Narrative:

We were flying dfw to iad, and were given a descent crossing shortly after passing beckley VOR. I, the copilot, started a descent to cross putz intersection at the given altitude. I was not certain of the altitude given and glanced at the altitude alert box and saw it was set to FL270. We had been given several step-downs, as usual, and for some reason I thought that the captain had neglected to update the altitude alert. One of the reasons for this is that I had occasionally been setting it myself simply out of convenience to us both since it is on my side. This, I believe was a mistake, which added to the confusion. I then checked the STAR for confirmation, and the STAR said to expect to cross putz at FL240. The captain was listening to the ATIS when I reached up and changed the altitude alert from FL270 to FL240 to agree with the STAR. For confirmation I tapped him on the arm and asked him if it was 240 that we had been cleared to, and he nodded but he was clearly distraction by listening to the ATIS and I'm not sure to this day whether he wasn't just assenting to my question to brush me off so he could listen to the ATIS. It did occur to me to check with ATC, which is my habit in such circumstances, and I frankly do not know why I did not. Perhaps I was distraction by something else. When the plane reached FL250 the controller asked us to check our altitude and said that we had been cleared to FL270 which was initially set on the altitude alert, and not FL240 as I had changed it. The problems I see are my failure to confirm a clearance that I was unsure of. Second, company policy has the pilot receiving the clearance as the one who sets the altitude alert. We were not following this procedure strictly. Third, the captain should not have tried to field my question about a clearance while listening to the ATIS. Finally, clrncs that are other than those published on the plate seem, in retrospect, to have the potential to lead a pilot to follow the published procedure rather than the amendment. Maybe a controller in this case could say, 'cleared to FL270 at putz, contrary to the published altitude.'

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR MLG ALT DEVIATION OVERSHOT DURING DESCENT.

Narrative: WE WERE FLYING DFW TO IAD, AND WERE GIVEN A DSNT XING SHORTLY AFTER PASSING BECKLEY VOR. I, THE COPLT, STARTED A DSNT TO CROSS PUTZ INTXN AT THE GIVEN ALT. I WAS NOT CERTAIN OF THE ALT GIVEN AND GLANCED AT THE ALT ALERT BOX AND SAW IT WAS SET TO FL270. WE HAD BEEN GIVEN SEVERAL STEP-DOWNS, AS USUAL, AND FOR SOME REASON I THOUGHT THAT THE CAPT HAD NEGLECTED TO UPDATE THE ALT ALERT. ONE OF THE REASONS FOR THIS IS THAT I HAD OCCASIONALLY BEEN SETTING IT MYSELF SIMPLY OUT OF CONVENIENCE TO US BOTH SINCE IT IS ON MY SIDE. THIS, I BELIEVE WAS A MISTAKE, WHICH ADDED TO THE CONFUSION. I THEN CHKED THE STAR FOR CONFIRMATION, AND THE STAR SAID TO EXPECT TO CROSS PUTZ AT FL240. THE CAPT WAS LISTENING TO THE ATIS WHEN I REACHED UP AND CHANGED THE ALT ALERT FROM FL270 TO FL240 TO AGREE WITH THE STAR. FOR CONFIRMATION I TAPPED HIM ON THE ARM AND ASKED HIM IF IT WAS 240 THAT WE HAD BEEN CLRED TO, AND HE NODDED BUT HE WAS CLRLY DISTR BY LISTENING TO THE ATIS AND I'M NOT SURE TO THIS DAY WHETHER HE WASN'T JUST ASSENTING TO MY QUESTION TO BRUSH ME OFF SO HE COULD LISTEN TO THE ATIS. IT DID OCCUR TO ME TO CHK WITH ATC, WHICH IS MY HABIT IN SUCH CIRCUMSTANCES, AND I FRANKLY DO NOT KNOW WHY I DID NOT. PERHAPS I WAS DISTR BY SOMETHING ELSE. WHEN THE PLANE REACHED FL250 THE CTLR ASKED US TO CHK OUR ALT AND SAID THAT WE HAD BEEN CLRED TO FL270 WHICH WAS INITIALLY SET ON THE ALT ALERT, AND NOT FL240 AS I HAD CHANGED IT. THE PROBS I SEE ARE MY FAILURE TO CONFIRM A CLRNC THAT I WAS UNSURE OF. SEC, COMPANY POLICY HAS THE PLT RECEIVING THE CLRNC AS THE ONE WHO SETS THE ALT ALERT. WE WERE NOT FOLLOWING THIS PROC STRICTLY. THIRD, THE CAPT SHOULD NOT HAVE TRIED TO FIELD MY QUESTION ABOUT A CLRNC WHILE LISTENING TO THE ATIS. FINALLY, CLRNCS THAT ARE OTHER THAN THOSE PUBLISHED ON THE PLATE SEEM, IN RETROSPECT, TO HAVE THE POTENTIAL TO LEAD A PLT TO FOLLOW THE PUBLISHED PROC RATHER THAN THE AMENDMENT. MAYBE A CTLR IN THIS CASE COULD SAY, 'CLRED TO FL270 AT PUTZ, CONTRARY TO THE PUBLISHED ALT.'

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.