Widebody transport fails to make crossing restr.

Attributes
ACN	316691
Time
Date	199509
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : rbv
State Reference	NJ
Altitude	msl bound lower : 20000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zbw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 16000 flight time type : 2100
ASRS Report	316691
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

This flight was in the final 1/2 hour of an 8:30 hour flight. The trip had been routine, seasoned crew. This pilot with almost 4 yrs on the aircraft, all on the north atlantic. We had begun the descent early to find a better ride and were now at FL280. When ATC cleared us 'direct manta' I knew the next clearance would likely be to cross 35 NM north of manta at FL200. When we got this clearance shortly thereafter I loaded the computer and told the captain it's in the box with a 10 NM buffer. (So now we have told the aircraft to cross this new fix at 45 NM north of manta.) I figured everything was correctly set. A short while later as I was getting out of my seat to use the lavatory I heard ATC ask if we were going to start down soon. The captain looked at his 'progress page' and said 'yes,' in 10 NM. The controller said we were only 8 NM from our restr. We descended quickly and smoothly but I estimate we crossed 10-15 hundred ft high. The controller said 'no problem.' after landing this 3 pilot crew discussed our experience at length. I don't think any of us will ever know whether this was an FMC glitch, or an incorrect entry on my part into the FMC. Complacency? Only 1 pilot watching the store? Lesson learned!

Original NASA ASRS Text

Title: WDB FAILS TO MAKE XING RESTR.

Narrative: THIS FLT WAS IN THE FINAL 1/2 HR OF AN 8:30 HR FLT. THE TRIP HAD BEEN ROUTINE, SEASONED CREW. THIS PLT WITH ALMOST 4 YRS ON THE ACFT, ALL ON THE N ATLANTIC. WE HAD BEGUN THE DSCNT EARLY TO FIND A BETTER RIDE AND WERE NOW AT FL280. WHEN ATC CLRED US 'DIRECT MANTA' I KNEW THE NEXT CLRNC WOULD LIKELY BE TO CROSS 35 NM N OF MANTA AT FL200. WHEN WE GOT THIS CLRNC SHORTLY THEREAFTER I LOADED THE COMPUTER AND TOLD THE CAPT IT'S IN THE BOX WITH A 10 NM BUFFER. (SO NOW WE HAVE TOLD THE ACFT TO CROSS THIS NEW FIX AT 45 NM N OF MANTA.) I FIGURED EVERYTHING WAS CORRECTLY SET. A SHORT WHILE LATER AS I WAS GETTING OUT OF MY SEAT TO USE THE LAVATORY I HEARD ATC ASK IF WE WERE GOING TO START DOWN SOON. THE CAPT LOOKED AT HIS 'PROGRESS PAGE' AND SAID 'YES,' IN 10 NM. THE CTLR SAID WE WERE ONLY 8 NM FROM OUR RESTR. WE DSNDED QUICKLY AND SMOOTHLY BUT I ESTIMATE WE CROSSED 10-15 HUNDRED FT HIGH. THE CTLR SAID 'NO PROB.' AFTER LNDG THIS 3 PLT CREW DISCUSSED OUR EXPERIENCE AT LENGTH. I DON'T THINK ANY OF US WILL EVER KNOW WHETHER THIS WAS AN FMC GLITCH, OR AN INCORRECT ENTRY ON MY PART INTO THE FMC. COMPLACENCY? ONLY 1 PLT WATCHING THE STORE? LESSON LEARNED!

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.