What is required to upgrade the Garmin GNS-400/500 series GPS units to include WAAS?
There are quite a few changes and issues that need to be addressed in reference to upgrading/modifying a GNS-400/500 series unit to include WAAS capability. It is strongly suggested that you go through an authorized Garmin dealer who has performed this modification/upgrade previously. There are several installation and certification issues including review of the STC approval from Garmin. This STC includes appendices detailing the approved equipment that can be interfaced to the WAAS capable units as well as approved installation diagrams for these interfaces. The upgrade from Garmin is approximately $1500 and includes the necessary updating of the unit, WAAS antenna, and new IFR-W Jeppesen database. The existing GPS antenna is replaced with the WAAS antenna. This WAAS antenna utilizes the same mounting holes however it should be noted that it is physically larger than the original GA-56 GPS antenna that was included with all GNS-400/500 series units. Also, in regards to the antenna in
There are quite a few changes and issues that need to be addressed in reference to upgrading/modifying a GNS-400/500 series unit to include WAAS capability. It is strongly suggested that you go through an authorized Garmin dealer who has performed this modification/upgrade previously. There are several installation and certification issues including review of the STC approval from Garmin. This STC includes appendices detailing the approved equipment that can be interfaced to the WAAS capable units as well as approved installation diagrams for these interfaces. The upgrade from Garmin includes the necessary updating of the unit, WAAS antenna, and new IFR-W Jeppesen database. The existing GPS antenna is replaced with the WAAS antenna. This WAAS antenna utilizes the same mounting holes however it should be noted that it is physically larger than the original GA-56 GPS antenna that was included with all GNS-400/500 series units. Also, in regards to the antenna installation, RG-142B or RG-4
