routes and all VR routes that accommodate operations above  1,500 feet AGL. IR routes are conducted in accordance with  IFR regardless of weather conditions. MTR are usually indicated with a blue line on the sectional  chart. A balloon pilot flying in the area of numerous VRs or  IRs should question the briefer during the weather brief to  find out if any of the routes are in use, and a possible time  frame for opening and closing. While it is true that the balloon  pilot has the right of way, the balloon will generally come out  worse in a midair conflict with a fast-moving military aircraft.  MTRs, such as the example depicted in  Figure 5-15,  are also  further defined on the back of the sectional charts. Controlled firing areas contain military 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. 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. Temporary flight restrictions (TFRs) are put into effect  when traffic in the airspace would endanger or hamper air or  ground activities in the designated area. For example, a forest  fire, chemical accident, flood, or disaster-relief effort could  warrant a TFR, which would be issued as a Notice to Airmen  (NOTAM). The NOTAM begins with the phrase “FLIGHT  RESTRICTIONS” followed by the location of the temporary  restriction, effective time period, area defined in statute miles,  and altitudes affected. The NOTAM also contains the FAA  coordination facility and telephone number, the reason for the  restriction, and any other information deemed appropriate. The  pilot should check the NOTAMs as part of flight planning. The reasons for establishing a temporary restriction are: Military Training Routes (MTRs) are routes used by military  aircraft to maintain proficiency in tactical flying. These routes  are usually established below 10,000 feet MSL for operations  at speeds in excess of 250 knots. Some route segments may  be defined at higher altitudes for purposes of route continuity.  Routes are identified as IFR (IR), and VFR (VR), followed by  a number. 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). IFR Low Altitude En Route Charts depict all IR  5-8 •  Prevent an unsafe congestion of sightseeing aircraft  above an incident or event, which may generate a high  degree of public interest; •  Provide a safe environment for the operation of  disaster relief aircraft; •  Protect persons and property in the air or on the surface  from an existing or imminent hazard; Military Training Routes (MTRs) Airport Advisory Areas Temporary Flight Restrictions (TFRs) Other Airspace Areas Controlled Firing Areas •  Airport advisory areas •  Military training routes (MTR) •  Temporary flight restrictions (TFR) •  National security areas “Other airspace areas” is a general term referring to the  majority of the remaining airspace. It includes: Figure 5-14.  Alert area (A-211). Figure 5-15.  Military training routes (MTR) chart symbols.