时间：2011-04-18 00:50来源：蓝天飞行翻译 作者：航空 点击：次
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1. The minima lines are: (a)GLS. “GLS” is the acronym for GNSS landing system; GNSS is the ICAO acronym for Global Navigation Satellite System (the international term for all GPS type systems). This line was originally published as a placeholder for both WAAS and LAAS minima and marked as N/A since no minima was published. As the concepts for LAAS and WAAS procedure publication have evolved, GLS will now be used only for LAAS minima, which will be on a separate approach chart. Most RNAV(GPS) approach charts have had the GLS minima line replaced by a WAAS LPV line of minima. (b)LPV. “LPV” is the acronym for localizer performance with vertical guidance. LPV identifies WAAS APV approach minimums with electronic lateral and vertical guidance. The lateral guidance is equivalent to localizer and the protected area for LPV procedures is now the same as for an ILS. The obstacle clearance area is considerably smaller than the LNAV/VNAV protection, allowing lower minima in many cases. Aircraft can fly this minima line with a statement in the Aircraft Flight Manual that the installed equipment supports LPV approaches. This includes Class 3 and 4 TSO.C146 WAAS equipment. (c)LNAV/VNAV. LNAV/VNAV identifies APV minimums developed to accommodate an RNAV IAP with vertical guidance, usually provided by approach certified Baro.VNAV, but with lateral and vertical integrity limits larger than a precision approach or LPV. LNAV stands for Lateral Navigation; VNAV stands for Vertical Navigation. This minima line can be flown by aircraft with a statement in the Aircraft Flight Manual that the installed equipment supports GPS approaches and has an approach.approved barometric VNAV, or if the aircraft has been demonstrated to support LNAV/VNAV approaches. This includes Class 2, 3 and 4 TSO.C146 WAAS equipment. Aircraft using LNAV/VNAV minimums will descend to landing via an internally generated descent path based on satellite Arrival Procedures 5.4.20 or other approach approved VNAV systems. Since electronic vertical guidance is provided, the minima will be published as a DA. Other navigation systems may be specifically authorized to use this line of minima, see Section A, Terms/Landing Minima Data, of the U.S. Terminal Procedures books. (d)LP. “LP” is the acronym for localizer performance. LP identifies nonprecision WAAS procedures which are equivalent to ILS Localizer procedures. LP is intended for use in locations where vertical guidance cannot be provided due to terrain or other obstacles. The protected area is considerably smaller than the area for LNAV lateral protection and will provide a lower MDA in many cases. WAAS equipment may not support LP, even if it supports LPV, if it was approved before TSO C.145B and TSO C.146B. Receivers approved under previous TSOs may require an upgrade by the manufacturer in order to be used to fly to LP minima. Receivers approved for LP must have a statement in the approved Flight Manual or Supplemental Flight Manual including LP as one of the approved approach types. LPV and LP cannot be published as part of the same instrument procedure due to the inability to change integrity limits during an approach. (e)LNAV. This minima is for lateral navigation only, and the approach minimum altitude will be published as a minimum descent altitude (MDA). LNAV provides the same level of service as the present GPS stand alone approaches. LNAV minimums support the following navigation systems: WAAS, when the navigation solution will not support vertical navigation; and, GPS navigation systems which are presently authorized to conduct GPS approaches. Existing GPS approaches continue to be converted to the RNAV (GPS) format as they are revised or reviewed. NOTE. GPS receivers approved for approach operations in accordance with: AC 20.138, Airworthiness Approval of Global Positioning System (GPS) Navigation Equipment for Use as a VFR and IFR Supplemental Navigation System, for stand.alone Technical Standard Order (TSO) TSO.C129 Class A(1) systems; or AC 20.130A, Airworthiness Approval of Navigation or Flight Management Systems Integrating Multiple Navigation Sensors, for GPS as part of a multi.sensor system, qualify for this minima. WAAS navigation equipment must be approved in accordance with the requirements specified in AIM TSO.C145 or TSO.C146 and installed in accordance with Advisory Circular AC 20.138A, Airworthiness Approval of Global Navigation Satellite System (GNSS) Equipment. 2. Other systems may be authorized to utilize these approaches. See the description in Section A of the U.S. Terminal Procedures books for details. These systems may include aircraft equipped with an FMS that can file /E or /F. Operational approval must also be obtained for Baro.VNAV systems to operate to the LNAV/VNAV minimums. Baro.VNAV may not be authorized on some approaches due to other factors, such as no local altimeter source being available. Baro.VNAV is not authorized on LPV procedures. Pilots are directed to their local Flight Standards District Office (FSDO) for additional information. NOTE. RNAV and Baro.VNAV systems must have a manufacturer supplied electronic database which shall include the waypoints, altitudes, and vertical data for the procedure to be flown. The system shall also be able to extract the procedure in its entirety, not just as a manually entered series of waypoints. 3. ILS or RNAV (GPS) charts. Some RNAV (GPS) charts will also contain an ILS line of minima to make use of the ILS precision final in conjunction with the RNAV GPS capabilities for the portions of the procedure prior to the final approach segment and for the missed approach. Obstacle clearance for the portions of the procedure other than the final approach segment is still based on GPS criteria. NOTE. Some GPS receiver installations inhibit GPS navigation whenever ANY ILS frequency is tuned. Pilots flying aircraft with receivers installed in this manner must wait until they are on the intermediate segment of the procedure prior to the PFAF (PFAF is the active waypoint) to tune the ILS frequency and must tune the ILS back to a VOR fre-quency in order to fly the GPS based missed approach. |
