; and (3) the average age of in-service legacy systems and, for each legacy system in use, the intended design life of the system, by type. (e) Collaboration with industry on plan to accelerate drawdown, replacement, or enhancement of legacy systems (1) In general Not later than 120 days after the date on which the Administrator provides the report required by subsection (d), the Administrator shall initiate a plan, in coordination with industry, to accelerate drawdown, replacement, or enhancement of any legacy systems that are identified in the audit required by subsection (a) as outdated, insufficient, unsafe, or unstable. (2) Priorities The Administrator shall prioritize the drawdown, replacement, or enhancement of such legacy systems based on the operational risks such legacy systems pose to air safety and the costs associated with the replacement or enhancement of such legacy systems. (3) Collaboration The Administrator shall work with industry to develop a plan to replace or enhance the identified legacy systems within a reasonable time frame. (4) Progress updates The Administrator shall provide the appropriate committees of Congress with semi-annual updates on the progress made in replacing or enhancing the identified legacy systems. (f) Definitions In this section: (1) Industry The term industry means the aviation industry, limited to organizations with expertise in aviation-dedicated network systems, systems engineering platforms, aviation software services, air traffic management, flight operations, and International Civil Aviation Organization (ICAO) standards. (2) Legacy systems The term legacy systems means any communication, navigation, surveillance, or automation or network applications or ground-based aviation infrastructure owned by the FAA that were deployed prior to the year 2000, including the Notice to Air Missions (NOTAM) system. (3) Outdated, insufficient, unsafe, or unstable The term outdated, insufficient, unsafe, or unstable means a legacy system for which the likelihood of failure