How do pattern and overflight altitudes work for airports underneath Class C airspace? Lowell City Airport (24C) has an elevation of 700 feet MSL. So normally, the pattern altitude is going to be 1,700 feet, and the altitude for overflying the pattern is going to be 2,200 feet.

However, 24C Lowell is located underneath Class C airspace which starts at 2,000 MSL, so you can't fly at 2,200 without talking to Grand Rapids.

What should I do if I'd like to fly over the field? I can think of a few options:


Maybe 24C Lowell has a non-standard pattern altitude, like 1,400, which would allow me to overfly at 1,900. (How could I find this out using official sources?) 
Split the difference between pattern altitude and the Class C. If the pattern altitude is 1,700 and the Class C starts at 2,000, maybe I can overfly at 1,900.
Establish communications with Grand Rapids Approach, then go ahead and overfly at 2,200 while monitoring both Approach and CTAF at the same time. 
Just avoid overflying the pattern, and fly around it instead. 


When in doubt, I'm going with option 4. But what should I know about the other options?

I do have some particular questions about option 3. If I do choose to contact Grand Rapids Approach and climb to 2,200 to overfly, then I'll have to monitor both Approach and CTAF at the same time, right? Can most small airplanes even do that?
Just talk to the controllers. We live under a Class B with several underlying Class C or D fields. They'll talk to you. They'd rather know what you're planning to do than not, keeps everyone safer.