These charts are intended for use by pilots operating from airfields within or near Class B and Class C airspace. Coverage of Terminal Area Charts are indicated by shaded boxes on the Sectional Chart index. These charts are updated every six months, Puerto Rico-Virgin Islands annually.Charted VFR Flyway Planning Charts are printed on the backs of selected Terminal Area Charts. Separate indices show the coverage of VFR Charts (Conterminous U.S. and Alaska).hese charts are updated every six months, Puerto Rico-Virgin Islands annually. Charted VFR Flyway Planning Charts are printed on the backs of selected Terminal Area Charts. Separate indices show the coverage of VFR Charts (Conterminous U.S. and Alaska).