Narrative:

I believe the root cause of this incident to be the currently unsatisfactory staffing level at coast TRACON. According to a recent lecture by an FAA rep at MCAS el toro during a wing safety stand down, coast TRACON has about 50% of the controllers required. This controller was busy! Add a few equipment problems to a system already overloaded and the probability of hazard detection and elimination drops to zero. Obvious fix? More people, more scopes, better equipment, and all in a timely manner. We were given a des from FL240 to 12000' about 25 mi east of ocn, and when 10 mi east at 12000' we were told by center to switch to coast approach on 380.2. I checked in with information foxtrot at 12000', altimeter setting was 30.09. The controller thanked us for foxtrot and asked our intentions. I replied that we wanted a PAR to a full stop. We were then told to depart ocn heading 260 degrees and des to 10000'. I rogered and began our des to 10000'. The controller seemed to be quite busy and a hurried call was given to des to 9000' and switch 337.2 (frequency possibly could have been 363.8). There was a lot of chatter on the radios and I believe ics may have blocked part of the controller's request for a speed reduction. I had been doing about 330 KIAS in the des, but slowed to 250 KIAS at 10000', so I assumed that was what he wanted, although I wasn't too sure if he was talking to me because there was a tac call sign 2 aircraft behind me and the callsigns were being cut out a bit by the initial microphone click. Also, the controller's radio was coming in a bit broken, which was confirmed because he had to ask the tac call sign 2 aircraft something twice because of the poor transmission quality. When I checked in on frequency at 9000' the controller said I was supposed to be at 10000'. Because he was still coming in broken I told him that and asked what altitude did he want me at, '9000 or 10000'?' he said to maintain 9000'. During this evolution I spotted what appeared to be an air carrier at my 1 O'clock, nose on, and maybe 4 or 5 mi away at about the same altitude, with what appeared to be his landing light on. There wasn't a traffic call, but I thought later that perhaps the controller was trying to use altitude to separate us. A turn to heading 250 was given to me and complied with, although the traffic didn't appear to be a factor to me. The controller did thank someone on VHF though, so I wasn't too sure of what their perception was at the time. The controller sounded extremely busy, and a quick call to des to 7000', then 4000' and a turn to 330 degrees followed. He called me tac call sign 2 also, adding to the confusion, and I think I heard the other aircraft respond with something. He then asked me twice to confirm that I was tac call sign 1 on 337.2, which I did both times. I was handed off to a final controller, who initially also called me tac call sign 2. An uneventful PAR followed, although there were 2 traffic calls near the coastline at 1 O'clock, and I spotted another aircraft at about our 10 O'clock. I mentioned to the radar officer on ics that it was like threading the needle out here tonight. Because of the request to confirm my call sign and frequency, the controller's obviously irritated tone of voice, and the apparent confusion about my assigned altitude, I began to suspect he might consider flight violating me, hence, I decided to make this statement. The radar officer was not certain about the 9000' des request because he had mentally tuned out all the fast and furious chatter, so he also suggested that I make this statement.

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Original NASA ASRS Text

Title: MIL FLT CREW TOOK CLRNC MEANT FOR ANOTHER MIL ACFT AND DESCENDED TO WRONG ALT.

