Starting with the current chart cycle from August 22, the radius of protected airspace for new circling approach procedures has increased.
This change will mainly affect airplanes in approach categories B through D.
While the procedures are flown in the same way, the requirements for a larger protected airspace may result in higher altitudes being flown.
For example, if your destination is the Traverse City (KTVC) GPS RWY 36 approach, the category C minimum descent altitude (MDA) has increased from 1,280 ft to 1,500 ft. The category D MDA changed from 1,300 ft to 1,720 ft, and so on. The good news is that this approach was also revised to include an LPV decision altitude of 898 ft.
Several of these new procedures can be found under East Tawas, Hancock, Hillsdale, and Traverse City.
The explanation of the new “expanded circling approach maneuvering airspace radius” is on page B2 of the Terminal Procedures Publication (TPP). In short, there is a new “negative C” symbol that appears in the minimums area of each new procedure to indicate expanded protected airspace. With this update to the TPP, the other explanations of circling approach areas are somewhat obsolete. In particular, I would avoid using Figure 5-4-26 in the Aeronautical Information Manual, or Figure 5-3 in the Instrument Procedures Handbook until these books get updated.