Why on this SID chart (DVR6J from 09R at LHR) is it necessary to state an altitude restriction of "At 6,000" at 5d before DET, when an identical altitude restriction on this SID already exists at 16d before DET?
The departure is already capped at 6,000ft, so it seems a bit pointless as you can't climb again until cleared anyway. Same applies for the departure from the 27's (visible also on this image on the easterly track into DET) which has the 6,000ft restriction repeated at 29d and 5d.
Is it just to make doubly sure that pilots won't continue to climb above 6,000?
