时间:2011-09-26 01:01来源:蓝天飞行翻译 作者:航空 点击:次
Integrity Monitoring broadcasted from the particular GPS satellites used during a given flight. Onboard (RAIM) GPS navigators accomplish this automatically as the aircraft proceeds along its route. When insufficient signal integrity is detected an alarm is provided to the flightcrew. Using the predictive RAIM software flightcrews and dispatchers know in advance whether or not suitable GPS navigation will be available throughout the flight. This predictive information may also be determined during flight planning by contacting an FAA Flight Service Station. Reliable Fix A "reliable fix" means station passage of a VOR, VORTAC, or NDB. A reliable fix also includes a VOR/DME fix, an NDB/DME fix, a VOR intersection, an NDB intersection, and a VOR/NDB intersection provided course guidance is available from one of the facilities and the fix lies within the designated operational service volumes of both facilities which define the fix. Required Navigation A statement of navigation performance necessary for operations within a defined Performance (RNP) airspace. Required Navigation Applies to aircraft equipped with INS or IRU systems where those systems provide Performance (RNP) the means of navigation to navigate to the degree of accuracy required by ATC. Time Limit The FAA-approved time in hours--after the system is placed in navigation mode or is updated en route--that the specific INS or IRU make/model can meet a specific RNP type on a 95% probability basis. It is used to establish the area of operations or routes on which the aircraft/navigation system is qualified to operate. Required Navigation A value typically expressed as a distance in nautical miles from the intended |