MD-82
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Landed in Emergency Condition; General Declared Emergency; General Maintenance Action
Aircraft
In cruise; about 40 minutes from landing; the First Officer noted the right hydraulic quantity going to zero. We followed the QRH procedures; declared an emergency; advised Dispatch; talked to Maintenance Control and briefed the flight attendants. We selected the longest runway for landing; successfully accomplished the emergency gear extension procedure; landed; stopped on the runway; had the gear pinned and were towed to the ramp. We landed at about 120;000 pounds.
Less than an hour before landing the flight crew of a MD-82 lost the right hydraulic system due to loss of fluid.  They followed appropriate procedures; landed safely at their destination and were towed to the gate.