时间：2011-04-18 00:47来源：蓝天飞行翻译 作者：航空 点击：次
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5.The FAA has completed installation of 25 WRSs, 2 WMSs, 4 GUSs, and the required terrestrial communications to support the WAAS network. Prior to the commissioning of the WAAS for public use, the FAA has been conducting a series of test and validation activities. Enhancements to the initial phase of WAAS will include additional master and reference stations, communication satellites, and transmission frequencies as needed. 6.GNSS navigation, including GPS and WAAS, is referenced to the WGS.84 coordinate system. It should only be used where the Aeronautical Information Publications (including electronic data and aeronautical charts) conform to WGS.84 or equivalent. Other countries civil aviation authorities may impose additional limitations on the use of their SBAS systems. b. Instrument Approach Capabilities 1.A new class of approach procedures which provide vertical guidance, but which do not meet the ICAO Annex 10 requirements for precision ap-proaches has been developed to support satellite navigation use for aviation applications worldwide. These new procedures called Approach with Vertical Guidance (APV), are defined in ICAO Annex 6, and include approaches such as the LNAV/VNAV procedures presently being flown with barometric vertical navigation (Baro.VNAV). These approaches provide vertical guidance, but do not meet the more stringent standards of a precision approach. Properly certified WAAS receivers will be able to fly these LNAV/VNAV procedures using a WAAS electronic glide path, which eliminates the errors that can be introduced by using Barometric altimetery. 2.A new type of APV approach procedure, in addition to LNAV/VNAV, is being implemented to take advantage of the high accuracy guidance and increased integrity provided by WAAS. This WAAS generated angular guidance allows the use of the same TERPS approach criteria used for ILS approaches. The resulting approach procedure minima, titled LPV (localizer performance with vertical guidance), may have a decision altitude as low as 200 feet height above touchdown with visibility minimums as low as 1/2 mile, when the terrain and airport infrastructure support the lowest minima. LPV minima is published on the RNAV (GPS) approach charts (see paragraph 5.4.5, Instrument Approach Procedure Charts). 3. A new nonprecision WAAS approach, called Localizer Performance (LP) is being added in locations where the terrain or obstructions do not allow publication of vertically guided LPV proced-ures. This new approach takes advantage of the angular lateral guidance and smaller position errors provided by WAAS to provide a lateral only procedure similar to an ILS Localizer. LP procedures may provide lower minima than a LNAV procedure due to the narrower obstacle clearance surface. NOTE. WAAS receivers certified prior to TSO C.145b and TSO C.146b, even if they have LPV capability, do not contain LP capability unless the receiver has been upgraded. Receivers capable of flying LP procedures must contain a statement in the Flight Manual Supplement or Approved Supplemental Flight Manual stating that the receiver has LP capability, as well as the capability for the other WAAS and GPS approach procedure types. 4. WAAS provides a level of service that supports all phases of flight, including LNAV, LP, LNAV/VNAV and LPV approaches, within system coverage. Some locations close to the edge of the coverage may have a lower availability of vertical guidance. c. General Requirements 1. WAAS avionics must be certified in accordance with Technical Standard Order (TSO) TSO.C145A, Airborne Navigation Sensors Using the (GPS) Augmented by the Wide Area Augmenta-tion System (WAAS); or TSO.146A, Stand.Alone Airborne Navigation Equipment Using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS), and installed in accordance with Advisory Circular (AC) 20.130A, Airworthiness Approval of Navigation or Flight Management Systems Integrating Multiple Naviga-tion Sensors, or AC 20.138A, Airworthiness 1.1.38 Navigation Aids Approval of Global Positioning System (GPS) Navigation Equipment for Use as a VFR and IFR Navigation System. 2.GPS/WAAS operation must be conducted in accordance with the FAA.approved aircraft flight manual (AFM) and flight manual supplements. Flight manual supplements will state the level of approach procedure that the receiver supports. IFR approved WAAS receivers support all GPS only operations as long as lateral capability at the appropriate level is functional. WAAS monitors both GPS and WAAS satellites and provides integrity. 3.GPS/WAAS equipment is inherently capable of supporting oceanic and remote operations if the operator obtains a fault detection and exclusion (FDE) prediction program. 4.Air carrier and commercial operators must meet the appropriate provisions of their approved operations specifications. 5.Prior to GPS/WAAS IFR operation, the pilot must review appropriate Notices to Airmen (NOTAMs) and aeronautical information. This information is available on request from an Automated Flight Service Station. The FAA will provide NOTAMs to advise pilots of the status of the WAAS and level of service available. (a)The term UNRELIABLE is used in conjunction with GPS and WAAS NOTAMs. The term UNRELIABLE is an advisory to pilots indicating the expected level of WAAS service (LNAV/VNAV, LPV) may not be available; e.g., !BOS BOS WAAS LPV AND LNAV/VNAV MNM UNREL WEF 0305231700 . 0305231815. WAAS UNRELIABLE NOTAMs are predictive in nature and published for flight planning purposes. Upon commencing an approach at locations NOTAMed WAAS UNRELIABLE, if the WAAS avionics indicate LNAV/VNAV or LPV service is available, then vertical guidance may be used to complete the approach using the displayed level of service. Should an outage occur during the approach, reversion to LNAV minima may be required. (1)Area.wide WAAS UNAVAILABLE NOTAMs indicate loss or malfunction of the WAAS system. In flight, Air Traffic Control will advise pilots requesting a GPS or RNAV (GPS) approach of WAAS UNAVAILABLE NOTAMs if not contained in the ATIS broadcast. |
