EMB ERJ 145 ER/LR
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Aircraft
EICAS message HYDR1 LO QTY popped up. Viewed hydraulics page to monitor fluid quantity and; after consulting QRH; continued toward [destination]. Quantity seemed to be slowly depleting. Hard to tell because the amber portion of the tape is quite small. Took a picture of it to compare. Read and discussed HYDR SYS 1 FAILURE procedure from QRH with First Officer. Sent ACARS messages to Maintenance and Dispatch. Dispatch suggested [an alternate airport] as a diversion airport if needed. After a few minutes [we were] able to positively identify a drop in hydraulic quantity. [We decided to divert to the alternate]. Prepared to land normally but also briefed what we would do if hydraulic system 1 failed. Briefed FA on situation; again; planned a normal landing but prepared to do more. Normal landing. Explained to passengers what we were doing and deplaned. Got some maintenance. Apparently a 'b nut' had come unsecured and backed off; resulting in fluid leakage. Several threats on this one. Bad weather. Last leg. Lots of squinting at a small gauge wondering if I was crazy or if the indicator was in fact slowly moving to the left. Think it went pretty well. Good support from Dispatch; ATC and Ops.
EMB-145XR Captain reported diverting to an alternate airport after experiencing fluid loss in the #1 hydraulic system.