A B737-300 flight crew fails to make crossing restr.

Attributes
ACN	517510
Time
Date	200107
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl bound lower : 17000 msl bound upper : 19500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Flight Phase	descent : intermediate altitude
Route In Use	arrival : profile descent
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 16500 flight time type : 13000
ASRS Report	517510
Events
Anomaly	altitude deviation : crossing restriction not met
Resolutory Action	controller : issued advisory none taken : anomaly accepted none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Chart Or Publication Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to cross konzl at 17000 ft. I started a cruise descent before the CDU programmed descent point in compliance with ATC instructions to begin our descent. I was monitoring the CDU for altitude deviation information when I realized too late that it was giving erroneous indications and that I had gotten high on the profile. At about the same time that I closed the throttles and deployed the speed brakes, ATC asked us if we were going to make the konzl restr. We replied that we'd be a little high but would do our best. We crossed konzl at FL195 instead of 17000 ft. There did not appear to be a traffic conflict with any other aircraft. We were handed off to the next controller without any complaints. My failure to more closely monitor the descent profile was the primary cause of this minor deviation. Needless to say, I'll rely on my own math from now on instead of relying on the CDU.

Original NASA ASRS Text

Title: A B737-300 FLT CREW FAILS TO MAKE XING RESTR.

Narrative: WE WERE CLRED TO CROSS KONZL AT 17000 FT. I STARTED A CRUISE DSCNT BEFORE THE CDU PROGRAMMED DSCNT POINT IN COMPLIANCE WITH ATC INSTRUCTIONS TO BEGIN OUR DSCNT. I WAS MONITORING THE CDU FOR ALTDEV INFO WHEN I REALIZED TOO LATE THAT IT WAS GIVING ERRONEOUS INDICATIONS AND THAT I HAD GOTTEN HIGH ON THE PROFILE. AT ABOUT THE SAME TIME THAT I CLOSED THE THROTTLES AND DEPLOYED THE SPD BRAKES, ATC ASKED US IF WE WERE GOING TO MAKE THE KONZL RESTR. WE REPLIED THAT WE'D BE A LITTLE HIGH BUT WOULD DO OUR BEST. WE CROSSED KONZL AT FL195 INSTEAD OF 17000 FT. THERE DID NOT APPEAR TO BE A TFC CONFLICT WITH ANY OTHER ACFT. WE WERE HANDED OFF TO THE NEXT CTLR WITHOUT ANY COMPLAINTS. MY FAILURE TO MORE CLOSELY MONITOR THE DSCNT PROFILE WAS THE PRIMARY CAUSE OF THIS MINOR DEV. NEEDLESS TO SAY, I'LL RELY ON MY OWN MATH FROM NOW ON INSTEAD OF RELYING ON THE CDU.

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.