Just a note to address an error that many make on departure procedures. The standard climb gradient for departures at airports that have had a diverse departure assessment done (any airport that has been terped to develop an instrument approach will also have a diverse departure assessment done) is 200 FPNM which must be maintained to the enroute environment, which is considered to be either the minimum altitude for IFR operations per FAR 91.177 if on an uncharted route, or the MEA if on an airway, or the altitude assigned by ATC. When a non-standard (increased) climb gradient (CG) is required, such as the departure from Rwy 24 out of KELM referenced by Mr. Barrett above, the increased CG must be accompanied by the MSL altitude to which the increased CG must be maintained to. However, once that MSL altitude is reached, you are still required to now maintain the minimum climb gradient (200 FPNM) beyond that listed MSL altitude until you then reach the enroute environment altitude as explained prior. The increased CG and corresponding MSL altitude are to ensure required obstacle clearance (ROC) for a specific obstacle in the departure area, whereas the standard 200 FPNM CG ensures ROC to the enroute environment. So, in fact, there is still a requirement to maintain a certain CG beyond the 2300' MSL in the departure procedure referred to above out of KELM in Elmira/Corning, New York. This is referenced in both the FAA Instrument Procedures Handbook and TERPS order 8260.46 c, Departure Procedures Program.
