Originally Posted by Gjn290
They should really expedite the integration before something terrible happens. What would happen if a drone hit a foreign aircraft on US Soil and it was a government drone? Not good.
The integration is going to involve an exemption for see-and-avoid. There is no suitable technical alternative at this time. There are two possible approaches to see-and-avoid substitute for UAVs...
First off ADS-B and Next-Gen will not solve see-and-avoid for UAVs. They were not designed for that.
1) Enhanced TCAS, possibly based on ADS-B. ADS-B would probably have to be modified to accommodate this. Anyone who has used TCAS knows that it's far from reliable...sometimes it just doesn't "see" other aircraft, probably due to antenna placement. This is OK, since TCAS is a backup to see-and-avoid and ATC separation...but it's not good enough to be a primary defense. A reliable TCAS-like solution would be expensive and would require retrofit on at least 121/135 aircraft and maybe all aircraft. The alphabet groups will not be happy about subsidizing a massive ATC system upgrade just for the convenience of UAV proponents, and presumably they'll prevail.
2) Self-contained sensors within the UAV to give see-and-avoid equivalent capability against any aircraft, even one without a transponder. This probably makes the most sense but would require multiple, expensive (and heavy) sensors on each UAV, probably a combination of electro-optic and radar, capable of scanning large sectors. The UAV crowd will probably fight having to implement a robust solution since if you start piling on a lot of weight it starts to defeat the point of unmanned.
3) Leverage materials and electronics advances to miniaturize and soften UAVs to the point where they can't really hurt a manned airplane (ie nerf-drone). This might eventually work for many, but not all applications.
My guess...rather than requiring #2 up front, the FAA (under congressional pressure) will grant waivers and relaxations to see-and-avoid for UAVs. As they proliferate, they'll take out a few manned airplanes, including perhaps an airliner. The resulting backlash will ground or severely restrict the UAV fleet for several years while they implement #2.