Their depth of knowledge, commitment and responsiveness under questioning materially benefited the quality and completeness of this study. Sensitivity analyses were performed to determine the sensitivity of the overall rankings to the weighting factors of the various metrics. It is operationally flexible and synergistic with numerous emerging concepts that rely on aeronautical data link. It is relatively low cost and low risk, and it is free of technical defects that could affect integrity or operational usefulness. It has the philosophical support of a reasonable segment of the aviation community, it is being discussed within multiple ICAO panels, and demonstration programs in Sweden and elsewhere have been successfully completed.
Operational systems are in existence, or planned, in Sweden and Malaysia.
Substantial capacity increases could be achieved with relatively straightforward reoptimization, but additional programmatic delay would ensue as the protocol is adjusted and finalized. However, it was penalized for its lack of compatibility with current NAS systems and the relative lack of maturity surrounding the data link standard. In the far term, it may, actually emerge as the preferred means of supporting automatic dependent surveillance in the air as well as on the surface, while providing a synergistic platform for other applications. It is likely to achieve more rapid penetration of the GA community than equivalent Mode S equipment and systems. On the other hand, it is currently less mature, offers no benefit to ASTA per se relative to the air carrier community already equipped with Mode S, and its use is not likely to be mandated for the foreseeable future.