Commuter flight crew descends below assigned altitude.

Attributes
ACN	319830
Time
Date	199510
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gcc
State Reference	WY
Altitude	msl bound lower : 8800 msl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 140 flight time total : 8500 flight time type : 380
ASRS Report	319830
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : became reoriented other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The flight a scheduled commuter far 121 regional was on descent for ILS/runway 34 at gillette, wy (gcc), on the gcc 160 degree right at 27 DME. The aircraft altitude alerter and autoplt was set to 7000 ft, as part of the approach briefing and set up. Aircraft was descending at 800 FPM and cleared for the approach. Descent (below) through the 10000 ft MEA commenced 5 NM prior to the 6400 ft approach transition at tooke intersection. ATC alerted us of our altitude deviation and we immediately established a climb back to the 10000 ft MEA. Altitude deviation resulted from crew inattention and improper autoplt altitude alerter usage.

Original NASA ASRS Text

Title: COMMUTER FLC DSNDS BELOW ASSIGNED ALT.

Narrative: THE FLT A SCHEDULED COMMUTER FAR 121 REGIONAL WAS ON DSCNT FOR ILS/RWY 34 AT GILLETTE, WY (GCC), ON THE GCC 160 DEG R AT 27 DME. THE ACFT ALT ALERTER AND AUTOPLT WAS SET TO 7000 FT, AS PART OF THE APCH BRIEFING AND SET UP. ACFT WAS DSNDING AT 800 FPM AND CLRED FOR THE APCH. DSCNT (BELOW) THROUGH THE 10000 FT MEA COMMENCED 5 NM PRIOR TO THE 6400 FT APCH TRANSITION AT TOOKE INTXN. ATC ALERTED US OF OUR ALT DEV AND WE IMMEDIATELY ESTABLISHED A CLB BACK TO THE 10000 FT MEA. ALT DEV RESULTED FROM CREW INATTENTION AND IMPROPER AUTOPLT ALT ALERTER USAGE.

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.