Garmin GDL 69/69A Installation Manual - page 51

Limitations 

GDL 69/69A Installation Manual 

Page 6-1 

190-00355-02  

Revision E 

6 LIMITATIONS 

6.1 Operation 

The installation of a GDL 69/69A into an aircraft does not alter the operation approvals previously 

granted to the aircraft. Additional operation approvals may required FAA evaluation of all systems 

installed in a particular aircraft and is outside the scope of the GDL 69/69A STC. 

Any higher priority audio cautions or alerts, such as the stall warning or gear warning, must disable XM 

audio to crew locations by muting the GDL 69A XM audio with the use of the audio suppression discrete 

inputs on the GDL 69A. 

6.2 Installation 

The GDL 69A XM Satellite Radio audio entertainment may be installed to all passenger locations for all 

aircraft on the STC Approved Model List (AML).  XM audio entertainment to crew locations depends on 

aircraft installation, which must meet requirements of 14 CFR §23.1431(e). 

For purpose of this STC, 14 CFR §23.1431(e) requires that each pilot station must be able to hear the 

aircraft’s stall warning horn with the entertainment system audio set to the maximum pilot controllable 

setting. This also applies to aircraft with a gear extension warning horn.  Aircraft which have electric 

stall/gear warning may utilize the GDL 69A audio suppression input to turn off the music during an 

event. For these installations, the XM audio may be provided to the crew locations. 

For aircraft installations with non-electric stall/gear warning horns, this STC does not provide data for 

installation of audio entertainment to crew locations.  The GDL 69A audio entertainment may not be 

wired to crew locations without a separate evaluation that is beyond the scope of this STC.  It is possible 

for installers to seek evaluation and approval of an alternate installation by means of the field approval 

process.  In both cases, each installation or aircraft type must be evaluated for compliance with 14 CFR 

§23.1431(e).  This evaluation may determine that the required horns can be heard satisfactorily without 

disabling the GDL 69A audio entertainment to the crew. 

NOTE 

For installations with non-electric stall warnings, the installer may attenuate the 

GDL 69A audio provided to crew locations to assist meeting the requirements of 

14 CFR §23.1431(e). The GDL 69A audio output may be attenuated by installing 

series resistors per Figure D-6. 

For preservation of essential equipment in aircraft with multiple power busses, the GDL 69/69A should 

be powered from a non-essential bus. 

6.2.1 Antenna 

The GDL 69/69A is compatible with the Garmin antennas listed in Table 1-5 or those with equivalent 

specifications. Refer to Table 1-7 for specifications. 

6.2.2  Equipment Interfaced to the GDL 69/69A 

Any aircraft systems, other than those shown in this installation manual, that interface to the GDL 69/69A 

are outside the scope of this manual and may require further evaluation and/or certification approval.  

All equipment interfaced to the GDL 69/69A must be previously or concurrently approved. 

6.2.3  Preservation of Previous Systems 

It is the installer’s responsibility to preserve the essential characteristic of the aircraft being modified by 

this manual to be in accordance with the aircraft manufacturer’s original design.  This includes the 

preservation of multiple power buses, which reduce the probability of interrupting power to essential 

instruments and avionics.  The GDL 69/69A is non-essential equipment and as such, if an option to power 

the unit from a non-essential bus is available, it must be used.