B727 crew thought they descended below controller's altitude restr.

Attributes
ACN	420840
Time
Date	199811
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : orl airport : mco
State Reference	FL
Altitude	msl bound lower : 2300 msl bound upper : 2500
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mco
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	420840
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
ASRS Report	420839
Events
Anomaly	other anomaly other
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	other

Narrative:

Aircraft was issued a clearance to maintain 2500 ft until south of the orl VOR. We were level at 2500 ft when we were cleared a visual approach. First officer was flying and thought this cleared him to start descent. We were at 2300 ft before I realized we had started down. We returned to 2500 ft. No traffic conflict occurred. I discussed this with the first officer after we landed.

Original NASA ASRS Text

Title: B727 CREW THOUGHT THEY DSNDED BELOW CTLR'S ALT RESTR.

Narrative: ACFT WAS ISSUED A CLRNC TO MAINTAIN 2500 FT UNTIL S OF THE ORL VOR. WE WERE LEVEL AT 2500 FT WHEN WE WERE CLRED A VISUAL APCH. FO WAS FLYING AND THOUGHT THIS CLRED HIM TO START DSCNT. WE WERE AT 2300 FT BEFORE I REALIZED WE HAD STARTED DOWN. WE RETURNED TO 2500 FT. NO TFC CONFLICT OCCURRED. I DISCUSSED THIS WITH THE FO AFTER WE LANDED.

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.