if you mount two antennas they will always be in a straight line … from front to rear doesn‘t make sense either especially for a GPS antenna
Sir_Percy wrote:
Interesting – if you mount two antennas they will always be in a straight line … from front to rear doesn‘t make sense either especially for a GPS antenna
What it means is that the two antennae should not be mounted in a straight line parallell to the front-to-rear centreline of the fuselage. I don’t have a clue as to why, but the requirement as such makes perfect sense.
Every TCAS installer told me privately that the STC cannot ever be complied with in this area.
I understood what they tried to say but
In systems where you want to determine the orientation without movement (ususally precise positioning systems)you do exactly that – mount them in a line parallel to the longitudial axis.
So for what reason/function does this requirement makes sende
Sir_Percy wrote:
if you mount two antennas they will always be in a straight line …
