Medium large transport overshot assigned altitude during descent.

Attributes
ACN	142806
Time
Date	199004
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lax
State Reference	CA
Altitude	msl bound lower : 9500 msl bound upper : 10000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lax
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 3000 flight time type : 90
ASRS Report	142806
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 5000 flight time type : 325
ASRS Report	143754
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : overshoot
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were approaching lax runway 25L on the published ILS. ARTCC cleared us to descend to be at 10000' at 30 DME and 8000' at 25 DME. We were watching radar, trying to avoid buildups and thought we were cleared at or below 10000' at 30 DME. At 33 DME and 9500' approach control told us to maintain 10000'. We complied. Contributing factors: new first officer (1 yr in commercial aviation and 6 months as first officer with domineering captain). We were busy with the WX and misunderstood the clearance. The captain asked me as we approached 10000' if we were cleared 'at or below' or just 'at'. I said I didn't know. He didn't ask/tell me to clarify it, so I didn't. He had been interfering/intervening with everything I had done the entire 3 day trip. By the end, I was fully 'subjugated' to the 'command' of the left seater. Another victim of the copilot syndrome. Supplemental information from acn 143754. Copilot put in 8000' in altitude alerter. At 9500' at 35 DME I asked copilot to verify instructions with controller. But before he could do so we were handed off to next controller. Next controller said to maintain 10000'. He did not say that we deviated, but in retrospect I think we may have.

Original NASA ASRS Text

Title: MLG OVERSHOT ASSIGNED ALT DURING DESCENT.

Narrative: WE WERE APCHING LAX RWY 25L ON THE PUBLISHED ILS. ARTCC CLRED US TO DSND TO BE AT 10000' AT 30 DME AND 8000' AT 25 DME. WE WERE WATCHING RADAR, TRYING TO AVOID BUILDUPS AND THOUGHT WE WERE CLRED AT OR BELOW 10000' AT 30 DME. AT 33 DME AND 9500' APCH CTL TOLD US TO MAINTAIN 10000'. WE COMPLIED. CONTRIBUTING FACTORS: NEW F/O (1 YR IN COMMERCIAL AVIATION AND 6 MONTHS AS F/O WITH DOMINEERING CAPT). WE WERE BUSY WITH THE WX AND MISUNDERSTOOD THE CLRNC. THE CAPT ASKED ME AS WE APCHED 10000' IF WE WERE CLRED 'AT OR BELOW' OR JUST 'AT'. I SAID I DIDN'T KNOW. HE DIDN'T ASK/TELL ME TO CLARIFY IT, SO I DIDN'T. HE HAD BEEN INTERFERING/INTERVENING WITH EVERYTHING I HAD DONE THE ENTIRE 3 DAY TRIP. BY THE END, I WAS FULLY 'SUBJUGATED' TO THE 'COMMAND' OF THE L SEATER. ANOTHER VICTIM OF THE COPLT SYNDROME. SUPPLEMENTAL INFO FROM ACN 143754. COPLT PUT IN 8000' IN ALT ALERTER. AT 9500' AT 35 DME I ASKED COPLT TO VERIFY INSTRUCTIONS WITH CTLR. BUT BEFORE HE COULD DO SO WE WERE HANDED OFF TO NEXT CTLR. NEXT CTLR SAID TO MAINTAIN 10000'. HE DID NOT SAY THAT WE DEVIATED, BUT IN RETROSPECT I THINK WE MAY HAVE.

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.