GPS notams

GPS Â… the mainstay for the Cirrus and many other airplanes is becoming a frustrating experience. I thought I would share my experience with the Garmin 430 and flying on the West Coast. For those of you that are not aware one needs to monitor signal strength in order to fly IFR and more importantly fly IFR GPS approaches. The Garmin 430 has the ability to monitor signal strength (RAIM Â… which must stand for something that I don’t remember, but it is an indication of signal strength). Within the last several months I have able to fly up and down the coast from Redding, CA to San Diego, CA. Many times I get the message “RAIM not available” and the yellow message light comes on indicating that the GPS cannot be used for IFR navigation Â… bummer! What is frustrating even more is that there are notams issued for the GPS being “unreliable” in areas that are noted by lat/long. Generally, there are 4 to 8 lat/long locations required to "map out the unreliable coverage areas AND there are multiple area notamed. What a pain. Some of the notams are sneaky in that they say they are for a few days duration, but then are posted again for another few days. This problem is not Cirrus or Garmin, but I suspect our wonderful government playing with the system for military purposes. The point of this tirade is simply to make those of you that think GPS is the end all be all Â… it isn’t. Those using it need to be careful, check notams, and be prepared for the “RAIM not available” as you get ready to shoot a GPS approach.