While lining up for take-off; the crew of a dhc-8-102 noticed warning indications alerting them to a...

Narrative:

After receiving clearance to takeoff; we were taxiing into position and the first officer completed the before takeoff checklist below the line. As he was finishing the control check and I was lining up with the runway; the #1 'hyd iso' bulb caution light and the 'roll splr' HUD caution lights came on. We looked at the hydraulic gauges and the quantity of #1 was showing below 1 quart. We contacted tower and said we were taxiing off the runway for maintenance. I brought the plane to a stop on the taxiway; stopped the plane and ran the checklist. I also called our dispatcher and spoke to maintenance. We determined we needed to get towed back to the gate; so I taxied the aircraft onto the ramp to expedite that process. Once at the gate maintenance determined that the plane needed to be ferried; and we were swapped onto another aircraft to finish the flight. The inboard hydraulic actuator failed and was leaking; causing the loss of fluid.

Original NASA ASRS Text

Title: While lining up for take-off; the crew of a DHC-8-102 noticed warning indications alerting them to a hydraulic system malfunction. Declining his take-off clearance; the Captain taxied clear of the runway onto the taxiway; and then to the ramp for inspection by Maintenance.

Narrative: After receiving clearance to takeoff; we were taxiing into position and the First Officer completed the Before Takeoff Checklist below the line. As he was finishing the control check and I was lining up with the runway; the #1 'Hyd Iso' bulb caution light and the 'Roll Splr' HUD caution lights came on. We looked at the hydraulic gauges and the quantity of #1 was showing below 1 quart. We contacted Tower and said we were taxiing off the runway for maintenance. I brought the plane to a stop on the taxiway; stopped the plane and ran the checklist. I also called our Dispatcher and spoke to Maintenance. We determined we needed to get towed back to the gate; so I taxied the aircraft onto the ramp to expedite that process. Once at the gate Maintenance determined that the plane needed to be ferried; and we were swapped onto another aircraft to finish the flight. The inboard hydraulic actuator failed and was leaking; causing the loss of fluid.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1082992
Time
Date	201304
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	Dash 8-100
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Component
Aircraft Component	Hydraulic System
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

While lining up for take-off; the crew of a dhc-8-102 noticed warning indications alerting them to a hydraulic system malfunction. Declining his take-off clearance; the captain taxied clear of the runway onto the taxiway; and then to the ramp for inspection by maintenance.