Jason Bowman

I think we are going to need ADS-B sooner than is believed. Has any planning been done to possibly accelerate the move for some types of aircraft and airspace? I don't see how ADS-B Out without ADS-B In solves or help alleviate some of the problems discussed. An ADS-B Out only aircraft still relies heavily on ATC because they can not self-separate. How does an aircraft that can not self- separate operate in an environment with aircraft that can? A controller may instruct one thing to the Out only aircraft but the self-separators may be already doing something else that may conflict with that instruction. I think having two different data links may prove to be a bad idea. There may be performance issues as information flows from one to the other, and maintenance costs for the ground equipment may prove to be expensive because two systems are being maintained. I wonder if the current datalinks have the bandwidth for future growth. Have requirements for additional spirals of ADS-B been discussed? Are the system, protocols, etc. easily upgradeable? I wonder if the requirement for antenna diversity is the FAA's rudder swinging hard over on ensuring a good datalink between ground and air participants. I would think most aircraft could suffice with one antenna. One possible way to overcome LOS blockage is for each aircraft to transmit its complete traffic picture. That way gaps in coverage due to LOS issues are filled in with information from other network participants. Data fusion techniques would be required, though.