The flight crew initiated an emergency return to an Irish airport after the Gulfstream IV-SP’s windshield cracked on takeoff in instrument meteorological conditions. The aircraft was outside the localizer coverage area when the crew armed the autopilot approach mode. As a result, the autopilot captured a false localizer signal. The crew then deviated from the instructions they had received from air traffic control (ATC) and initiated a rapid descent while tracking the false signal. The aircraft was 702 ft above the ground and headed toward the highest mountains in the country when the crew responded to warnings from ATC and from the on-board enhanced ground-proximity warning system (EGPWS).
After climbing — and experiencing further navigational difficulties — the crew landed the GIV. Neither the pilots nor their lone passenger was injured, but damage to the aircraft was substantial, not only from the cracked windshield but from foreign object damage to the no. 1 engine that like…
