Narrative:

We were instructed by ATC to descend from FL240 to FL220 and to begin the descent now. We complied and began an autoplt descent at approximately 800 FPM. No further xmissions were heard from ATC for about 90 seconds. The next transmission we heard was a very frantic controller screaming at an air carrier Y B737 to 'climb immediately. Climb now, climb, climb, climb!' this was immediately followed by a transmission to our aircraft to 'descend now, expedite, expedite, expedite! And turn right to 360 degrees!' we immediately complied although no TCASII warning was received and air carrier Y reported climbing through FL245. It was obvious to us that ATC encountered some sort of transmission problem and may have lost separation. With this in mind, I called the supervisor of the facility upon landing. He explained to me that ATC lost communication with all aircraft on our frequency following a change over to auxiliary power due to bad WX. During the communication loss, our aircraft, air carrier Y and air carrier Z, were all converging. By the time the controller restored communication he was shaken up and attempted not to lose separation by expediting the aircraft involved. According to the ATC supervisor, thanks to the quick response of everyone involved, separation was not lost (although the controller probably lost a few hairs). The moral here is that we all must maintain alertness and vigilance at all times, not just in the terminal area. You never know when a situation like this will occur. It also helps to call ATC afterwards and clarify the situation as well.

Google
 

Original NASA ASRS Text

Title: E120 ACR FLC ISSUED IMMEDIATE ARTCC CTL INSTRUCTIONS TO SEPARATE THE E120 FROM 2 OTHER ACRS. THE PIC WAS ADVISED BY A FACILITY SUPVR THAT THE ARTCC EXPERIENCED COM FAILURE AS FACILITY TRANSITIONED FROM COMMERCIAL TO BACKUP PWR. APPARENTLY, NO LOSS OF SEPARATION OCCURRED.

Narrative: WE WERE INSTRUCTED BY ATC TO DSND FROM FL240 TO FL220 AND TO BEGIN THE DSCNT NOW. WE COMPLIED AND BEGAN AN AUTOPLT DSCNT AT APPROX 800 FPM. NO FURTHER XMISSIONS WERE HEARD FROM ATC FOR ABOUT 90 SECONDS. THE NEXT XMISSION WE HEARD WAS A VERY FRANTIC CTLR SCREAMING AT AN ACR Y B737 TO 'CLB IMMEDIATELY. CLB NOW, CLB, CLB, CLB!' THIS WAS IMMEDIATELY FOLLOWED BY A XMISSION TO OUR ACFT TO 'DSND NOW, EXPEDITE, EXPEDITE, EXPEDITE! AND TURN R TO 360 DEGS!' WE IMMEDIATELY COMPLIED ALTHOUGH NO TCASII WARNING WAS RECEIVED AND ACR Y RPTED CLBING THROUGH FL245. IT WAS OBVIOUS TO US THAT ATC ENCOUNTERED SOME SORT OF XMISSION PROB AND MAY HAVE LOST SEPARATION. WITH THIS IN MIND, I CALLED THE SUPVR OF THE FACILITY UPON LNDG. HE EXPLAINED TO ME THAT ATC LOST COM WITH ALL ACFT ON OUR FREQ FOLLOWING A CHANGE OVER TO AUX PWR DUE TO BAD WX. DURING THE COM LOSS, OUR ACFT, ACR Y AND ACR Z, WERE ALL CONVERGING. BY THE TIME THE CTLR RESTORED COM HE WAS SHAKEN UP AND ATTEMPTED NOT TO LOSE SEPARATION BY EXPEDITING THE ACFT INVOLVED. ACCORDING TO THE ATC SUPVR, THANKS TO THE QUICK RESPONSE OF EVERYONE INVOLVED, SEPARATION WAS NOT LOST (ALTHOUGH THE CTLR PROBABLY LOST A FEW HAIRS). THE MORAL HERE IS THAT WE ALL MUST MAINTAIN ALERTNESS AND VIGILANCE AT ALL TIMES, NOT JUST IN THE TERMINAL AREA. YOU NEVER KNOW WHEN A SIT LIKE THIS WILL OCCUR. IT ALSO HELPS TO CALL ATC AFTERWARDS AND CLARIFY THE SIT AS WELL.

Data retrieved from NASA's ASRS site as of July 2007 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.