ATR72 crew had altitude excursion.

Attributes
ACN	441390
Time
Date	199906
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : cha.airport
State Reference	TN
Altitude	msl bound lower : 3300 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : cha.tracon
Operator	common carrier : air carrier
Make Model Name	ATR 72
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 300 flight time total : 10000 flight time type : 700
ASRS Report	441390
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Cleared to 4000 ft MSL, airport in sight, aircraft to follow in sight. Autoplt was disengaged, altitude alerter did not go off. First officer noticed altitude 3300 ft MSL returned to 4000 ft MSL. No conflict.

Original NASA ASRS Text

Title: ATR72 CREW HAD ALT EXCURSION.

Narrative: CLRED TO 4000 FT MSL, ARPT IN SIGHT, ACFT TO FOLLOW IN SIGHT. AUTOPLT WAS DISENGAGED, ALT ALERTER DID NOT GO OFF. FO NOTICED ALT 3300 FT MSL RETURNED TO 4000 FT MSL. NO CONFLICT.

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.