Air carrier flight experiences an altitude excursion following the routing of the mitts 1 STAR into ...

Attributes
ACN	463584
Time
Date	200002
Day	Thu
Local Time Of Day	0001 To 0600
Place
Locale Reference	intersection : civet
State Reference	CA
Altitude	msl bound lower : 13500 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sct.tracon
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : mitts one
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 156 flight time total : 13700 flight time type : 500
ASRS Report	463584
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued alert flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to civet intersection for the mitts 1 arrival. We descended to 14000 ft as instructed. En route to civet, we were told that we could expect runway 25. Upon arrival at civet, we joined the arrival radial and advised ATC that we were departing 14000 ft for 12000 ft. ATC responded 'negative, maintain 14000 ft and contact approach control.' we had already descended about 500 ft and immediately climbed back to 14000 ft and followed normal vectors for the ILS to runway 25R. No traffic conflict was involved. However, I just wanted to be sure this was not considered an altitude deviation since we were following our ATC arrival clearance.

Original NASA ASRS Text

Title: ACR FLT EXPERIENCES AN ALT EXCURSION FOLLOWING THE ROUTING OF THE MITTS 1 STAR INTO LAX.

Narrative: WE WERE CLRED TO CIVET INTXN FOR THE MITTS 1 ARR. WE DSNDED TO 14000 FT AS INSTRUCTED. ENRTE TO CIVET, WE WERE TOLD THAT WE COULD EXPECT RWY 25. UPON ARR AT CIVET, WE JOINED THE ARR RADIAL AND ADVISED ATC THAT WE WERE DEPARTING 14000 FT FOR 12000 FT. ATC RESPONDED 'NEGATIVE, MAINTAIN 14000 FT AND CONTACT APCH CTL.' WE HAD ALREADY DSNDED ABOUT 500 FT AND IMMEDIATELY CLBED BACK TO 14000 FT AND FOLLOWED NORMAL VECTORS FOR THE ILS TO RWY 25R. NO TFC CONFLICT WAS INVOLVED. HOWEVER, I JUST WANTED TO BE SURE THIS WAS NOT CONSIDERED AN ALTDEV SINCE WE WERE FOLLOWING OUR ATC ARR CLRNC.

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.

Air carrier flight experiences an altitude excursion following the routing of the mitts 1 STAR into lax.