http://www.faa.gov/aircraft/safety/a...a/CE-07-02.pdf

GNS 480 Navigation System

CNX80 Navigation System

Background

Recent Garmin testing of Satellite Initial

Acquisition and Satellite Reacquisition under

high noise and minimum signal conditions has

shown these products may not fully meet TSOC146a

requirements under these specific

conditions. This could result in the possible

loss of satellite acquisition if these specific

conditions were encountered. Although we are

not aware of a service history problem by

operators, this equipment does not comply with

U.S. 14 CFR part 91, SFAR 97 requirements

for TSO-C146a equipment under minimum

signal and maximum interference conditions.

Deviations have been granted to allow

continued use of these systems while Garmin

brings them into complete TSO compliance.