(2012) Service Advisory 1227 Rev A: GTN 625/GTN 635/GTN 650/GTN 725/GTN 750 Utilities Pages

DESCRIPTION

The GTN erroneously accepts blank data entry fields for calculating information displayed on the DALT/TAS/Winds Utility Page. To ensure proper information is calculated: all data must be entered on the page and calculations must be verified as reasonable, prior to use.

Flight plans with certain leg types, normally included in approaches, can result in erroneous information on the Fuel Planning Utility Page. There are rare cases when certain approaches loaded in the flight plan can cause the Fuel Required field to be zero.

PRODUCTS AFFECTED

GTN 7XX and 6XX Units with Main Software Version 2.00 and 3.00.

PILOT ACTION

The pilot must verify that all input data has been entered in the DALT/TAS/Winds Utility Page to ensure valid calculations, as stated in section 2.17 “Flight Planner/Calculator Functions” of the current AFMS, (Garmin P/N 190-01007-A2 Rev. 1):

When using the calculator/planner pages, data must be entered into all data fields and verified by the pilot prior to use of the data. Depending on system configuration, the “Use Sensor Data” button may populate the Indicated ALT window with indicated altitude or pressure altitude. The pilot must verify the desired altitude and appropriate barometric pressure setting to ensure valid calculations. Aircraft performance or fuel loading must not be predicated upon the use of data derived from these functions.

If zero fuel required is calculated on the Fuel Planning Utility Page, that feature should not be used for the entered flight plan and loaded procedures.

RESOLUTION

Garmin plans to correct this issue in a future software release.