Global 5000 (Bombardier)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 150; Flight Crew Total 5800; Flight Crew Type 2850
Fatigue; Situational Awareness
Deviation - Altitude Excursion From Assigned Altitude; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Unstabilized Approach
General None Reported / Taken
Human Factors; Weather
The crew and the aircraft were repositioning after a [trans-Pacific overnight] flight. On arrival the crew was informed they were required to position the aircraft to [another airport]. The weather at [destination] was VMC with no ceiling and excellent visibility with little or no wind. We were given and accepted a visual. Approaching from the northwest we positioned for a left base and configured appropriately; rolling out on final at approximately 1500 ft fully configured with speed reducing as per a normal approach on the visual glide path (one red; one white). Once established on final the crew were distracted by a Cessna given clearance for departure. It was after this that the crew were alerted to an amber windshear annunciation on the primary flight display. As the PIC and the [flying] pilot I elected to continue the visual approach instead of executing an immediate go-around for the windshear. The windshear lasted 15 seconds approximately with minimal airspeed deviation of +/-5 kts.In effort to regain the visual glide path from above after the event a single audible 'sink rate' from the terrain warning system was heard. The aircraft regained the visual glide path at 500 ft and a normal on speed landing ensued. Given the fact the crew had left [departure airport the previous day] and crossed multiple time zones in two days; quality of judgement had been seriously impaired. In hindsight the crew should have stayed in [original destination] and repositioned the aircraft [later]. This would have ensured the crew were well rested and improved judgement and decision making.
Global 5000 Captain reported continuing an approach after receiving a windshear alert. Fatigue following a long duty day of international operations affected his judgment.