Finally have some time to study sectionals. Just one question. For airports that already have B space, there is no C space altitudes. Shouldn't C altitudes indicated same way as B space altitudes (one number over another)? For example, the C space for New York's JFK extends 30 miles out; but there is no altitudes. The out most B space ring has altitudes of 70/15. Should I just use those numbers for C space in this particular case?

>Finally have some time to study sectionals. Just one>question. For airports that already have B space, there is no>C space altitudes. Shouldn't C altitudes indicated same way as>B space altitudes (one number over another)? For example, the>C space for New York's JFK extends 30 miles out; but there is>no altitudes. The out most B space ring has altitudes of>70/15. Should I just use those numbers for C space in this>particular case?C and B space are typically shown the same, but each are different. B space is typically the largest/busiest airports, C are a slight 'step down' from your New Yorks or Bostons or Chicago's etc., but still city airports. Regardless, B & C both show altitude 'layers'.You might be talking about D & E spaces, which do not show altitude numbers. Typically D space is 2,500', and E space is 700'.Here is a good tutorial, written for a hang gliding club, but still relevant. http://www.flytandem.com/airspace.htmHere are screen shots of New York, class B, and below (on the same sectional) class C around Allentown:http://forums.avsim.net/user_files/152357.jpghttp://forums.avsim.net/user_files/152358.jpg

This is the line I am talking about.

That line is not refering to class C airspace. It is the boundary that you have to have an operating transponder with "mode C" capability (means that your altitude is encoded and sent with your transponder signal even if you are VFR squawking 1200).

I finally got up to the Mode C section in the book. Thank you for the patience.