Narrative:

We were given a transition from olympia airport to the grey NDB for approach sequence into tacoma industrial. We were then instructed to hold at the beacon at 4000 ft and our sequence was #2 for approach. We received instructions to descend to what I understood to be 2000 ft which was the initial approach altitude, and read back 2000 ft. Upon reaching 2400 ft on an inbound heading of 347 we were given a vector to 270 and instructions to climb to 4000 ft. We were then instructed to hold again over the beacon, and shortly given approach clearance to the airport. I was instructed to call seattle approach once on the ground. I explained to the supervisor that the controller seemed very busy, and communications were poor. The controller was not coming in real clear over my headsets, and he did not correct the readback. There was an FAA examiner in the copilot's seat and he did not question the descent. I was told that the controller thought IFR separation had been compromised because of 2 aircraft at the same altitude and a report would be filed. The area was very busy with 3 airports within 5 mi of each other, and a restr area which was active. Other contributing factors: fatigue from long flight and poor communications contributed to wrong perception. I was looking at the approach plate when instructed to descend. The initial approach altitude was 2000 ft. Corrective actions: controller load seemed to be too much. An easing of workload could have caught the aircraft descending through assigned altitude sooner. The examiner is there for several reasons, one is to ensure that the pilot's actions are safe, and when in doubt I should have requested clarification from the controller.

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Original NASA ASRS Text

Title: CHARTER FLT WITH FAA INSPECTOR R SEAT HAS ALTDEV.

Narrative: WE WERE GIVEN A TRANSITION FROM OLYMPIA ARPT TO THE GREY NDB FOR APCH SEQUENCE INTO TACOMA INDUSTRIAL. WE WERE THEN INSTRUCTED TO HOLD AT THE BEACON AT 4000 FT AND OUR SEQUENCE WAS #2 FOR APCH. WE RECEIVED INSTRUCTIONS TO DSND TO WHAT I UNDERSTOOD TO BE 2000 FT WHICH WAS THE INITIAL APCH ALT, AND READ BACK 2000 FT. UPON REACHING 2400 FT ON AN INBOUND HDG OF 347 WE WERE GIVEN A VECTOR TO 270 AND INSTRUCTIONS TO CLB TO 4000 FT. WE WERE THEN INSTRUCTED TO HOLD AGAIN OVER THE BEACON, AND SHORTLY GIVEN APCH CLRNC TO THE ARPT. I WAS INSTRUCTED TO CALL SEATTLE APCH ONCE ON THE GND. I EXPLAINED TO THE SUPVR THAT THE CTLR SEEMED VERY BUSY, AND COMS WERE POOR. THE CTLR WAS NOT COMING IN REAL CLR OVER MY HEADSETS, AND HE DID NOT CORRECT THE READBACK. THERE WAS AN FAA EXAMINER IN THE COPLT'S SEAT AND HE DID NOT QUESTION THE DSCNT. I WAS TOLD THAT THE CTLR THOUGHT IFR SEPARATION HAD BEEN COMPROMISED BECAUSE OF 2 ACFT AT THE SAME ALT AND A RPT WOULD BE FILED. THE AREA WAS VERY BUSY WITH 3 ARPTS WITHIN 5 MI OF EACH OTHER, AND A RESTR AREA WHICH WAS ACTIVE. OTHER CONTRIBUTING FACTORS: FATIGUE FROM LONG FLT AND POOR COMS CONTRIBUTED TO WRONG PERCEPTION. I WAS LOOKING AT THE APCH PLATE WHEN INSTRUCTED TO DSND. THE INITIAL APCH ALT WAS 2000 FT. CORRECTIVE ACTIONS: CTLR LOAD SEEMED TO BE TOO MUCH. AN EASING OF WORKLOAD COULD HAVE CAUGHT THE ACFT DSNDING THROUGH ASSIGNED ALT SOONER. THE EXAMINER IS THERE FOR SEVERAL REASONS, ONE IS TO ENSURE THAT THE PLT'S ACTIONS ARE SAFE, AND WHEN IN DOUBT I SHOULD HAVE REQUESTED CLARIFICATION FROM THE CTLR.

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.