Cub wrote:I think there is plenty of evidence from the Flight Information Display (FID) trials that a CAP 1391 device is also acceptable for the ground based, short range detection required to enhance the traffic information provision by a suitably qualified FISO or A/G operator.
So not airspace?
Someone in the past suggested ADS-B TMZs - so presumably not suitable for something like that? What about drone TDAs?
Last I heard, the specification for FID hadn't been finalised? Is any of that public yet?
So should we expect all / some / most CAP 1391 devices to be detectable in all directions at 5 nm? I just remember Ian's much talked about
flight test, with various blanking issues, across various systems, some at short distances ("within a few miles"). That doesn't prove anything - but shows there could be issues, even at short range.
I assume someone has walked around an aircraft on the ground, with an SE2 mounted, showing no dead spots using a detector (or stood a few km line of sight of an aircraft on the ground and slowly turned the aircraft round)? At least that could give confidence about all round short range protection in the horizontal plane, of at least one aircraft? A bit more difficult to do that on the other planes, unless you can crane your aircraft so that it sits vertically (etc) so you can check no blind spots underneath at close range. You might say that aircraft would normally move relative to one another, so checking in a single direction isn't required - but that is precisely when a MAC occurs - when two aircraft stay at a constant bearing to each other.