C525 pilot and the captain had an altitude deviation in phx class B.

Attributes
ACN	603831
Time
Date	200312
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : phx.airport
State Reference	AZ
Altitude	msl bound lower : 8000 msl bound upper : 10600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : p50.tracon
Operator	general aviation : corporate
Make Model Name	Citationjet, C525/C526
Operating Under FAR Part	Part 91
Navigation In Use	other
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : corporate
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 31 flight time total : 5000 flight time type : 78
ASRS Report	603831
Person 2
Affiliation	company : corporate
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approaching phx for arrival, we were on vectors towards the airport from the northeast. We were expecting a visual approach to runway 8L. While level at 10000 ft we were given a change in heading and an altitude assignment of 8000 ft. I acknowledged the change in heading and altitude on the radio to ATC. The PIC selected the new heading and new altitude in the flight director. I verified the selections. The autoplt, which was engaged, turned to the new heading but was not commanded to begin the descent by the PIC. Vertical speed was selected by the PIC but was not commanded to descend. Instead, when vertical speed was selected the aircraft must have been in a slight climb of 100-200 FPM. The autoplt then climbed the aircraft until we noticed several mins later we were not at our assigned altitude. The reason this situation arose is that both pilots on board were focused on programming the FMS for the approach we were to expect. I believe the reason this became a problem is that current procedure is to have the PF not only fly the airplane but also select altitudes and headings for the flight director and also program the FMS. The PNF is left only to talk on the radios. I believe the situation could have been avoided by a better division of duties. The PF should fly the airplane. The PNF should program the FMS with a verification of the programming done by the PF.

Original NASA ASRS Text

Title: C525 PLT AND THE CAPT HAD AN ALTDEV IN PHX CLASS B.

Narrative: APCHING PHX FOR ARR, WE WERE ON VECTORS TOWARDS THE ARPT FROM THE NE. WE WERE EXPECTING A VISUAL APCH TO RWY 8L. WHILE LEVEL AT 10000 FT WE WERE GIVEN A CHANGE IN HDG AND AN ALT ASSIGNMENT OF 8000 FT. I ACKNOWLEDGED THE CHANGE IN HDG AND ALT ON THE RADIO TO ATC. THE PIC SELECTED THE NEW HDG AND NEW ALT IN THE FLT DIRECTOR. I VERIFIED THE SELECTIONS. THE AUTOPLT, WHICH WAS ENGAGED, TURNED TO THE NEW HDG BUT WAS NOT COMMANDED TO BEGIN THE DSCNT BY THE PIC. VERT SPD WAS SELECTED BY THE PIC BUT WAS NOT COMMANDED TO DSND. INSTEAD, WHEN VERT SPD WAS SELECTED THE ACFT MUST HAVE BEEN IN A SLIGHT CLB OF 100-200 FPM. THE AUTOPLT THEN CLBED THE ACFT UNTIL WE NOTICED SEVERAL MINS LATER WE WERE NOT AT OUR ASSIGNED ALT. THE REASON THIS SIT AROSE IS THAT BOTH PLTS ON BOARD WERE FOCUSED ON PROGRAMMING THE FMS FOR THE APCH WE WERE TO EXPECT. I BELIEVE THE REASON THIS BECAME A PROB IS THAT CURRENT PROC IS TO HAVE THE PF NOT ONLY FLY THE AIRPLANE BUT ALSO SELECT ALTS AND HDGS FOR THE FLT DIRECTOR AND ALSO PROGRAM THE FMS. THE PNF IS LEFT ONLY TO TALK ON THE RADIOS. I BELIEVE THE SIT COULD HAVE BEEN AVOIDED BY A BETTER DIVISION OF DUTIES. THE PF SHOULD FLY THE AIRPLANE. THE PNF SHOULD PROGRAM THE FMS WITH A VERIFICATION OF THE PROGRAMMING DONE BY THE PF.

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.