Regional Jet 200 ER/LR (CRJ200)
Flight Crew Commercial
Aircraft Equipment Problem Critical
General Declared Emergency; General Maintenance Action
Aircraft
The aircraft had an MEL deferring the hydraulic system one quantity indicators. We complied with the operational procedures with the MEL and I verified the quantity when I did my preflight. While in cruise we received a HYD 1 LOW PRESSURE caution message. The pilot flying took over the radios and I complied with the QRH. The 1A pump was putting out 0 PSI and; with the 1B pump operational; the pressure would fluctuate between 800-1;400 PSI. As per the QRH we needed to land at nearest suitable airport. The pilot flying transferred flight controls and radios to me and I became the pilot flying. He received all appropriate weather and NOTAMS while I communicated with Approach and flew the airplane to get in a position to land. No emergency was declared; however [Tower] had rolled the fire trucks. The landing was made. It was uneventful and once deplaned we contacted Maintenance. The threat was allowing the aircraft to operate under that MEL because once we were in flight we did not know the actual quantity in flight while running the QRH.
A CRJ-200 with deferred system one quantity indicator had low pressure in hydraulic system one in cruise flight. Aircraft continued to destination where a normal landing was made with equipment standing by.