FYI: The NATCA union that ph66 mentioned (Nat'l. Air Traffic Controllers Association) has mostly ATC employees covered under it, and is a very good/ honorable and strong professional labor organization. it has a number of other bargaining units with non-ATC FAA employees; I was an Engineer in FAA and a proud member of NATCA for 25+ years before retiring (at the normal FERS full-retirement age, MRA + 30 at a minimum).
... Anyway, those other bargaining units are covered under different contracts than the ATC contract with FAA, so those differ in many ways in their articles & provisions. However, most if not all of those NATCA contracts currently include the FERS sick-leave buy-back option for retirees that ph66 outlines in their comments (note that sick leave abuse I think was not common in our ranks, and I highly agree w/ ph66's last sentence, and with the argument for increasing the SL cash-out amounts). Like ph66, I too recall that I took that cash-out option for my large sick-leave balance upon retirement, after my assessment of that against the option to convert those hours to time-in-service for pension computation purposes.
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