A SMT PLT UNFAMILIAR WITH HIS ACFT'S NAV SYS DEVIATED FROM HIS ATC CLRNC.

Date: 2001-08 · Aircraft: Medium Transport; Low Wing; 2 Turbojet Eng · Phase: climb

Anomalies: deviation-altitude-excursion-from-assigned-altitude|deviation-track-heading-all-types|deviation-discrepancy-procedural-clearance

Synopsis

A SMT PLT UNFAMILIAR WITH HIS ACFT'S NAV SYS DEVIATED FROM HIS ATC CLRNC.

Narrative

THE ACFT HAD THE NAV/COM REPLACED WITH THE GARMEN GNS430. THE NEW AUTOMATION INDUCED A CHAIN OF EVENTS THAT LED TO POSSIBLE AIRSPACE COMPROMISE. THE CLRNC WAS FROM GJT TO 1V5 VIA THE GJT 3 DEP DIRECT TO DBL; THEN AS FILED (DIRECT BJC; THEN DIRECT 1V5); MAINTAIN 14000 FT AND EXPECT FL230 IN 10 MINS. THERE WAS SOME CONFUSION WITH THE DEP PROC BECAUSE THE BOOKLET FELL TO THE FLOOR ON TKOF; BUT THE ISSUE SOON RESOLVED ITSELF WITH ALT. WHILE I WAS CLBING TO 14000 FT AND IN CLOUD (APCH HANDED ME OFF TO CTR) I XMITTED; BUT HAD NO ACKNOWLEDGEMENT. I TRIED TO RECONTACT APCH; BUT INSTEAD CYCLED NAV DIGITS AND LOST NAV INDICATIONS. CTR MAY OR MAY NOT HAVE ISSUED FURTHER CLB CLRNC. I LEVELED BRIEFLY AT 14000 FT; BUT REALIZED I WAS NOT ESTABLISHED ON THE AIRWAY AND WAS HEADED INTO AREAS OF 14000 FT MOUNTAINS WITHOUT NAV INDICATION. I ELECTED TO CONTINUE THE CLB. IN A FEW MINS; I CONTACTED (WEAK AND GARBLED) CTR (THEY REVISED CLRNC LIMIT TO FL210) AND RE-ESTABLISHED NAV. LATER; I WAS CLRED DIRECTLY TO 1V5. I TRIED TO ENTER THE DEST INTO THE GNS430; BUT EACH TIME CHARACTERS DISAPPEARED WHENEVER I TRIED TO ENTER DEST. I DISCOVERED AFTERWARD THAT THIS SYS USES THE 'D>' KEY TO INITIATE THE DIRECT TO DEST ENTRY SEQUENCE; WHILE OTHER SYS USE THE 'D>' KEY TO TERMINATE THAT SEQUENCE! THESE DETAILS ARE UNIMPORTANT EXCEPT TO ILLUSTRATE THAT POOR AND INCONSISTENT AUTOMATION DESIGN CAN RESULT IN COCKPIT PANDEMONIUM. WHAT IS IMPORTANT IS THAT NO AUTOMATION SHOULD BE CERTIFICATED INTO A FLT COCKPIT UNLESS BASIC FUNCTIONALITY IS CONTINUOUSLY ASSURED. THAT WAY; A PLT'S INSTRUCTION BOOK IS NOT A REQUIRED COMPONENT OF THE AUTOMATION.

Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.