Another important point to bare in mind is that the climb gradients are invariably posted as 'gross' limitations'. The charts in the AFM generally denotes gross climb. Knock off 8% for net. Many FAR 23 certified aircraft really only have 3 climb segments. Most, if not all FAR 25 aircraft (please pardon my lack of knowledge....I may not be 100% correct....it's been a long time) have 4 segments of climb. The reason I say 3 is that positive rate, in some schools of thought, is not considered climb, hence 3.
The first is the 'clean up', ie flaps, at 400' unless the company is using tabulated data and that info alone will denote the clean up altitude. At this point the aircraft is accelerated to VYSE and any additional power modes are activated, ie water meth (again FAR 23 aircraft). Very few aircraft have this option, the TPE331 comes to mind. And there are limitations on the use of meth. 5 minutes from memory. At 1500' AGL the last of additional power (3rd segment) comes into play (reserve power for instance) and then it's a case of following the SID, or the escape procedure as documented in the tab data, to avoid terrain.
Jets are a little different as they mostly stay at TO power until Max Continuous is selected in the EO situation and you just do your best but essentially clean up at acceleration alt and vyse or Vclean until clear of terrain.
Again it's been a while since I worked this stuff but essentially it's good to know. Knowing the percentages is one thing but when you're in the **** and fighting with an aircraft thats down on an engine the procedure to get the thing above the terrain is the most important thing to know. SOP will 9.9 times out of 10 have you home at the end of an otherwise ordinary day.
Not sure if this will help. Hope it does.
Regards
D
