B737 crew descended below their cleared altitude.

Attributes
ACN	414880
Time
Date	199809
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : fak
State Reference	VA
Altitude	msl bound lower : 4000 msl bound upper : 10000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	other other : other pilot : cfi pilot : flight engineer pilot : atp
Experience	controller non radar : 2 controller radar : 2 flight time last 90 days : 250 flight time total : 11000 flight time type : 3500
ASRS Report	414880
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 other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation Operational Deviation

Narrative:

PNF acknowledged descent from 10000 ft descending to 4000 ft, with best rate through 8000 ft for traffic. Leaving 4700 ft for 4000 ft, the controller questioned altitude leaving, then said that descent was for another aircraft. ATC left our flight at 4000 ft level until time for further descent for landing.

Original NASA ASRS Text

Title: B737 CREW DSNDED BELOW THEIR CLRED ALT.

Narrative: PNF ACKNOWLEDGED DSCNT FROM 10000 FT DSNDING TO 4000 FT, WITH BEST RATE THROUGH 8000 FT FOR TFC. LEAVING 4700 FT FOR 4000 FT, THE CTLR QUESTIONED ALT LEAVING, THEN SAID THAT DSCNT WAS FOR ANOTHER ACFT. ATC LEFT OUR FLT AT 4000 FT LEVEL UNTIL TIME FOR FURTHER DSCNT FOR LNDG.

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.