Date: 201701
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: Marginal
Weather elements / visibility: Rain
Aircraft: B757 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Main Gear
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Normal ILS approach. Just prior to the FAF; while I was descending through 2;000 feet; I (PF) called for 'gear down;' before landing checklist. We first noticed a caution message of 'auto speed brakes' followed by the 'GEAR DISAGREE' EICAS. The right main landing gear did not indicate down and locked.Advised the Tower we did not get a right gear down indication and will be executing a missed. We also asked Tower if they could give us an assessment of the right landing gear. Initial missed approach instructions from the Tower were to fly runway heading and climb to 2;000 feet. Tower also advised us that during the climb out they could not see our aircraft to assess whether the gear was down.We then were vectored to a downwind leg and instructed to climb to 5;000 feet. Once we leveled off at 2;000 feet; I turned on the autopilot and told the Captain that I had the radios while he was running the QRH. The Captain then let me know he would be informing the flight attendants and the passengers for the reason of the go around. I continued the climb to 5;000 feet and followed vectors from ATC. When the Captain was back in the QRH; he mentioned how most of the landing gear controls would be on my side of the aircraft and therefore easier for me to run the QRH while he flew so we transferred controls on downwind. Not sure why the gear did not extend or if it would extend and lock down via alternate method; we [requested priority handling] with Tower and told them we may need extra time to complete our checklists and extend the gear. Somewhere in that sequence we noticed the left hydraulic quantity had depleted down to .30 (standpipe). Approach and Tower were very helpful and gave us anything we needed.The Captain flew and communicated with ATC; while I ran the QRH. I coordinated with the Captain and flight attendants to ensure we had completed all the necessary steps for a possible evacuation. I made very clear to all the flight attendants to only prep the cabin for evacuation and not to evacuate unless given the signal. I relayed the vitals to Tower (Souls On Board (SOB); time in fuel; fire trucks standby) and notified the Company of our situation. Time was a bit crunched due to weather and our fuel (9;600 pounds) when we turned for final on the second approach; so we wanted to act very efficiently throughout the process.Tower let us call our base when we were ready. We intercepted a 10 mile ILS final. Extended the gear per the QRH; and completed the checklist. Fully stabilized and established on glideslope; I did a quick review of the non-normal procedure to ensure we did not miss anything. Landed uneventfully. Released the fire trucks. Taxied to gate. After we shutdown; Maintenance met us at the airplane.


Second narrative: Weather: Marginal VFR; 1;000 scattered; 1;500 broken; 10 miles visibility; light drizzle; winds 210 at 11 knots. Normal ILS Approach. Just prior to FAF; while descending through 2;000 the First Officer (PF) called for 'gear down; before landing check.' Both pilots noticed the 'GEAR DISAGREE' EICAS. The right main landing gear did not indicate down and locked. Advised the Tower we did not get a right gear down indication and will be executing a missed. We also asked Tower if they could give us an assessment of the right landing gear. Initial missed approach instructions from the Tower were to fly runway heading and climb to 2;000.Tower also advised us that during the climbout they could not see our aircraft to assess whether the gear was down. Vectored to a downwind leg and instructed to climb to 5;000 feet. Stabilized on downwind; the First Officer put the aircraft on autopilot. We notified the flight attendants of the reason for the go around; and made a quick PA to the passengers.Transferred aircraft control on downwind. Not sure why the gear did not extend or if it would extend and lock down via alternate method; we [requested priority handling] with Tower and told them we may need extra time to complete our checklists and extend the gear. Somewhere in that sequence we noticed the left hydraulic quantity had depleted down to .30 (standpipe). Tower was very; very accommodating. The Captain flew and communicated with ATC; while the First Officer ran the QRH.The First Officer also coordinated with the flight attendants (ensuring they understood we wanted them to prepare the cabin for evacuation). He relayed the vitals to Tower (Souls On Board (SOB); time in fuel; fire trucks standby) and notified the company of our situation. Overall; an excellent job by the First Officer in such a short; compressed time frame. Tower let us call our base when we were ready. We intercepted a 10 mile ILS final. Extended the gear per the QRH; and completed the checklist. Fully stabilized and established on glideslope; the First Officer did a quick review of the non-normal procedure to ensure we did not miss anything. Landed uneventfully. Released the fire trucks. Taxied to gate. After we shutdown; Maintenance met us at the airplane.


Synopsis: B757 flight crew reported the right main landing gear failed to extend and was accompanied by a partial loss of hydraulic fluid. The flight crew executed a go-around and extended the landing gear via the alternate extension method in the QRH.