GTN 650Xi satellite-navigation receiver

The GTN 650Xi is a panel-mounted GPS/NAV/COM navigator from Garmin, a touchscreen flight navigator that combines a WAAS/SBAS-capable GPS receiver with a VHF communications radio and a VOR/localizer/glideslope receiver. It is a certified avionics unit for manned aircraft and rotorcraft, and in the category of GPS receivers it acts as the navigation source for the aircraft's flight plan, approach guidance and radio tuning.

The satellite-navigation function follows the GTN 6XX family. Garmin's maintenance manual lists the GTN 625 as a GPS/SBAS navigator conforming to TSO-C146c and says that the GTN 650 includes all the features of the GTN 625, adding an airborne VHF communications transceiver and VOR/LOC and glideslope receivers. The maker's product page adds that the WAAS/SBAS-certified receiver supports GPS-guided LPV approaches with minimums as low as 200 ft, comparable to an ILS.

The display is a 4.9 in touchscreen. Through it the crew reaches navigation functions, radio tuning and multifunction display features. The 6XX family is 6.25 in wide and 2.65 in tall, with a 600 x 266 pixel colour LCD, which defines the panel cut-out and the space needed behind the instrument panel.

Data links extend the unit beyond position and guidance. The product page lists ADS-B traffic and weather, and a Flight Stream 510 wireless data card that synchronises databases with portable electronic devices. Those functions require compatible data-link equipment in the installation.

Integration uses the aircraft's existing avionics. According to the manual, the GTN utilises ARINC 429, RS-232, discrete inputs and outputs, and HSDB interfaces to exchange data with other equipment, such as audio panels, air data computers, altitude encoders, EFIS displays, navigation indicators, transponders and fuel management systems. The 650-class unit has a single navigation antenna port and, where separate VOR/localizer and glideslope antennas are fitted, needs a diplexer to combine them. A GPS/WAAS antenna and a COM antenna are also required.

For certification, the GTN 6XX/7XX documentation covers Part 27 rotorcraft installations under a supplemental type certificate, and GPS/SBAS operation to TSO-C146c is stated for the GPS function.

Typical applications are avionics suites in general aviation aircraft and helicopters, and certified platforms that require IFR GPS navigation, radio communication and approach capability from one unit.