DC-10 30
Flight Crew Commercial
Aircraft Equipment Problem Less Severe
General Declared Emergency
Aircraft
Near top of descent we received a Level 1 alert 'Hyd 3 Elev Off'. The Captain noted that Number 3 Hydraulic quantity was slowly decreasing. We reviewed the Hydraulic 3 Fail Checklist just to be prepared in the event of further fluid loss. As a precaution; we declared an emergency and provided Approach Control with the requested information. The quantity continued to decrease and we decided to lower the gear around 20 miles out to prevent us from needing to use the alternate gear extension. At around 15 miles out we received 'Hyd 3 quant low'. The Captain flew a visual approach without further incident. Upon landing we elected to make a left turn as we had discussed due to possible limitations with the aircraft's ability to turn right. Once clear of the runway; we coordinated with Ground Control and told them we were capable of taxiing to the gate on our own. While taxiing in; we received 'Hyd 3 Fail'. We were able to taxi without incident to our assigned gate.
MD-10 First Officer reported loss of fluid in Hydraulic System 3 at top of descent. They declared an emergency and executed a normal landing.