MART Vol. II MO/MP - NESA - Civil Air Patrol

Because the transmitters are satellite based, not ground based, and thesignals are essentially transmitted downward, system accuracy is not significantlydegraded in mountainous terrain. Additionally, the system is not normallyvulnerable to interference from weather or electrical storms. Receivers cantypically process as many as twelve received signals simultaneously, and canautomatically deselect any satellite whose signal doesn't meet specific receptionparameters. The system can function with reasonable accuracy using as few asthree received signals.To a new operator, the GPS is complex and can initially increase the user'sworkload. Pilots and observers must read the operating manual or instructionsand become thoroughly familiar with GPS operation before flight, so that operatingthe GPS will not become a distraction from more important tasks. Also, manymanufacturers have CD simulators that allow individuals to practice use of theGPS on a computer.CAP is standardizing the fleet with the Garmin Apollo GX55 (Figure 5-10) andthe G1000. Even if your aircraft has a different GPS, the basic functions are thesame.Figure 5-10All GPS units typically display bearing and distance to a waypoint, altitude,ground speed, estimated time to the waypoint (ETE), and ground track. GPSdatabases also contain extensive information about a selected waypoint (e.g., anairport) such as runway length and alignment, lighting, approaches, frequencies,and even FBO details such as the availability of 100LL fuel and hours ofoperation.The GPS receiver allows the pilot to:Fly directly to any positionThe ability to fly directly to any position (e.g., an airport, navaid, intersection,or user waypoint) saves time and fuel. This reduces transit time, thusallowing more of the crew’s allowed duty day to be spent in the search area.Any of these positions can be entered as the destination through a simpleprocedure. Additionally, all GPS have a "Nearest Airport" and "Nearest VOR"function, where you can easily display a list of the nearest airports or VORsand then select it as your destination. Positions can also be grouped intoflight plans.Once the destination is entered into the GPS, the heading and the groundtrack can be monitored. By matching the heading and ground track (orkeeping the CDI centered), you are automatically compensating for wind andthus flying the shortest possible route to your destination. The GX55 andG1000 have a Moving Map feature that simplifies this task.82