If you have orders there's nothing anyone can do to stop you. You won't get paid by the FAA, but you won't lose your job. Personally I think the route to go would be train to CPC then take the extended leave. I'm no expert, but here's why:
Absent - Uniformed Service employee is absent (whether in pay or nonpay status) to perform duty with the uniformed services and has reemployment rights under the Uniformed Services Employment and Reemployment Rights Act (USERRA – 38 U.S. Code chapter 43)
(a)Subject to subsections (b), (c), and (d) and to section 4304, any person whose absence from a position of employment is necessitated by reason of
service in the uniformed services shall be entitled to the reemployment rights and benefits and other employment benefits of this chapter if—
(1)
notice of such service to such person’s employer;
(2)
service in the uniformed services does not exceed five years; and
(3)except as provided in subsection (f), the person reports to, or submits an application for reemployment to, such employer in accordance with the provisions of subsection (e).
(e) (1) (D)
In the case of a person whose period of
service in the uniformed services was for more than 180 days, by submitting an application for reemployment with the employer not later than 90 days after the completion of the period of service.
