Installation Instructions

190-01007-A3 GTN 6XX/7XX AML STC Installation Manual
Rev. 4 Page B-3
B.2 General Requirements for GTN 6XX/7XX Installations
Figure B-2 illustrates the avionics rack mounting rails and forward rack support required in all
GTN 6XX/7XX installations.
In order to satisfy the structural requirements for the GTN 6XX/7XX the following conditions must be
met:
1. If existing structure is to be used for mounting the GTN 6XX/7XX, it must meet the following
requirements:
a. Sheet aluminum instrument panel structure must be at least 0.062” thick
b. Avionics stack “brackets” or “rails” must be at least 0.032” thick
2. It is acceptable to reuse existing support brackets or plates. Minor modifications can be made to
adjust for the GTN 6XX/7XX mounting rack hole patterns.
a. Maintain an edge distance of at least 2*D (center of hole to edge of part) for all new
holes.
b. Maintain a minimum of 3*D (center to center) for all new holes.
3. If support brackets or plates do not exist, cannot be modified to fit, or otherwise need to be
fabricated for this installation, they should be fabricated and attached to the aircraft instrument
panel structure in accordance with the methods outlined in AC 43.13-2B Chapter 2, AC 43.13-1B
Chapter 4, and the following requirements:
a. Material shall be 2024-T3 sheet aluminum (bare or Clad), minimum of 0.032” thick
b. Use sheet metal techniques (bend radius, fillets, etc.) appropriate to material type and
thickness.
c. Bracket or plate must have a minimum of two fastener holes (6-32 screws) for each
GTN 6XX/7XX mounting rack. Nutplates may be installed on the bracket or plate to secure
the 6-32 screws.
d. Fabricated parts shall be corrosion protected. Apply zinc chromate primer that meets FED
STD TT-P-1757, or epoxy primer that meets MIL-P-23377, or other corrosion protection
methods listed in the aircraft’s maintenance manual.
e. If possible, fabricate and install a support between the mounting tray and a nearby
structural member of the aircraft, as recommended in AC 43.13-2B, Chapter 2.
See Section B.6 for example layouts.