cta step buffer?

[ISABELL]

hi there,
can't find it witten anywhere but is there a published vertical buffer height for cta clearance? ie if a lower limit of ctr is say 1000? is there room for error/planning ie to 1100ft? or do you need to plan to fly at say 900ft to avoid ctr? if so where do i find this? sorry not worded very well... any help is appreciated....

[melbATC]

In Australia ATC are required to separate aircraft subject to a clearance in CTA from the lower level of CTA by at least 500ft increasing to 1000ft if there is any known traffic at the level of the base of CTA

We also consider when using radar, an aircraft giving a mode c level readout within +-200ft of a level to be maintaining the level.

So to answer your question planning to fly at the base of CTA would be fine.

[ISABELL]

thanks melbATC, handy to know.