Garmin GNC 420W Pilots Guide - Page 203

SECTION 11 ADDITIONAL FEATURES Aural Alerts A TA consists of a displayed traffic symbol (solid yellow circle) and an aural alert. The aural alert announces "traffic", followed by the intruder aircraft's position, altitude relative to own aircraft ("high", "low", or "same altitude"), and distance from own aircraft; e.g. "traffic, 12 o'clock, high, 3 miles". Self-Test The GTS 8XX automatically performs a self-test upon power up. The self-test checks internal parameters and calibrates components of the GTS 8XX. The self-test can also be initiated by the user during normal operation. Check for the following test criteria on the Traffic Page during power-up: • If the GTS 8XX passes the power-up test; and the aircraft both has a squat switch and is on the ground, the Standby Screen is displayed (Figure 11-21). • If the GTS 8XX passes the power-up test and the aircraft both has a squat switch and is airborne, the Traffic Page is displayed on the 6-nm display range and in the normal altitude display mode. • If the GTS 8XX passes the power-up test and the aircraft does not have a squat switch, the Standby Screen is displayed (Figure 11-21). • If the GTS 8XX fails the power-up test (as indicated by a FAILED screen), the GTS 8XX is inoperable, see the GTS 8XX Installation Manual for detailed information on Failure Response. NOTE: The FAILED message is displayed when the system detects an error that prohibits further traffic display operation. NOTE: When the system is in standby, the GTS 8XX does not transmit, interrogate, or track intruder aircraft. Figure 11-21 Standby Mode User-initiated Test In addition to the power-up test, the GTS 8XX performs self-tests during normal operation. A self-test is performed once per minute to verify that the antenna is connected. Also, a calibration is performed at varying intervals based on time and temperature. A user-initiated test of the GTS 8XX interface can also be performed. The test criteria are identical to the power up self-test, although the userinitiated test is concluded by an aural pass/fail message. NOTE: A user-initiated test can only be performed when in standby or failed mode. Performing a user-initiated test: 1) Turn the small right knob to select the Traffic Page. 2) From the Traffic Page, press the MENU Key to display the Page Menu. 3) Turn the small right knob to select 'Self Test?'. 4) Press the ENT Key, 'TEST' is displayed. Figure 11-22 Self-Test Mode 190-00140-20 Rev. K GNC 420(A) Pilot's Guide and Reference 11-13