Widebody transport aircraft on descent misses crossing restriction.

Attributes
ACN	223044
Time
Date	199209
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ard
State Reference	NJ
Altitude	msl bound lower : 11000 msl bound upper : 21000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : on vectors enroute airway : zdc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 175 flight time total : 7000 flight time type : 600
ASRS Report	223044
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

At FL260 center gave us a restriction to cross somto intersection at 11000 ft. The first officer was flying (myself) and the captain read back the restriction. I programmed the FMS to cross somto at 11000. At the time the clearance was received, we were approximately 40 mi south of somto. The FMS captured VNAV path and began to descend. The captain excused himself to use the lavatory descending. While he was away, I began to program the approach into lga. When I was finished, I went to the descent page on the FMC in order to check the progress of our descent. I noticed that the FMC was predicating the descent on dials at 2500 ft, an altitude which I had programmed in for the approach. At that moment, I turned to the direct intercept to see distance from somto. I observed that we were 13 mi south of somto at FL210. I immediately called center to confirm somto at 11000 ft. The controller issued an immediate turn to heading 180 degrees. During this clearance the captain returned to the cockpit. I immediately made a right and increased the rate of descent to over 6000 FPM. After about 30 degrees of turn, center turned us back to the north to intercept the nanci arrival north of somto. One of the mistakes I made was assuming that after the aircraft captured VNAV path in the descent that it would make the crossing restriction and require no supervision. When I put the 2500 ft altitude at dials in, somehow the FMC accepted that as its crossing restriction. It is possible that I may have erred with my input, but I don't know how. Another mistake was changing from the map display to the plan display in programming the approach. With 1 pilot out of the seat and the other in the plan mode, there is certainly diminished position awareness. No amount of technology relieves the pilots of their duties of basic airmanship. Technological advancements have in my opinion greatly enhanced and improved virtually all facets of aviation, however, errors will still be made by both the machinery and the pilots who control the machinery and in this particular incident, complacency was certainly a factor.

Original NASA ASRS Text

Title: WDB ACFT ON DSCNT MISSES XING RESTRICTION.

Narrative: AT FL260 CTR GAVE US A RESTRICTION TO CROSS SOMTO INTXN AT 11000 FT. THE FO WAS FLYING (MYSELF) AND THE CAPT READ BACK THE RESTRICTION. I PROGRAMMED THE FMS TO CROSS SOMTO AT 11000. AT THE TIME THE CLRNC WAS RECEIVED, WE WERE APPROX 40 MI S OF SOMTO. THE FMS CAPTURED VNAV PATH AND BEGAN TO DSND. THE CAPT EXCUSED HIMSELF TO USE THE LAVATORY DSNDING. WHILE HE WAS AWAY, I BEGAN TO PROGRAM THE APCH INTO LGA. WHEN I WAS FINISHED, I WENT TO THE DSCNT PAGE ON THE FMC IN ORDER TO CHK THE PROGRESS OF OUR DSCNT. I NOTICED THAT THE FMC WAS PREDICATING THE DSCNT ON DIALS AT 2500 FT, AN ALT WHICH I HAD PROGRAMMED IN FOR THE APCH. AT THAT MOMENT, I TURNED TO THE DIRECT INTERCEPT TO SEE DISTANCE FROM SOMTO. I OBSERVED THAT WE WERE 13 MI S OF SOMTO AT FL210. I IMMEDIATELY CALLED CTR TO CONFIRM SOMTO AT 11000 FT. THE CTLR ISSUED AN IMMEDIATE TURN TO HDG 180 DEGS. DURING THIS CLRNC THE CAPT RETURNED TO THE COCKPIT. I IMMEDIATELY MADE A R AND INCREASED THE RATE OF DSCNT TO OVER 6000 FPM. AFTER ABOUT 30 DEGS OF TURN, CTR TURNED US BACK TO THE N TO INTERCEPT THE NANCI ARR N OF SOMTO. ONE OF THE MISTAKES I MADE WAS ASSUMING THAT AFTER THE ACFT CAPTURED VNAV PATH IN THE DSCNT THAT IT WOULD MAKE THE XING RESTRICTION AND REQUIRE NO SUPERVISION. WHEN I PUT THE 2500 FT ALT AT DIALS IN, SOMEHOW THE FMC ACCEPTED THAT AS ITS XING RESTRICTION. IT IS POSSIBLE THAT I MAY HAVE ERRED WITH MY INPUT, BUT I DON'T KNOW HOW. ANOTHER MISTAKE WAS CHANGING FROM THE MAP DISPLAY TO THE PLAN DISPLAY IN PROGRAMMING THE APCH. WITH 1 PLT OUT OF THE SEAT AND THE OTHER IN THE PLAN MODE, THERE IS CERTAINLY DIMINISHED POS AWARENESS. NO AMOUNT OF TECHNOLOGY RELIEVES THE PLTS OF THEIR DUTIES OF BASIC AIRMANSHIP. TECHNOLOGICAL ADVANCEMENTS HAVE IN MY OPINION GREATLY ENHANCED AND IMPROVED VIRTUALLY ALL FACETS OF AVIATION, HOWEVER, ERRORS WILL STILL BE MADE BY BOTH THE MACHINERY AND THE PLTS WHO CTL THE MACHINERY AND IN THIS PARTICULAR INCIDENT, COMPLACENCY WAS CERTAINLY A FACTOR.

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.