A B777 crew, descending into ewr, undershot assigned altitude.

Attributes
ACN	547043
Time
Date	200205
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : sax.vortac
State Reference	NJ
Altitude	msl single value : 8300
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw.artcc
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 115 flight time total : 19500 flight time type : 600
ASRS Report	547043
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	altitude deviation : undershoot altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : overrode automation none taken : unable
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During a descent to ewr, ZBW issued us a clearance to cross 20 mi north of sax VOR. The first officer was flying the aircraft and he programmed the FMC to cross 20 mi north of sax as cleared. The first officer chose to use the VNAV feature to comply with the clearance. We left 16000 ft and the VNAV feature appeared to do what it was designed to do. During the descent, I noticed that the 'math' didn't compute to meet the crossing restr. I then suggested to use the speed brakes to expedite the descent and to decelerate to 250 KTS prior to passing 10000 ft. First officer protested by saying, 'the machine will do it.' when it became obvious that the rate of descent would not comply with the crossing clearance, first officer became fixated as to why the VNAV feature did not work as programmed. At this point, I fully extended the speed brake to increase the rate of descent and descend to our assigned altitude as rapidly as possible. It is painfully obvious that too much emphasis is being placed in the automation and the basics of flying an aircraft are being abandoned. The concept of automation should be considered as an aid instead of the principal mode of safely operating an aircraft. Common sense is rapidly dwindling.

Original NASA ASRS Text

Title: A B777 CREW, DSNDING INTO EWR, UNDERSHOT ASSIGNED ALT.

Narrative: DURING A DSCNT TO EWR, ZBW ISSUED US A CLRNC TO CROSS 20 MI N OF SAX VOR. THE FO WAS FLYING THE ACFT AND HE PROGRAMMED THE FMC TO CROSS 20 MI N OF SAX AS CLRED. THE FO CHOSE TO USE THE VNAV FEATURE TO COMPLY WITH THE CLRNC. WE LEFT 16000 FT AND THE VNAV FEATURE APPEARED TO DO WHAT IT WAS DESIGNED TO DO. DURING THE DSCNT, I NOTICED THAT THE 'MATH' DIDN'T COMPUTE TO MEET THE XING RESTR. I THEN SUGGESTED TO USE THE SPD BRAKES TO EXPEDITE THE DSCNT AND TO DECELERATE TO 250 KTS PRIOR TO PASSING 10000 FT. FO PROTESTED BY SAYING, 'THE MACHINE WILL DO IT.' WHEN IT BECAME OBVIOUS THAT THE RATE OF DSCNT WOULD NOT COMPLY WITH THE XING CLRNC, FO BECAME FIXATED AS TO WHY THE VNAV FEATURE DID NOT WORK AS PROGRAMMED. AT THIS POINT, I FULLY EXTENDED THE SPD BRAKE TO INCREASE THE RATE OF DSCNT AND DSND TO OUR ASSIGNED ALT AS RAPIDLY AS POSSIBLE. IT IS PAINFULLY OBVIOUS THAT TOO MUCH EMPHASIS IS BEING PLACED IN THE AUTOMATION AND THE BASICS OF FLYING AN ACFT ARE BEING ABANDONED. THE CONCEPT OF AUTOMATION SHOULD BE CONSIDERED AS AN AID INSTEAD OF THE PRINCIPAL MODE OF SAFELY OPERATING AN ACFT. COMMON SENSE IS RAPIDLY DWINDLING.

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.