Depending on certain factors, you can accept a SID clearance knowing that you cannot make the required climb gradient with one engine inoperative (OEI).
The FAA Aeronautical Information Manual (AIM) 5-2-8 ODP and SIDs states this:
ODPs and SIDs assume normal aircraft performance, and that all engines are operating (AEO). Development of contingency procedures, required to cover the case of an engine failure or other emergency in flight that may occur after liftoff, is the responsibility of the operator.
This answer begs another question and what are some contingency procedures you can consider when accepting a SID when the required climb gradient is not possible with OEI procedures?
The FAA lists two possible places for this information:
- AC 120-91 - Airport Obstacle Analysis
- Instrument Procedures Handbook (FAA-H-8261-1) Chapter 1.
AC 120-91 talks about how runway analysis is used to comply with Part 121 / 135 obstacle climb requirement.
Instrument Procedures Handbook provides additional information on how OEI takeoff obstacle clearance requirements are different than TERPS requirements. Besides using runway analysis, there isn't a lot of additional information on contingency procedures.
Here are my contingency procedures in the preferred order
- Runway Analysis - Let an engineer figure out the maximum weight to takeoff and be able to climb above the obstacles
- Radar vectors - Once ATC issues the words "Turn left / right heading xxx°" they are equally responsible for terrain clearance
- See and avoid the terrain (VMC only) - If we can see the obstacles... hopefully we can miss them. Of course, mountains don't care if you can see them or not. They don't move.
- Obstacle Departure Procedures (ODP) using OEI calculations.
- SID using OEI calculations.
It would be great if others come up with a different set. I would love to see them. I will typically work through this listing and if I am taking off from an airport without radar services in IMC where I do not have runway analysis, I need to be able to make the ODP or the SID on OEI performance.