Narrative:

Add yet another altitude deviation to the ten/eleven thousand problem. I was PF and was given a crossing restriction to cross buzzy intersection at 11000' (STAR had this crossing published as an expected clearance). I was given this altitude crossing with ample time (40 NM to lose, I believe, 10000'). For whatever reason, I elected to start the descent late. To make the crossing properly, without using speed brakes, I made a high-speed descent 340-350 KTS, descent rate 3-4000 FPM. Because of the extremely high rate of descent intentionally held to the last minute, I was mentally focused on arresting the descent smoothly and precisely. Somehow, I had 10000' in my head despite the fact that 11000' was set in the altitude alert. I made a beautiful and precise crossing with 1 mi to spare. Problem was it was at exactly 10000. I assume that because of high descent rate the controller's mode C data was frozen out by the computer. Probably 30 seconds after level at 10, raleigh approach controller questioned our altitude, shortly thereafter he told us to maintain 10. Captain was tuning a navigation radio and identifying station, engineer was copying ATIS and preparing landing data. Cause of the bust, essentially, was that I exceeded the constraints of the safeguards in place to prevent such an incident. Company policy and good airmanship dictate not exceeding 1000 FPM descent for last 1000' of level off. Had I observed this basic rule, the positional awareness I normally have would have been effective. As a side note: I was very fatigued from little sleep the night before. Also, the intersection formation (20 DME) possibly caused a mental suggestion of zero (10000 digits) which, under high workloads, exacerbated the 10/11000' mental mistake.

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Original NASA ASRS Text

Title: FO FLYING AN ACR LGT DURING ARR INTO RDU DESCENDED BELOW CROSSING RESTRICTION ALT OF 11000' BECAUSE HE THOUGHT CLRNC WAS TO 10000'.

Narrative: ADD YET ANOTHER ALT DEVIATION TO THE TEN/ELEVEN THOUSAND PROBLEM. I WAS PF AND WAS GIVEN A XING RESTRICTION TO CROSS BUZZY INTXN AT 11000' (STAR HAD THIS XING PUBLISHED AS AN EXPECTED CLRNC). I WAS GIVEN THIS ALT XING WITH AMPLE TIME (40 NM TO LOSE, I BELIEVE, 10000'). FOR WHATEVER REASON, I ELECTED TO START THE DSCNT LATE. TO MAKE THE XING PROPERLY, WITHOUT USING SPEED BRAKES, I MADE A HIGH-SPEED DSCNT 340-350 KTS, DSCNT RATE 3-4000 FPM. BECAUSE OF THE EXTREMELY HIGH RATE OF DSCNT INTENTIONALLY HELD TO THE LAST MINUTE, I WAS MENTALLY FOCUSED ON ARRESTING THE DSCNT SMOOTHLY AND PRECISELY. SOMEHOW, I HAD 10000' IN MY HEAD DESPITE THE FACT THAT 11000' WAS SET IN THE ALT ALERT. I MADE A BEAUTIFUL AND PRECISE XING WITH 1 MI TO SPARE. PROBLEM WAS IT WAS AT EXACTLY 10000. I ASSUME THAT BECAUSE OF HIGH DSCNT RATE THE CTLR'S MODE C DATA WAS FROZEN OUT BY THE COMPUTER. PROBABLY 30 SECONDS AFTER LEVEL AT 10, RALEIGH APCH CTLR QUESTIONED OUR ALT, SHORTLY THEREAFTER HE TOLD US TO MAINTAIN 10. CAPT WAS TUNING A NAV RADIO AND IDENTIFYING STATION, ENGINEER WAS COPYING ATIS AND PREPARING LNDG DATA. CAUSE OF THE BUST, ESSENTIALLY, WAS THAT I EXCEEDED THE CONSTRAINTS OF THE SAFEGUARDS IN PLACE TO PREVENT SUCH AN INCIDENT. COMPANY POLICY AND GOOD AIRMANSHIP DICTATE NOT EXCEEDING 1000 FPM DSCNT FOR LAST 1000' OF LEVEL OFF. HAD I OBSERVED THIS BASIC RULE, THE POSITIONAL AWARENESS I NORMALLY HAVE WOULD HAVE BEEN EFFECTIVE. AS A SIDE NOTE: I WAS VERY FATIGUED FROM LITTLE SLEEP THE NIGHT BEFORE. ALSO, THE INTXN FORMATION (20 DME) POSSIBLY CAUSED A MENTAL SUGGESTION OF ZERO (10000 DIGITS) WHICH, UNDER HIGH WORKLOADS, EXACERBATED THE 10/11000' MENTAL MISTAKE.

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.