Altitude deviation altitude undershot. Crossing restriction not complied with.

Attributes
ACN	123705
Time
Date	198909
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : rbv
State Reference	NJ
Altitude	msl bound lower : 11000 msl bound upper : 12500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : v123
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 : 4650 flight time type : 3000
ASRS Report	123705
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : undershoot altitude deviation : crossing restriction not met non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were to identify to cross holey intersection at 1100 ft. I was flying the aircraft coupled on the autoplt. I programmed the correct data into the FMC, and selected 11000 ft on the MCP. The aircraft indicated a top of descent in 17 mi. Having confidence in the system, I switched attention to creating waypoints for approach and appropriate runway. I thought to myself, 'we should have started down by now;' we were 10 mi from the intersection and 13000 ft high. Immediately I started a rapid descent and we crossed holey at 12500 ft. My point is that I have almost 3000 hours int his airplane, and I am very knowledgeable in its operation, but pilots cannot rely on the computers to fly the aircraft.

Original NASA ASRS Text

Title: ALT DEVIATION ALT UNDERSHOT. CROSSING RESTRICTION NOT COMPLIED WITH.

Narrative: WE WERE TO IDENT TO CROSS HOLEY INTXN AT 1100 FT. I WAS FLYING THE ACFT COUPLED ON THE AUTOPLT. I PROGRAMMED THE CORRECT DATA INTO THE FMC, AND SELECTED 11000 FT ON THE MCP. THE ACFT INDICATED A TOP OF DSCNT IN 17 MI. HAVING CONFIDENCE IN THE SYS, I SWITCHED ATTN TO CREATING WAYPOINTS FOR APCH AND APPROPRIATE RWY. I THOUGHT TO MYSELF, 'WE SHOULD HAVE STARTED DOWN BY NOW;' WE WERE 10 MI FROM THE INTXN AND 13000 FT HIGH. IMMEDIATELY I STARTED A RAPID DSCNT AND WE CROSSED HOLEY AT 12500 FT. MY POINT IS THAT I HAVE ALMOST 3000 HRS INT HIS AIRPLANE, AND I AM VERY KNOWLEDGEABLE IN ITS OPERATION, BUT PLTS CANNOT RELY ON THE COMPUTERS TO FLY THE ACFT.

Data retrieved from NASA's ASRS site as of August 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.