Controlled firing areas contain activities, which, if not conducted in a controlled environment, could be hazardous to nonparticipating aircraft. The difference between controlled firing areas and other special use airspace is that activities must be suspended when a spotter aircraft, radar, or ground lookout position indicates an aircraft might be approaching the area.

“Other airspace areas” is a general term referring to the majority of the remaining airspace. It includes:

An airport advisory area is an area within 10 statute miles (SM) of an airport where a control tower is not operating, but where a flight service station (FSS) is located. At these locations, the FSS provides advisory service to arriving and departing aircraft.

Military training routes (MTR) are developed to allow the military to conduct low-altitude, high speed training. The routes above 1,500 feet AGL are developed to be flown primarily under IFR, and the routes 1,500 feet and less are for VFR flight. The routes are identified on sectional charts by the designation “instrument (IR) or visual (VR).” MTRs with no segment above 1,500 feet AGL are identified by four number characters; e.g., IR1206, VR1207. MTRs that include one or more segments above 1,500 feet AGL are identified by three number characters; e.g., IR206, VR207.

An FDC Notice to Airmen (NOTAM) will be issued to designate a temporary flight restriction (TFR). The NOTAM will begin with the phrase “FLIGHT RE- STRICTIONS” followed by the location of the temporary restriction, effective time period, area defined in statute miles, and altitudes affected. The NOTAM will also contain the FAA coordination facility and telephone number, the reason for the restriction, and any other information deemed appropriate. You should check the NOTAMs as part of flight planning. Flight Service (1-800-WX-BRIEF) can advise you on current TFRs.

Some of the purposes for establishing a temporary restriction are:

Parachute jump areas are published in the Airport/Facility Directory. Sites that are used frequently are depicted on sectional charts.

Published VFR routes are for transitioning around, under, or through some complex airspace. Terms such as VFR flyway, VFR corridor, Class B airspace, VFR transition route, and terminal area VFR route have been applied to such routes. These routes are generally found on VFR terminal area planning charts.

Terminal Radar Service Areas (TRSA) are areas where participating pilots can receive additional radar services. The purpose of the service is to provide separation between all IFR operations and participating VFR aircraft.

The primary airport(s) within the TRSA become(s) Class D airspace. The remaining portion of the TRSA overlies other controlled airspace, which is normally Class E airspace beginning at 700 or 1,200 feet and established to transition to/from the en route terminal environment. TRSAs are depicted on VFR sectional charts and terminal area charts with a solid black line and altitudes for each segment. The Class D portion is charted with a blue segmented line.