zeffy:
In the USA, the maximum climb gradient for ODP's/SID's is only 500'/nm -- typically not a problem for jets.
That is the "baseline" maximum climb gradient. Proposed gradients in excess of 500'/nm must be submitted by the FAA's procedures design office to Flight Standard's Performance Review Board. That Board has a giant rubber stamp that says, "Approved, the Skies the Limit." (ala KTVL Runway 18, et al.)