Ensure that waivers of the wake turbulence separation standards are: (i) restricted to VMC, by day only; and (ii) specifically acknowledged by pilots with words such as "ACCEPT WAIVER"; and (iii) not permitted under certain circumstances, for example:
when a light aircraft:
(a) will take-off behind a heavy or medium aircraft from a point on the runway more than 150 m beyond where the heavy or medium aircraft started its take-off roll; or
(b) will take-off in the opposite direction to a heavy or medium aircraft that has just taken-off from, or carried out a missed approach to, the same runway; or
when a medium aircraft:
(c) will take-off behind a heavy aircraft from a point on the runway more than 150 m beyond where the heavy aircraft started its take-off roll; or
(d) will take-off in the opposite direction to a heavy aircraft that has just taken-off from, or carried out a missed approach to, the same runway. (This is similar to the Australian restrictions on granting waivers.)