Narrative:

While en route from bos to phl we were given a clearance to cross 50 mi southwest of the hto VOR at FL200. At the time we were level at our cruising altitude just southwest of hto on J121. The aft we were flying is brand new to our company, and is one of the new generation aircraft with a full glass cockpit, dual flight management computers, 2 IRS systems, etc. The aircraft is also new to me, so I would like to think that I am being extra careful and deliberate as I input information. After input and double=checking that I had properly placed the crossing restriction in the FMC, the system displayed an immediate descent prompt. This prompt is used if the crew should decide to initiate the descent prior to the computed descent point. When activated it initiates a 1000 FPM descent until it intercepts the computed descent path. I selected this option and observed on the flight mode annunciator that a descent was annunciated and an altitude (20000') was armed for capture. At this point I then focused my attention on the FMC to adjust the descent rate and to observe the distance to the bottom of the descent point. The captain then said, 'what's going on?', at which point the aircraft was observed 300' high; it had entered a subtle climb seemingly on its own accord. I then disconnected the autoplt and hand flew the aircraft to FL200 and the crossing restriction. While arresting the climb our altitude peaked at 400' above our assigned cruise altitude. This is another case of learning to type 80 words a minute instead of flying the aircraft. In this particular situation, all of this automation took me, the PF, out of the loop as I relied on the aircraft to execute the descent west/O so much as monitoring the aircraft's initial entry into the descent. Also, since the lower altitude was already selected in the flight mode panel, when the aircraft climbed, no altitude warning sounded. If the system is reprogrammed to still sound an alert if the aircraft does not change its flight path in the direction of the armed altitude this problem could have been averted and I would have caught my mistake earlier. Lastly, if the PF still remembers that no matter how much automation there is, the basics still (always) apply. Fly the aircraft from the moment it leaves the gate until it is parked once again at the gate. Don't become passive and let the aircraft fly you. The more automation there is in the aircraft, just means the flight crew should work that much harder to remain an active and integral part of the loop.

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Original NASA ASRS Text

Title: ADVANCED COCKPIT ACR MG EXPERIENCES 400' ALT EXCURSION.

Narrative: WHILE ENRTE FROM BOS TO PHL WE WERE GIVEN A CLRNC TO CROSS 50 MI SW OF THE HTO VOR AT FL200. AT THE TIME WE WERE LEVEL AT OUR CRUISING ALT JUST SW OF HTO ON J121. THE AFT WE WERE FLYING IS BRAND NEW TO OUR COMPANY, AND IS ONE OF THE NEW GENERATION ACFT WITH A FULL GLASS COCKPIT, DUAL FLT MGMNT COMPUTERS, 2 IRS SYSTEMS, ETC. THE ACFT IS ALSO NEW TO ME, SO I WOULD LIKE TO THINK THAT I AM BEING EXTRA CAREFUL AND DELIBERATE AS I INPUT INFO. AFTER INPUT AND DOUBLE=CHKING THAT I HAD PROPERLY PLACED THE XING RESTRICTION IN THE FMC, THE SYS DISPLAYED AN IMMEDIATE DSNT PROMPT. THIS PROMPT IS USED IF THE CREW SHOULD DECIDE TO INITIATE THE DSNT PRIOR TO THE COMPUTED DSNT POINT. WHEN ACTIVATED IT INITIATES A 1000 FPM DSNT UNTIL IT INTERCEPTS THE COMPUTED DSNT PATH. I SELECTED THIS OPTION AND OBSERVED ON THE FLT MODE ANNUNCIATOR THAT A DSNT WAS ANNUNCIATED AND AN ALT (20000') WAS ARMED FOR CAPTURE. AT THIS POINT I THEN FOCUSED MY ATTN ON THE FMC TO ADJUST THE DSNT RATE AND TO OBSERVE THE DISTANCE TO THE BOTTOM OF THE DSNT POINT. THE CAPT THEN SAID, 'WHAT'S GOING ON?', AT WHICH POINT THE ACFT WAS OBSERVED 300' HIGH; IT HAD ENTERED A SUBTLE CLB SEEMINGLY ON ITS OWN ACCORD. I THEN DISCONNECTED THE AUTOPLT AND HAND FLEW THE ACFT TO FL200 AND THE XING RESTRICTION. WHILE ARRESTING THE CLB OUR ALT PEAKED AT 400' ABOVE OUR ASSIGNED CRUISE ALT. THIS IS ANOTHER CASE OF LEARNING TO TYPE 80 WORDS A MINUTE INSTEAD OF FLYING THE ACFT. IN THIS PARTICULAR SITUATION, ALL OF THIS AUTOMATION TOOK ME, THE PF, OUT OF THE LOOP AS I RELIED ON THE ACFT TO EXECUTE THE DSNT W/O SO MUCH AS MONITORING THE ACFT'S INITIAL ENTRY INTO THE DSNT. ALSO, SINCE THE LOWER ALT WAS ALREADY SELECTED IN THE FLT MODE PANEL, WHEN THE ACFT CLBED, NO ALT WARNING SOUNDED. IF THE SYS IS REPROGRAMMED TO STILL SOUND AN ALERT IF THE ACFT DOES NOT CHANGE ITS FLT PATH IN THE DIRECTION OF THE ARMED ALT THIS PROB COULD HAVE BEEN AVERTED AND I WOULD HAVE CAUGHT MY MISTAKE EARLIER. LASTLY, IF THE PF STILL REMEMBERS THAT NO MATTER HOW MUCH AUTOMATION THERE IS, THE BASICS STILL (ALWAYS) APPLY. FLY THE ACFT FROM THE MOMENT IT LEAVES THE GATE UNTIL IT IS PARKED ONCE AGAIN AT THE GATE. DON'T BECOME PASSIVE AND LET THE ACFT FLY YOU. THE MORE AUTOMATION THERE IS IN THE ACFT, JUST MEANS THE FLT CREW SHOULD WORK THAT MUCH HARDER TO REMAIN AN ACTIVE AND INTEGRAL PART OF THE LOOP.

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.