Our programmer on the EDC calibration is apparently running for office. He says, and I quote:
"I wouldn't be surprised if it works, and I wouldn't be surprised if it causes a small error."
So basically, we don't know. We do pay attention to the EFIS pitch as we calibrate, but we also made some assumptions that the compass rose was level. It's not something we planned for, but it also doesn't cause any obvious issues.
The best we can tell you is to try it, and see if your results are good or not.
You can also use a GPS to cal the EDC- Taxi the airplane until the GPS track reads the heading you want, then stop. This will get you pretty close to each heading.
