B727 cargo crew had altitude excursion on descent.

Attributes
ACN	417854
Time
Date	199810
Day	Sat
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : mem
State Reference	TN
Altitude	msl bound lower : 4700 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : mem tracon : atl
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 5000
ASRS Report	417854
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 90 flight time total : 3300 flight time type : 800
ASRS Report	418142
Events
Anomaly	altitude deviation : overshoot non adherence : far non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified 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:

Assigned descent to 5000 ft MSL, aircraft descended through 5000 ft to 4700 ft, corrective action taken immediately. Time below 5000 ft MSL approximately 10 seconds maximum. Crew diverted by concern for TCA (class B) altitude assignments and associated airspeed restrs (200 KIAS). Supplemental information from acn 418142: my attention (PNF) was diverted by concern for TCA (class B) floor, and descending below it. I saw on the chart that the floor was 5000 ft and thought -- no problem to worry about until they descend us lower. I looked up and saw us passing 4900 ft, and warned the captain.

Original NASA ASRS Text

Title: B727 CARGO CREW HAD ALT EXCURSION ON DSCNT.

Narrative: ASSIGNED DSCNT TO 5000 FT MSL, ACFT DSNDED THROUGH 5000 FT TO 4700 FT, CORRECTIVE ACTION TAKEN IMMEDIATELY. TIME BELOW 5000 FT MSL APPROX 10 SECONDS MAX. CREW DIVERTED BY CONCERN FOR TCA (CLASS B) ALT ASSIGNMENTS AND ASSOCIATED AIRSPD RESTRS (200 KIAS). SUPPLEMENTAL INFO FROM ACN 418142: MY ATTN (PNF) WAS DIVERTED BY CONCERN FOR TCA (CLASS B) FLOOR, AND DSNDING BELOW IT. I SAW ON THE CHART THAT THE FLOOR WAS 5000 FT AND THOUGHT -- NO PROB TO WORRY ABOUT UNTIL THEY DSND US LOWER. I LOOKED UP AND SAW US PASSING 4900 FT, AND WARNED THE CAPT.

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.