For currency/recency, we had to bridge a gap, or at least try to. The SC-196 came up with an "events" based currency/recency, an event being a take off or landing whilst being the sole manipulator of the controls. As this terminology and implementation was such a new concept, the industry rejected it in favour of a more traditional system based on hours. The last modification done was to recognise that NVG experience is valuable, like the point that Delta TQ was making, and we split currency/recency based on experience. This also aligns with the Oz Army who have tighter requirements on the more junior guys. It was then mapped around the IFR and NVFR 90 day cycle as a start point.
Note that you also have to be current/recent for the operation for NVFR (and IFR if that's what you are). Again the disclaimer: this is NOT the final draft: just the current proposal and a ratified industry position modified by CASA requirements.
NVG Pilots must meet the minimum following recency, or a NVG proficiency check flight will be required:
Less than 100 hours NVG Flight Time as a Pilot
NVG Flight time: 3 hours for command pilots, 1 hour for co-pilots in last 3 months OR proficiency check in last 3 months. 3 hours in 6 months if over 100 hours NVG.
NVG Proficiency Check: 6 monthly. Annually if over 100 hours NVG.
For Ops below 500ft AGL: 3 takeoffs, circuits and landings in last 3 months. In 6 months if over 100 hours NVG.
For ops to HLS other than a Standard HLS for NVG: 3 takeoffs, circuits and landings to an unlit HLS devoid of surrounding cultural lighting in 3 months – can be done unaided. An area is considered devoid of cultural lighting if, at 500 ft AGL, there is insufficient ground lights to maintain an unaided visible horizon. In 6 months if over 100 hours NVG.
NVG Aircrew Members must also meet the minimum following recency, or an NVG proficiency check flight will be required:
Less than 50 hours NVG Flight Time:
NVG Flight time: 2 hours in last 3 months OR proficiency check in last 3 months. @ hours in last 6 months if over 50 hours NVG.
NVG Proficiency Check: 6 monthly. Annually if over 50 hours NVG.
For ops (including winch or sling) to a HLS other than a Standard HLS for NVG: 2 NVG takeoffs, circuits and landings, to an unlit HLS devoid of surrounding cultural lighting in 3 months. An area is considered devoid of cultural lighting if, at 500 ft AGL, there is insufficient ground lights to maintain an unaided visible horizon. In 6 months for over 50 hours NVG.
These proposals come with the call to tailor the minimums to the operation, such that a non instrument rated operation may add IF currency, or you may choose to use the 100 hour reductions only with 100 hours PIC. This will be operator dependant.