Cpr PIC names a myriad of reasons for an altitude deviation altitude overshot in descent.

Attributes
ACN	170552
Time
Date	199102
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : oak
State Reference	CA
Altitude	msl bound lower : 2500 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak tower : sfo
Operator	general aviation : corporate
Make Model Name	Light Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 100 flight time total : 8000 flight time type : 2000
ASRS Report	170552
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While making rapid descent, approximately 3000 FPM at 250 KTS, at the request of approach control I descended below my assigned altitude of 3000' to approximately 2500'. I was flying on the autoplt. Both the copilot's and my attention was focused outside looking for the airport and numerous other aircraft that were close by. The autoplt failed to capture the altitude, 3000', that was selected. Also, the altitude alerter failed to go off until I was 300' below my altitude, 2700'. I recognized my problem and disengaged the autoplt and climbed back to 3000'. Contributing factors and human considerations: approaching an unfamiliar airport at high speed and high sink rate, with many potential traffic conflicts, with reduced visibility. Overdependence on autoplt and altitude alerter. Pilot fatigue--both got in the night before at about xx pm from a 4 day trip, arose early am for this trip, which was delayed until near midday. Plus, both pilots have the flu.

Original NASA ASRS Text

Title: CPR PIC NAMES A MYRIAD OF REASONS FOR AN ALT DEVIATION ALT OVERSHOT IN DESCENT.

Narrative: WHILE MAKING RAPID DSNT, APPROX 3000 FPM AT 250 KTS, AT THE REQUEST OF APCH CTL I DSNDED BELOW MY ASSIGNED ALT OF 3000' TO APPROX 2500'. I WAS FLYING ON THE AUTOPLT. BOTH THE COPLT'S AND MY ATTN WAS FOCUSED OUTSIDE LOOKING FOR THE ARPT AND NUMEROUS OTHER ACFT THAT WERE CLOSE BY. THE AUTOPLT FAILED TO CAPTURE THE ALT, 3000', THAT WAS SELECTED. ALSO, THE ALT ALERTER FAILED TO GO OFF UNTIL I WAS 300' BELOW MY ALT, 2700'. I RECOGNIZED MY PROB AND DISENGAGED THE AUTOPLT AND CLBED BACK TO 3000'. CONTRIBUTING FACTORS AND HUMAN CONSIDERATIONS: APCHING AN UNFAMILIAR ARPT AT HIGH SPD AND HIGH SINK RATE, WITH MANY POTENTIAL TFC CONFLICTS, WITH REDUCED VISIBILITY. OVERDEPENDENCE ON AUTOPLT AND ALT ALERTER. PLT FATIGUE--BOTH GOT IN THE NIGHT BEFORE AT ABOUT XX PM FROM A 4 DAY TRIP, AROSE EARLY AM FOR THIS TRIP, WHICH WAS DELAYED UNTIL NEAR MIDDAY. PLUS, BOTH PLTS HAVE THE FLU.

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.