Garmin GDL 90 Installation Manual

Also see for GDL 90: Installation manual

Post-Installation Configuration & CheckoutGDL 90 Installation Manual 560-1049-00 Rev B 3-13 LIMITATIONS3.1 OPERATIONThe installation of a GDL 90 into an aircraft does not alter the operational approvals previously grantedto that aircraft. Additional operation approvals may require FAA evaluation of all the systems installedin a particular aircraft and is outside the scope of the GDL 90 STC.3.2 INSTALLATIONThe conditions and test required for TSO approval of this article are minimum performance standards. Itis the responsibility of those installing this article either on or within a specific type or class of aircraft todetermine that the aircraft installation conditions are within the TSO standards. TSO articles must haveseparate approval for installation in an aircraft. The article may be installed only if performed under 14CFR Part 43 or the applicable airworthiness requirements.If the aircraft with a GDL 90 installed operates outside the state of Alaska, the system must be configuredto disallow the Capstone squawk code features. This is done by configuring the APM to disableCapstone feature (Section 4.2.1.2). In addition, if installed, the MX20 should also be configured toinhibit the entering of squawk code (The transponder should be the only source to enter squawk code.)The TCAS interface is not currently approved for installation or use. The micro APM shall be configuredwith TCAS not installed.3.2.1 GPS ANTENNAThe GDL 90 is only compatible with the Garmin AT A-33 (590-1104) or A-34 (590-1112) antennas, orthose with equivalent specifications. Refer to section 1.3.7.1 for specifications.Testing has demonstrated GDL 90 compatibility with SatCom installation in the aircraft, if cable loss isas specified Section 2.6.1.3.2.2 UAT ANTENNAThe GDL 90 requires at least one UHF antenna meeting the following specifications:• Standard 50Ω vertically polarized antenna with a VSWR < 1.7:1 at 978 Mhz• TSO-C66, C74, C112 or C154 antennas that also meet the VSWR specificationCAUTIONOperating the GDL 90 with no RF terminations on the Top or Bottom UAT Antennaports can result in equipment damage. Always operate the GDL 90 with the Top andBottom UAT Antenna ports terminated with a VSWR ratio of 3.0:1 or less.3.2.3 ANTENNA INSTALLATION – GENERALAntenna installation in the pressure vessel of pressurized aircraft is beyond the scope of the GDL 90STC. Additional manufacturer's data may be necessary and FAA approval may be required to cover theinstallation of any antenna in the pressure vessel of a pressurized aircraft.