Narrative:

In regular cruise flight at 13;000 feet; the right hydraulic fail annunciator began to occasionally illuminate. After about 2 minutes it illuminated fully. Hydraulic pressure was still normal (2;000 psi). The captain advised ATC of the failure and the prediction that there would be no effect on the continuation of the flight or handling. Approximately 2 minutes later; the left hydraulic fail annunciator began to flicker as well. At this time hydraulic pressure began to fluctuate. Within 2 minutes the left hydraulic annunciator was continuously illuminated and the hydraulic pressure gauge was fluctuating around 400-800 psi. At this time; [ATC was advised] and the captain began requesting weather information for the destination and possible alternates.limitations on the aircraft with a full loss of hydraulic fluid included needing a manual landing gear extension; operating with existing flaps and a loss of hydraulic nose wheel steering (NWS). [Destination] was reporting at the time of the incident winds from the north at 3 KTS; visibility of 1.5 NM and ceiling 600 ovc with braking action reported fair. The declared alternate was reporting higher ceilings and visibility (unknown specifics) but 30 knot winds. Given all of the factors; the captain elected to continue to and terminate in [the original destination]. Upon reaching radio range; dispatch was informed of the situation. The decision was to attempt a no NWS taxi to the ramp if braking action permitted; otherwise shutting down on the runway.a consultation was made with dispatch whether the preference was to land on runway 35 for reduced towing distance or on [the other] runway to deliver freight. Due to the low amount of freight onboard; the decision was made to land on runway 35. Reaching 25 NM from the airport; the captain executed a successful gear extension. A non-eventful [approach to] runway 35 and landing was executed with flaps retracted without incident.after landing; it was determined that the surface braking was quite sufficient for a no NWS taxi to the ramp. After shutdown; the chief pilot was consulted to verify no further action was needed before releasing the cargo. A statement was given to an airport operations representative and the aircraft was secured. Maintenance and operations were briefed on the event; the maintenance log was written up appropriately and the event concluded without incident.

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Original NASA ASRS Text

Title: SA-227AC Captain reported loss of hydraulic fluid in cruise flight.

Narrative: In regular cruise flight at 13;000 feet; the right hydraulic fail annunciator began to occasionally illuminate. After about 2 minutes it illuminated fully. Hydraulic pressure was still normal (2;000 PSI). The Captain advised ATC of the failure and the prediction that there would be no effect on the continuation of the flight or handling. Approximately 2 minutes later; the left hydraulic fail annunciator began to flicker as well. At this time hydraulic pressure began to fluctuate. Within 2 minutes the left hydraulic annunciator was continuously illuminated and the hydraulic pressure gauge was fluctuating around 400-800 PSI. At this time; [ATC was advised] and the Captain began requesting weather information for the destination and possible alternates.Limitations on the aircraft with a full loss of hydraulic fluid included needing a manual landing gear extension; operating with existing flaps and a loss of hydraulic Nose Wheel Steering (NWS). [Destination] was reporting at the time of the incident winds from the north at 3 KTS; visibility of 1.5 NM and ceiling 600 OVC with braking action reported fair. The declared alternate was reporting higher ceilings and visibility (unknown specifics) but 30 knot winds. Given all of the factors; the Captain elected to continue to and terminate in [the original destination]. Upon reaching radio range; dispatch was informed of the situation. The decision was to attempt a no NWS taxi to the ramp if braking action permitted; otherwise shutting down on the runway.A consultation was made with dispatch whether the preference was to land on Runway 35 for reduced towing distance or on [the other] runway to deliver freight. Due to the low amount of freight onboard; the decision was made to land on Runway 35. Reaching 25 NM from the airport; the Captain executed a successful gear extension. A non-eventful [approach to] Runway 35 and landing was executed with flaps retracted without incident.After landing; it was determined that the surface braking was quite sufficient for a no NWS taxi to the ramp. After shutdown; the Chief Pilot was consulted to verify no further action was needed before releasing the cargo. A statement was given to an airport operations representative and the aircraft was secured. Maintenance and operations were briefed on the event; the maintenance log was written up appropriately and the event concluded without incident.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.