ZZZ Controller described conflict event when traffic at FL430 experienced a pressurization emergency; initiated a descent creating a TCAS RA with traffic below on another sector.
Synopsis
ZZZ Controller described conflict event when traffic at FL430 experienced a pressurization emergency; initiated a descent creating a TCAS RA with traffic below on another sector.
Narrative
Aircraft X level at FL430 requested FL410. I descended the aircraft to FL410. The pilot declared an emergency and requested lower with the latter part of his transmission unreadable. I cleared Aircraft X to FL380 ( the lower vertical limit of my airspace). I issued merging target procedures to Aircraft X for traffic at 2 o'clock; eight miles; southbound; an airbus at FL370. The pilot did not reply. I issued traffic again to Aircraft X and advised the airbus was descending through FL365 and a response came over the frequency 'Blocked'. My radar associate walked over to the Sector 30 and pointed to the data block of Aircraft X; which had been forced onto the Sector 30 and manually coordinated the emergency status of the aircraft and that it was in an emergency descent. Traffic was again issued to Aircraft X for the airbus at FL360 descending and a frequency change to Sector 30 was issued. I issued a traffic alert; 'Traffic right underneath you; an Airbus at FL350'. The pilot then checked on Sector 30's frequency. The traffic for Aircraft X was an A319. Air Carrier Y received a TCAS alert and descended to avoid Aircraft X.
Second reporter narrative
Enroute we got an amber cabin altitude message. We looked over at the cabin rate and differential gauges and they showed an excessive rate of cabin climb. Shortly after we got an amber cabin altitude message. At this point we did our memory items for an emergency descent called ATC to inform them we had a cabin pressurization problem and needed an immediate descent. He first gave us 36;000; but I told him we had and emergency and needed about 10;000 FT. He then cleared us to 36;000 FT. Again I told him we needed 10;000 FT. About this time we were rapidly approaching 36;000 FT and got an TCAS RA. My co-pilot looked out and saw the aircraft but was unable to let me know due to me talking to ATC trying to get a lower altitude. When the co-pilot saw the aircraft he immediately started a altitude reversal and course change; but went through the assigned altitude by several hundred feet. What I don't understand is after we told ATC we had an emergency why he did not immediately turn the other aircraft away from us. We had an emergency descent going and a rapidly decompressing cabin. That is not a situation for us to be trying to level off at altitude. When we finally got a clearance to about 16;000 FT I asked for the closest airport. ATC suggested an airport but when I realized it was in the mountains and we could not get down to 10;000 FT I asked for an airport behind us that was in open country. They turned us 180 degrees; gave us 90;000 FT. During the descent I did the checklist and the rest of the flight was basically uneventful.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.