Narrative:

We were cleared to descend from our en route altitude of FL330 to maintain FL210. We were then told to turn 90 degrees off our arrival route to a heading of 220 degrees for traffic and was told to expect direct ramms intersection and the ramms 1 arrival. I programmed the ramms 1 arrival in the FMC which was ramms 250 KTS at or below 17000 ft. We were then cleared to ramms and the ramms 1 arrival. There was some question between the captain and I about which altitude we should descend to. In hindsight, looking back, it was so plain and simple to just maintain our last assigned altitude of FL210. However, maybe because of such a short rest period prior, we both convinced ourselves 17000 ft was a hard altitude and set 17000 ft in the mode control panel. Instead of asking the controller what altitude we were cleared to, I just asked center twice if he would confirm that we were cleared the ramms 1 arrival and he acknowledged. I believe the word 'expect' on the arrival should be in larger, bolder letters. Also, for us twilight flying crews, if ATC would only reinstate an altitude in a new clearance. Example: (flight XXX you are now cleared to direct ramms, the ramms 1 arrival, maintain FL210 normal speed, etc). Supplemental information from acn 301912: the first officer put 17000 ft in the mode control panel. I selected flight level change and we descended to 17000 ft. At ramms, the controller asked if he had cleared us to 17000 ft on the ramms arrival. We replied, no, the ramms arrival. He advised that this is just routing and not a clearance to descend, then gave us the frequency change to den approach. In retrospect and after reviewing the arrival, it was clear to me that this was not a profile descent and again I'm not sure why I confused it with one. I can only suggest that for those times when we are flying fatigued or become distracted by other matters the wording for these type of arrs might be changed to read: expect 250 KTS, and expect 17000 ft or below.'

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Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION DURING A NON ADHERENCE TO ATC PROC CLRNC INSTRUCTION.

Narrative: WE WERE CLRED TO DSND FROM OUR ENRTE ALT OF FL330 TO MAINTAIN FL210. WE WERE THEN TOLD TO TURN 90 DEGS OFF OUR ARR RTE TO A HDG OF 220 DEGS FOR TFC AND WAS TOLD TO EXPECT DIRECT RAMMS INTXN AND THE RAMMS 1 ARR. I PROGRAMMED THE RAMMS 1 ARR IN THE FMC WHICH WAS RAMMS 250 KTS AT OR BELOW 17000 FT. WE WERE THEN CLRED TO RAMMS AND THE RAMMS 1 ARR. THERE WAS SOME QUESTION BTWN THE CAPT AND I ABOUT WHICH ALT WE SHOULD DSND TO. IN HINDSIGHT, LOOKING BACK, IT WAS SO PLAIN AND SIMPLE TO JUST MAINTAIN OUR LAST ASSIGNED ALT OF FL210. HOWEVER, MAYBE BECAUSE OF SUCH A SHORT REST PERIOD PRIOR, WE BOTH CONVINCED OURSELVES 17000 FT WAS A HARD ALT AND SET 17000 FT IN THE MODE CTL PANEL. INSTEAD OF ASKING THE CTLR WHAT ALT WE WERE CLRED TO, I JUST ASKED CTR TWICE IF HE WOULD CONFIRM THAT WE WERE CLRED THE RAMMS 1 ARR AND HE ACKNOWLEDGED. I BELIEVE THE WORD 'EXPECT' ON THE ARR SHOULD BE IN LARGER, BOLDER LETTERS. ALSO, FOR US TWILIGHT FLYING CREWS, IF ATC WOULD ONLY REINSTATE AN ALT IN A NEW CLRNC. EXAMPLE: (FLT XXX YOU ARE NOW CLRED TO DIRECT RAMMS, THE RAMMS 1 ARR, MAINTAIN FL210 NORMAL SPD, ETC). SUPPLEMENTAL INFO FROM ACN 301912: THE FO PUT 17000 FT IN THE MODE CTL PANEL. I SELECTED FLT LEVEL CHANGE AND WE DSNDED TO 17000 FT. AT RAMMS, THE CTLR ASKED IF HE HAD CLRED US TO 17000 FT ON THE RAMMS ARR. WE REPLIED, NO, THE RAMMS ARR. HE ADVISED THAT THIS IS JUST ROUTING AND NOT A CLRNC TO DSND, THEN GAVE US THE FREQ CHANGE TO DEN APCH. IN RETROSPECT AND AFTER REVIEWING THE ARR, IT WAS CLR TO ME THAT THIS WAS NOT A PROFILE DSCNT AND AGAIN I'M NOT SURE WHY I CONFUSED IT WITH ONE. I CAN ONLY SUGGEST THAT FOR THOSE TIMES WHEN WE ARE FLYING FATIGUED OR BECOME DISTRACTED BY OTHER MATTERS THE WORDING FOR THESE TYPE OF ARRS MIGHT BE CHANGED TO READ: EXPECT 250 KTS, AND EXPECT 17000 FT OR BELOW.'

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.