MD-83
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport
Aircraft
We were on initial climb out of about 2;000 MSL when the L HYD PRESS LOW light came on. As the non-flying pilot; I reached for the QRH to begin working the problem when the light extinguished.Just after the flying pilot called for the slats to be retracted; as I performed my climb flow and turned off the aux hydraulic pump and the hydraulic transfer pump. I noticed that the left hydraulic system had lost pressure and the quantity gauge read just below two quarts. I performed the QRH procedures and we decided the return to our departure airport. We landed normally and taxied to the gate with no further incident. A Contract Mechanic informed us that we had an O-ring on a securing nut fail causing the left hand system to drain almost all of the hydraulic fluid. He then proceeded to get us back airworthy in a very timely manner. I commend First Officer and the flight attendants for their calm and professional demeanor during our event. Positive training; standardization; and CRM were key elements that assured our situation turned out safely.
Shortly after takeoff the flight crew of an MD-83 suffered the loss of the left hydraulic system. They complied with the appropriate checklists and returned safely to their departure airport where Maintenance replaced a broken O-ring on a securing nut which resolved the problem.