Narrative:

Altitude bust occurred during descent to meet crossing restriction at doccs intersection at 11000' and 250 KTS. Aircraft descended to 10500' before returning to 11000'. I think this was caused by 4 factors: 1) the doccs 4 arrival procedure is poorly designed and always requires high rates of descent to meet the restriction at doccs intersection. The crossing restriction at puttz intersection only allows 51 NM to descent 13000' and slow to 250 KTS. The puttz expect to cross altitude is never issued by ATC usually because of traffic conflicts, and was not issued in this case. We crossed puttz descending at about 27000'. We did start our descent as soon as we were issued a clearance. With tailwinds almost always present, the restriction is hard to meet if you cross puttz at 24000'. You are even farther behind if ATC delays your descent clearance for traffic. These problems also put the aircraft in a high speed high vertical speed condition approaching doccs. 2) doccs uses a non standard level off altitude of 11000'. I'm sure there is an ATC reason for this, such as radar coverage or letters of agreement, but standardization is an important factor in keeping the system safe. Most approach facility gates for the jet dump areas use 10000' as the standard level-off altitude. I knew I was descending to 11000' when I started the descent. The first officer called 12000 for 11000' and the altitude alert went off at 12000', but as I was concentrating on the DME reading my mind went to 10000' as a level-off altitude. Yrs of descending to 10000', I would guess, but that's why it's important to keep these altitudes standard. If I had not been forced into a high speed, high rate descent by the design of the doccs procedure, I would not have had to concentrate on the DME so much that the target altitude slipped from my mind and reverted back to 10000'. Also I could have recognized my mistake at 11000' which I did and recovered with only 200' overshoot instead of 500'. 3) altitude alert window in our aircraft is not visible from left seat at night. It's hard to double-check the altitude set west/O leaving forward and turning up the lights. 4) altitude alert box in our aircraft have trouble with vol setting of alert tone. Always too loud or too soft, never quite right. Also warning light is difficult to adjust for proper illumination at night, either too bright or too dim.

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Original NASA ASRS Text

Title: PLT OF MLG OVERSHOT LEVEL OFF AT DOCCS INTXN AT 11000'. REPORTER COMPLAINS ARR IS POORLY DESIGNED.

Narrative: ALT BUST OCCURRED DURING DSNT TO MEET XING RESTRICTION AT DOCCS INTXN AT 11000' AND 250 KTS. ACFT DSNDED TO 10500' BEFORE RETURNING TO 11000'. I THINK THIS WAS CAUSED BY 4 FACTORS: 1) THE DOCCS 4 ARR PROC IS POORLY DESIGNED AND ALWAYS REQUIRES HIGH RATES OF DSNT TO MEET THE RESTRICTION AT DOCCS INTXN. THE XING RESTRICTION AT PUTTZ INTXN ONLY ALLOWS 51 NM TO DSNT 13000' AND SLOW TO 250 KTS. THE PUTTZ EXPECT TO CROSS ALT IS NEVER ISSUED BY ATC USUALLY BECAUSE OF TFC CONFLICTS, AND WAS NOT ISSUED IN THIS CASE. WE CROSSED PUTTZ DSNDING AT ABOUT 27000'. WE DID START OUR DSNT AS SOON AS WE WERE ISSUED A CLRNC. WITH TAILWINDS ALMOST ALWAYS PRESENT, THE RESTRICTION IS HARD TO MEET IF YOU CROSS PUTTZ AT 24000'. YOU ARE EVEN FARTHER BEHIND IF ATC DELAYS YOUR DSNT CLRNC FOR TFC. THESE PROBS ALSO PUT THE ACFT IN A HIGH SPD HIGH VERT SPD CONDITION APCHING DOCCS. 2) DOCCS USES A NON STANDARD LEVEL OFF ALT OF 11000'. I'M SURE THERE IS AN ATC REASON FOR THIS, SUCH AS RADAR COVERAGE OR LETTERS OF AGREEMENT, BUT STANDARDIZATION IS AN IMPORTANT FACTOR IN KEEPING THE SYS SAFE. MOST APCH FAC GATES FOR THE JET DUMP AREAS USE 10000' AS THE STANDARD LEVEL-OFF ALT. I KNEW I WAS DSNDING TO 11000' WHEN I STARTED THE DSNT. THE F/O CALLED 12000 FOR 11000' AND THE ALT ALERT WENT OFF AT 12000', BUT AS I WAS CONCENTRATING ON THE DME READING MY MIND WENT TO 10000' AS A LEVEL-OFF ALT. YRS OF DSNDING TO 10000', I WOULD GUESS, BUT THAT'S WHY IT'S IMPORTANT TO KEEP THESE ALTS STANDARD. IF I HAD NOT BEEN FORCED INTO A HIGH SPD, HIGH RATE DSNT BY THE DESIGN OF THE DOCCS PROC, I WOULD NOT HAVE HAD TO CONCENTRATE ON THE DME SO MUCH THAT THE TARGET ALT SLIPPED FROM MY MIND AND REVERTED BACK TO 10000'. ALSO I COULD HAVE RECOGNIZED MY MISTAKE AT 11000' WHICH I DID AND RECOVERED WITH ONLY 200' OVERSHOOT INSTEAD OF 500'. 3) ALT ALERT WINDOW IN OUR ACFT IS NOT VISIBLE FROM LEFT SEAT AT NIGHT. IT'S HARD TO DOUBLE-CHK THE ALT SET W/O LEAVING FORWARD AND TURNING UP THE LIGHTS. 4) ALT ALERT BOX IN OUR ACFT HAVE TROUBLE WITH VOL SETTING OF ALERT TONE. ALWAYS TOO LOUD OR TOO SOFT, NEVER QUITE RIGHT. ALSO WARNING LIGHT IS DIFFICULT TO ADJUST FOR PROPER ILLUMINATION AT NIGHT, EITHER TOO BRIGHT OR TOO DIM.

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.