In a previous post I asked about departure frequency and the use of it when not guiding aircraft in altitude.
Yes. (However these do sometimes get cancelled by ATC in real life, depending on traffic levels or whether or not direct-to clearances are received that effectively mean skipping part of the SID.)
There are in fact several types of altitude constraint:
All altitude constraints, however, are represented in IF as the third category - it’s a good idea to double check with charts to find out which of those they actually are.
For example:
WELDA is 6000 and above; SPOON 15000 and below, ROVER 12000 and above, etc.
I’ve always took it as working in conjunction with the STARS altitudes. So your restricted so you stay below or above aircraft on arrivals coming in from the way you are going out.
Like for airports around EGLL. You stay at 6000ft until out of the vicinity for examples.
So the listed altitudes are overall an idea of the altitudes in which the plane should be around such as SPOON being below 15,000ft and ROVER being above 12,000ft so when flying in between those two points that is around the range in altitude you should attempt to be at?
In theory yes. However the actual altitude at each waypoint will be dependent on your climb profile and climb rate (which will differ between aircraft and at different weights.)
So it’s just a general idea of how the climbs should look. But a lighter aircraft will obviously be able to climb quicker than a heavier one. My climb out of RJTT to KJFK with a very heavy load was much lower anywhere from 1,400 to 2,200 v/s. Which is typically lower than I would with a shorter flight due to weight.
