As far as I know, we do have different requirements on GA Climb Gradients:
- Certification requirements:
CS25/FAR25:
Landing Climb Gradient of 3,2% (All Engine; LDG Configuration) - not limiting on most jets.
Approach Climb Gradient of 2,1% (2 ENG), 2,4% (3 ENG), 2,7% (4 ENG) (OEI; Appr. Config - i.e. Gear Up) - might be limiting
- Procedure Design Requirements:
PANS OPS / ICAO Doc 8168 2,5% (All ENG)
TERPS / FAA Order 8260.3D:
It states in "2-8 -5. Straight Missed Approach Obstacle Clearance." that a 40:1 surface should not be penetrated, which leads to 2,5% (regardless of configuration and engine availability).
It states in "2-1-4.Sloping OCS." under point "b.Climbing on departure or missed approach." the following: "(...) The minimum climb gradient that will provide adequate ROC in the climb segment is 200 ft/nautical mile (NM), unless a higher gradient is specified." Those 200ft/NM would lead to a 3.3% gradient.
The above mentioned TERPS excerpts call for either 2.5% or 3.3%. My company tells me, that within the TERPS Area (US and CAN) the required gradient for GA (OEI and All ENG) will be increased to 3,3%.
What are the requirements? Do we need 3.3%, or do we need 2.5%?
I appreciate any hint!