Narrative: I BELIEVE THE ROOT CAUSE OF THIS INCIDENT TO BE THE CURRENTLY UNSATISFACTORY STAFFING LEVEL AT COAST TRACON. ACCORDING TO A RECENT LECTURE BY AN FAA REP AT MCAS EL TORO DURING A WING SAFETY STAND DOWN, COAST TRACON HAS ABOUT 50% OF THE CTLRS REQUIRED. THIS CTLR WAS BUSY! ADD A FEW EQUIP PROBS TO A SYS ALREADY OVERLOADED AND THE PROBABILITY OF HAZARD DETECTION AND ELIMINATION DROPS TO ZERO. OBVIOUS FIX? MORE PEOPLE, MORE SCOPES, BETTER EQUIP, AND ALL IN A TIMELY MANNER. WE WERE GIVEN A DES FROM FL240 TO 12000' ABOUT 25 MI E OF OCN, AND WHEN 10 MI E AT 12000' WE WERE TOLD BY CENTER TO SWITCH TO COAST APCH ON 380.2. I CHKED IN WITH INFO FOXTROT AT 12000', ALTIMETER SETTING WAS 30.09. THE CTLR THANKED US FOR FOXTROT AND ASKED OUR INTENTIONS. I REPLIED THAT WE WANTED A PAR TO A FULL STOP. WE WERE THEN TOLD TO DEPART OCN HDG 260 DEGS AND DES TO 10000'. I ROGERED AND BEGAN OUR DES TO 10000'. THE CTLR SEEMED TO BE QUITE BUSY AND A HURRIED CALL WAS GIVEN TO DES TO 9000' AND SWITCH 337.2 (FREQ POSSIBLY COULD HAVE BEEN 363.8). THERE WAS A LOT OF CHATTER ON THE RADIOS AND I BELIEVE ICS MAY HAVE BLOCKED PART OF THE CTLR'S REQUEST FOR A SPD REDUCTION. I HAD BEEN DOING ABOUT 330 KIAS IN THE DES, BUT SLOWED TO 250 KIAS AT 10000', SO I ASSUMED THAT WAS WHAT HE WANTED, ALTHOUGH I WASN'T TOO SURE IF HE WAS TALKING TO ME BECAUSE THERE WAS A TAC CALL SIGN 2 ACFT BEHIND ME AND THE CALLSIGNS WERE BEING CUT OUT A BIT BY THE INITIAL MIC CLICK. ALSO, THE CTLR'S RADIO WAS COMING IN A BIT BROKEN, WHICH WAS CONFIRMED BECAUSE HE HAD TO ASK THE TAC CALL SIGN 2 ACFT SOMETHING TWICE BECAUSE OF THE POOR XMISSION QUALITY. WHEN I CHKED IN ON FREQ AT 9000' THE CTLR SAID I WAS SUPPOSED TO BE AT 10000'. BECAUSE HE WAS STILL COMING IN BROKEN I TOLD HIM THAT AND ASKED WHAT ALT DID HE WANT ME AT, '9000 OR 10000'?' HE SAID TO MAINTAIN 9000'. DURING THIS EVOLUTION I SPOTTED WHAT APPEARED TO BE AN AIR CARRIER AT MY 1 O'CLOCK, NOSE ON, AND MAYBE 4 OR 5 MI AWAY AT ABOUT THE SAME ALT, WITH WHAT APPEARED TO BE HIS LNDG LIGHT ON. THERE WASN'T A TFC CALL, BUT I THOUGHT LATER THAT PERHAPS THE CTLR WAS TRYING TO USE ALT TO SEPARATE US. A TURN TO HDG 250 WAS GIVEN TO ME AND COMPLIED WITH, ALTHOUGH THE TFC DIDN'T APPEAR TO BE A FACTOR TO ME. THE CTLR DID THANK SOMEONE ON VHF THOUGH, SO I WASN'T TOO SURE OF WHAT THEIR PERCEPTION WAS AT THE TIME. THE CTLR SOUNDED EXTREMELY BUSY, AND A QUICK CALL TO DES TO 7000', THEN 4000' AND A TURN TO 330 DEGS FOLLOWED. HE CALLED ME TAC CALL SIGN 2 ALSO, ADDING TO THE CONFUSION, AND I THINK I HEARD THE OTHER ACFT RESPOND WITH SOMETHING. HE THEN ASKED ME TWICE TO CONFIRM THAT I WAS TAC CALL SIGN 1 ON 337.2, WHICH I DID BOTH TIMES. I WAS HANDED OFF TO A FINAL CTLR, WHO INITIALLY ALSO CALLED ME TAC CALL SIGN 2. AN UNEVENTFUL PAR FOLLOWED, ALTHOUGH THERE WERE 2 TFC CALLS NEAR THE COASTLINE AT 1 O'CLOCK, AND I SPOTTED ANOTHER ACFT AT ABOUT OUR 10 O'CLOCK. I MENTIONED TO THE RADAR OFFICER ON ICS THAT IT WAS LIKE THREADING THE NEEDLE OUT HERE TONIGHT. BECAUSE OF THE REQUEST TO CONFIRM MY CALL SIGN AND FREQ, THE CTLR'S OBVIOUSLY IRRITATED TONE OF VOICE, AND THE APPARENT CONFUSION ABOUT MY ASSIGNED ALT, I BEGAN TO SUSPECT HE MIGHT CONSIDER FLT VIOLATING ME, HENCE, I DECIDED TO MAKE THIS STATEMENT. THE RADAR OFFICER WAS NOT CERTAIN ABOUT THE 9000' DES REQUEST BECAUSE HE HAD MENTALLY TUNED OUT ALL THE FAST AND FURIOUS CHATTER, SO HE ALSO SUGGESTED THAT I MAKE THIS STATEMENT.

Data retrieved from NASA's ASRS site as of August 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.