Reporter stated that flight descended below the published crossing altitude.

Attributes
ACN	432075
Time
Date	199903
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : lax.airport
State Reference	CA
Altitude	msl bound lower : 11600 msl bound upper : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival star : ns
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : private pilot : multi engine pilot : instrument pilot : atp pilot : cfi pilot : commercial
Experience	flight time last 90 days : 100 flight time total : 4600 flight time type : 125
ASRS Report	432075
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Chart Or Publication Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Descended to 11600 ft when arrival stated 12000 ft. At the last min we were assigned a new arrival and new runway. The PIC was PF. The previous arrival and fix was a clearance to cross at or below 12000 ft. The new fix was a clearance to cross at or above 12000 ft. With relatively little time to reprogram the FMS with the new arrival, get out the new approach plates, and set up for the ILS, I did not notice the PIC descending below 12000 ft. A quick check of the arrival showed him below crossing restrs by almost 500 ft about 1 1/2 - 2 mi prior to the point he was supposed to be there. I believe we were leading the pack into lax. The south runways (where we expected to land) were 'full' according to ATC -- thus the change. A little more time and notice from ZLA or socal approach would have left us more time to program the arrival into the uns-1, set up for and brief the approach to runway 24R. ATIS stated to expect another fix and approach, but when it 'filled up,' we were switched at the last min. A hurried atmosphere in the cockpit led to this error.

Original NASA ASRS Text

Title: RPTR STATED THAT FLT DSNDED BELOW THE PUBLISHED XING ALT.

Narrative: DSNDED TO 11600 FT WHEN ARR STATED 12000 FT. AT THE LAST MIN WE WERE ASSIGNED A NEW ARR AND NEW RWY. THE PIC WAS PF. THE PREVIOUS ARR AND FIX WAS A CLRNC TO CROSS AT OR BELOW 12000 FT. THE NEW FIX WAS A CLRNC TO CROSS AT OR ABOVE 12000 FT. WITH RELATIVELY LITTLE TIME TO REPROGRAM THE FMS WITH THE NEW ARR, GET OUT THE NEW APCH PLATES, AND SET UP FOR THE ILS, I DID NOT NOTICE THE PIC DSNDING BELOW 12000 FT. A QUICK CHK OF THE ARR SHOWED HIM BELOW XING RESTRS BY ALMOST 500 FT ABOUT 1 1/2 - 2 MI PRIOR TO THE POINT HE WAS SUPPOSED TO BE THERE. I BELIEVE WE WERE LEADING THE PACK INTO LAX. THE S RWYS (WHERE WE EXPECTED TO LAND) WERE 'FULL' ACCORDING TO ATC -- THUS THE CHANGE. A LITTLE MORE TIME AND NOTICE FROM ZLA OR SOCAL APCH WOULD HAVE LEFT US MORE TIME TO PROGRAM THE ARR INTO THE UNS-1, SET UP FOR AND BRIEF THE APCH TO RWY 24R. ATIS STATED TO EXPECT ANOTHER FIX AND APCH, BUT WHEN IT 'FILLED UP,' WE WERE SWITCHED AT THE LAST MIN. A HURRIED ATMOSPHERE IN THE COCKPIT LED TO THIS ERROR.

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.