Light transport descends below assigned altitude on approach.

Attributes
ACN	274215
Time
Date	199406
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : tup
State Reference	MS
Altitude	msl bound lower : 2400 msl bound upper : 2700
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	descent : approach
Route In Use	approach : straight in
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 3210 flight time type : 40
ASRS Report	274215
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

ATC cleared us to maintain 2700 ft MSL and call tup in sight for the visual. At 2700 ft we were in and out of the clouds. I was PNF and looking for the field. The first officer was also looking for the field and was descending. When I glanced inside I noticed we were 300 ft low (2400 ft) and descending. I ordered the first officer to climb back to 2700 ft and he did. Total deviation 300 ft. Flight continued without event. PF on visual approachs should always fly on instruments until the PNF sees airport.

Original NASA ASRS Text

Title: LTT DSNDS BELOW ASSIGNED ALT ON APCH.

Narrative: ATC CLRED US TO MAINTAIN 2700 FT MSL AND CALL TUP IN SIGHT FOR THE VISUAL. AT 2700 FT WE WERE IN AND OUT OF THE CLOUDS. I WAS PNF AND LOOKING FOR THE FIELD. THE FO WAS ALSO LOOKING FOR THE FIELD AND WAS DSNDING. WHEN I GLANCED INSIDE I NOTICED WE WERE 300 FT LOW (2400 FT) AND DSNDING. I ORDERED THE FO TO CLB BACK TO 2700 FT AND HE DID. TOTAL DEV 300 FT. FLT CONTINUED WITHOUT EVENT. PF ON VISUAL APCHS SHOULD ALWAYS FLY ON INSTS UNTIL THE PNF SEES ARPT.

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.