EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
Enroute at cruise altitude; we got a caution message for Hydraulic 1 low quantity followed by Hydraulic 1 low pressure. We confirmed hydraulic fluid lost from hydraulic system page on MFD. Entire fluid leaked within 90 sec. After performing the QRH procedure and talking to Maintenance; we confirmed that complete Hydraulic 1 system lost.  We declared an emergency got out of RVSM and hand flew the airplane as directed by QRH. Performance calculation from QRH required longer finals and longer runway since braking was now reduced to 50% with only one thrust reverser available and multifunction spoilers compromised. After discussing with Company we were directed to change our destination to ZZZ. Passengers and cabin crew were briefed and informed regarding the plan. Airplane flew fine minus the speed brakes. After landing the wheel brakes were sluggish but deceleration was positive. After clearing the runway we had Fire and Rescue give us a visual inspection for any active leaks or smoke. Once cleared and all okay from Fire and Rescue we decided to be towed back to the gate; since brakes were getting hotter by the minute. Passengers were given a bus ride. Except for Hydraulic system 1; all other systems worked exceptionally.
EMB-170 captain reports loss of Hydraulic system 1 in cruise due to loss of hydraulic system fluid. Crew diverts to a suitable airport with a long runway due to loss of some systems. A safe landing ensues.