Central Mountain D328 near Calgary on Feb 20th 2014, multiple system failure messages

A Central Mountain Air Dornier Do-328-100, registration C-FHVX performing flight 9M-792 from Edmonton,AB to Calgary,AB (Canada) with 24 people on board, was enroute at 10,000 feet when the crew received a "MC R ALT FAIL" message and worked the related checklist without being able to resolve the problem. The crew declared emergency because of an electrical failure. Multiple other system failure messages followed including nose wheel steering, Anti Skid, Flap Asymmetry, Main Hyd pump Inop. A number of aircraft were pulled off the approach to Calgary to permit the Dornier land as quickly as possible. On final approach the crew also reported a hydraulic failure. The aircraft landed safely and vacated the runway on own power.

The Canadian TSB reported that maintenance found a frozen AC hydraulic pump relay, which induced heavy load on the AC alternator causing the AC hydraulic pump to kick off due to continuous load operation. Once the system was reset and the aircraft was powered properly again all systems functioned normally.