Narrative:

I was working the right side on sector 24 when aircraft X (a learjet 35/left) at FL390 [requested priority handling]. He said 'we are [requesting priority handling]; we are going down; and we lost pressurization.' I immediately issued him a descent clearance to FL360 the bottom of my stratum and began coordinating. There was traffic in sector 23 at FL350. I called traffic to aircraft X for aircraft Y at FL350 who was already on a vector for traffic in sector 23. I also told him the aircraft at FL350 was turning out of his way; which sector 23 was doing. The sector 23 controller called traffic alerts to multiple aircraft and also turned airplanes out of his way. At the time the [pilot requested priority handling] I had no d-side; but I got one immediately who helped coordinate with sector 68 as well since we didn't know how low he was descending.after aircraft X [requested priority handling] we were unable to communicate with him to see what his intentions were and how low he needed to go. I think he may have messed up his headset when he put on his oxygen because I could hear him keying up with static; but no sound. He also began coast tracking because he tried to enter the emergency code 7700; but typed it in incorrectly. Between not being able to communicate with him and him coast tracking it made it very difficult to guess what he was going to do. He was able to get it to stabilize at FL300. He decided to climb back up to FL330 and continue on [to] his [destination] and cancel his [priority handling]. After reviewing the falcon we lost separation between aircraft X and aircraft Y and had 3.58 miles and 200 feet. I believe this could have been way closer had I not called the traffic at FL350 to aircraft X because it appeared as if he stalled in descent for a few moments while he searched for the traffic.there is no way to prevent these types of emergencies. I think the pilot did what he needed to do as well as all the controllers involved. We really had no time to do anything; but react and call traffic and move anyone who might be in the way. Overall I think we had great teamwork between the controller in charge; pilot; and controllers involved to prevent it from becoming an even more dangerous event.

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Original NASA ASRS Text

Title: Denver Center Controller reported of a loss of separation due to an aircraft losing pressurization and having to descend immediately.

Narrative: I was working the R side on sector 24 when aircraft X (a Learjet 35/L) at FL390 [requested priority handling]. He said 'we are [requesting priority handling]; we are going down; and we lost pressurization.' I immediately issued him a descent clearance to FL360 the bottom of my stratum and began coordinating. There was traffic in sector 23 at FL350. I called traffic to aircraft X for aircraft Y at FL350 who was already on a vector for traffic in sector 23. I also told him the aircraft at FL350 was turning out of his way; which sector 23 was doing. The sector 23 controller called traffic alerts to multiple aircraft and also turned airplanes out of his way. At the time the [pilot requested priority handling] I had no D-side; but I got one immediately who helped coordinate with sector 68 as well since we didn't know how low he was descending.After aircraft X [requested priority handling] we were unable to communicate with him to see what his intentions were and how low he needed to go. I think he may have messed up his headset when he put on his oxygen because I could hear him keying up with static; but no sound. He also began coast tracking because he tried to enter the emergency code 7700; but typed it in incorrectly. Between not being able to communicate with him and him coast tracking it made it very difficult to guess what he was going to do. He was able to get it to stabilize at FL300. He decided to climb back up to FL330 and continue on [to] his [destination] and cancel his [priority handling]. After reviewing the falcon we lost separation between aircraft X and aircraft Y and had 3.58 miles and 200 feet. I believe this could have been way closer had I not called the traffic at FL350 to aircraft X because it appeared as if he stalled in descent for a few moments while he searched for the traffic.There is no way to prevent these types of emergencies. I think the pilot did what he needed to do as well as all the controllers involved. We really had no time to do anything; but react and call traffic and move anyone who might be in the way. Overall I think we had great teamwork between the CIC; pilot; and controllers involved to prevent it from becoming an even more dangerous event.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.