IFH 1-7

Figure 8-3. En route airport legend.Figure 1-3. En route airport legend. fix without attaining the MRA. On AeroNav Products charts, the MRA is indicated by the symbol and the altitude preceded by “MRA” (e.g., “MRA 9300”). [Figure 1-2] The minimum crossing altitude (MCA) is charted when a higher MEA route segment is approached. The MCA is usually indicated when a pilot is approaching steeply rising terrain and obstacle clearance and/or signal reception is compromised. In this case, the pilot is required to initiate a climb so the MCA is reached by the time the intersection is crossed. On AeroNav Products charts, the MCA is indicated by the symbol , and the Victor airway number, altitude, and the direction to which it applies (e.g. “V24 8000 SE”). The maximum authorized altitude (MAA) is the highest altitude at which the airway can be flown with assurance of receiving adequate navigation signals. Chart depictions appear as “MAA-15000.” When an MEA, MOCA, and/or MAA change on a segment other than at a NAVAID, a sideways “T” ( ) is depicted on the chart. If there is an airway break without the symbol, one can assume the altitudes have not changed (see the upper left area of Figure 1-2). When a change of MEA to a higher MEA is required, the climb may commence at the break, ensuring obstacle clearance. [Figure 1-4] Navigation Features Types of NAVAIDs Very high frequency omnidirectional ranges (VORs) are the principal NAVAIDs that support the Victor and Jet airways. Many other navigation tools are also available to the pilot. For example, nondirectional beacons (NDBs) can broadcast signals accurate enough to provide stand-alone approaches, and DME allows the pilot to pinpoint a reporting point on the airway. Though primarily navigation tools, these NAVAIDs can also transmit voice broadcasts. Tactical air navigation (TACAN) channels are represented as the two- or three-digit numbers following the three-letter identifier in the NAVAID boxes. The AeroNav Products terminal procedures provide a frequency-pairing table for the TACAN-only sites. On AeroNav Products charts, very- high frequencies and ultra-high frequencies (VHF/UHF) NAVAIDs (e.g., VORs) are depicted in black, while low frequencies and medium frequencies (LF/MF) are depicted as brown. [Figure 1-5] Identifying Intersections Intersections along the airway route are established by a variety of NAVAIDs. An open triangle indicates the location of an ATC reporting point at an intersection. If the triangle is solid , a report is compulsory. [Figure 1-4] NDBs, localizers,