The 3 year BE is for NCMs, Officers sign Short service engagements (SSE) or Short engagements (SE). The length of the SSE or SE is dependant on your entry plan but I think in most cases an SSE is 9 years. I'll give you my numbers as an example, I enrolled on 16 Jun 99, my SSE took me to 15 Jun 08, once I got my pilot wings I am under restricted release until 02 Apr 11. So since my contract expires before my restricted release date, I had to sign either an IE or an SE. The SE would have been from 15 Jun 08 - 02 Apr 11, while the IE will take me to my 20 yrs on 15 Jun 2019.
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