1-15  Figure 1-15. Diverse Departure Obstacle Assessment to 25/46 NM.  Figure 1-14. Previous TERPS departure procedures.  Beyond the diverse obstacle assessment  area (25/46 NM) there might be significantly  higher obstacles.  Aircraft reaches en route obstacle  clearance of 1,000' (nonmountainous  areas) or 2,000' (in mountainous areas).  TERPS Design CG of 200 ft/ NM  40:1 OIS at 152 ft/ NM  4NM  25/46 NM   '' 1 NM  2 NM  10 NM  200 f eet  400 f eet  V186 Positive course guidance must be acquired  within 10 NM for straight departures and  within 5 NM for departures requiring turns.  Required climb gradient of 200 ft/NM  Previous TERPS Departure Procedures  Obstacle clear anc e sur fac e ( OCS) 35 feet feet  152 feet 304 feet feet  96 feet 48 48 