; (2) an assessment of the operational condition of the legacy systems in use, including the interoperability of such systems; (3) the average age of such legacy systems and, for each such legacy system, the intended design life of the system, by type; and (4) the availability of replacement parts, equipment, or technology to maintain such legacy systems. (e) Plan to accelerate drawdown, replacement, or enhancement of identified legacy systems (1) In general Not later than 120 days after the date on which the Administrator provides the report under subsection (d), the Administrator shall develop and implement a plan, in consultation with industry representatives, to accelerate the drawdown, replacement, or enhancement of any legacy systems that are identified in the audit required under subsection (a) as outdated, insufficient, unsafe, or unstable legacy systems. (2) Priorities In developing the plan under paragraph (1), the Administrator shall prioritize the drawdown, replacement, or enhancement of such legacy systems based on the operational risks such legacy systems pose to aviation safety and the costs associated with the replacement or enhancement of such legacy systems. (3) Collaboration with external experts In carrying out this subsection, the Administrator shall— (A) collaborate with industry representatives and other external experts in information technology to develop the plan under paragraph (1) within a reasonable timeframe; (B) identify technologies in existence or in development that, with or without adaptation, are expected to be suitable to meet the technical information technology needs of the FAA