Narrative:

We were in a descent for landing at phl. Captain was flying. We were given a clearance to cross 45 east of johnstown at and maintain FL250. We missed our crossing restriction and xed the 45 mi point at 260 in the descent. Reached 250 at 48 mi east of jst. We were given clearance just about the time we would have to start own to make it. I did the mental calculations in my head to determine this and I assume the captain did not. Instead he started to enter the crossing restriction into the FMC so as to let the computer figure it out and to control our descent. After about 30 seconds, it was obvious he was having trouble getting the FMC to accept his instructions. I had already made a comment like 'we'll have to start down now if we're going to make it.' previously, and I again said something like, 'we're going to the point where we're not gonna make it if don't start down now.' he finally stopped to load it into the computer and used the autoplts vertical speed feature to start the aircraft down (manually flight the autoplt). At something like 28000' I said 'I don't think we're going to make it.' his response was 'piece of cake.' at this point I should have suggested letting ATC know we weren't going to make it, but his answer led me to believe that he thought we would, and he would just say 'no'. (We had TCAS on this aircraft and I knew there wasn't a conflict with another aircraft as there was nothing on the screen). As we leveled off we were given a frequency change to my (132.2) and neither controller said anything. (I suspect their computer could not keep up with our rate of descent and was not showing accurate altitude readouts on their screen). Cause. This was the capts first month on the airplane with the FMC. He had previously flown an older version of this aircraft west/O the automated cockpit. Several comments during the trip showed me he was fascinated with all the 'golly gee-whiz' of the FMC. I think he just became too engrossed in having the FMC do it for him instead of figuring it out mentally first and then if there's time, let the FMC do it. Otherwise take it down manually. This is what he didn't do. (I think).

Google
 

Original NASA ASRS Text

Title: ALT CROSSING RESTRICTION MISSED MY 1000'.

Narrative: WE WERE IN A DSNT FOR LNDG AT PHL. CAPT WAS FLYING. WE WERE GIVEN A CLRNC TO CROSS 45 E OF JOHNSTOWN AT AND MAINTAIN FL250. WE MISSED OUR XING RESTRICTION AND XED THE 45 MI POINT AT 260 IN THE DSNT. REACHED 250 AT 48 MI E OF JST. WE WERE GIVEN CLRNC JUST ABOUT THE TIME WE WOULD HAVE TO START OWN TO MAKE IT. I DID THE MENTAL CALCULATIONS IN MY HEAD TO DETERMINE THIS AND I ASSUME THE CAPT DID NOT. INSTEAD HE STARTED TO ENTER THE XING RESTRICTION INTO THE FMC SO AS TO LET THE COMPUTER FIGURE IT OUT AND TO CTL OUR DSNT. AFTER ABOUT 30 SECS, IT WAS OBVIOUS HE WAS HAVING TROUBLE GETTING THE FMC TO ACCEPT HIS INSTRUCTIONS. I HAD ALREADY MADE A COMMENT LIKE 'WE'LL HAVE TO START DOWN NOW IF WE'RE GOING TO MAKE IT.' PREVIOUSLY, AND I AGAIN SAID SOMETHING LIKE, 'WE'RE GOING TO THE POINT WHERE WE'RE NOT GONNA MAKE IT IF DON'T START DOWN NOW.' HE FINALLY STOPPED TO LOAD IT INTO THE COMPUTER AND USED THE AUTOPLTS VERTICAL SPD FEATURE TO START THE ACFT DOWN (MANUALLY FLT THE AUTOPLT). AT SOMETHING LIKE 28000' I SAID 'I DON'T THINK WE'RE GOING TO MAKE IT.' HIS RESPONSE WAS 'PIECE OF CAKE.' AT THIS POINT I SHOULD HAVE SUGGESTED LETTING ATC KNOW WE WEREN'T GOING TO MAKE IT, BUT HIS ANSWER LED ME TO BELIEVE THAT HE THOUGHT WE WOULD, AND HE WOULD JUST SAY 'NO'. (WE HAD TCAS ON THIS ACFT AND I KNEW THERE WASN'T A CONFLICT WITH ANOTHER ACFT AS THERE WAS NOTHING ON THE SCREEN). AS WE LEVELED OFF WE WERE GIVEN A FREQ CHANGE TO MY (132.2) AND NEITHER CTLR SAID ANYTHING. (I SUSPECT THEIR COMPUTER COULD NOT KEEP UP WITH OUR RATE OF DSNT AND WAS NOT SHOWING ACCURATE ALT READOUTS ON THEIR SCREEN). CAUSE. THIS WAS THE CAPTS FIRST MONTH ON THE AIRPLANE WITH THE FMC. HE HAD PREVIOUSLY FLOWN AN OLDER VERSION OF THIS ACFT W/O THE AUTOMATED COCKPIT. SEVERAL COMMENTS DURING THE TRIP SHOWED ME HE WAS FASCINATED WITH ALL THE 'GOLLY GEE-WHIZ' OF THE FMC. I THINK HE JUST BECAME TOO ENGROSSED IN HAVING THE FMC DO IT FOR HIM INSTEAD OF FIGURING IT OUT MENTALLY FIRST AND THEN IF THERE'S TIME, LET THE FMC DO IT. OTHERWISE TAKE IT DOWN MANUALLY. THIS IS WHAT HE DIDN'T DO. (I THINK).

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.