An L1011 first officer reported that his captain misunderstood and descended 300 ft too low near phl...

Attributes
ACN	479520
Time
Date	200007
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : phl.airport
State Reference	PA
Altitude	msl single value : 6000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : phl.tracon
Operator	common carrier : air carrier
Make Model Name	L-1011 Tri-Star All Series
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors arrival star : n/s
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : instrument pilot : multi engine pilot : commercial
Experience	flight time last 90 days : 120 flight time total : 4932 flight time type : 274
ASRS Report	479520
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	controller : issued advisory flight crew : became reoriented
Consequence	other
Supplementary
Problem Areas	FAA Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

The captain misunderstood ATC instructions and descended 300 ft below assigned altitude before deviation was noted. No loss of separation occurred. The approach controller was giving too many instructions too fast -- airspeed change, heading change, and a perceived altitude change.

Original NASA ASRS Text

Title: AN L1011 FO RPTED THAT HIS CAPT MISUNDERSTOOD AND DSNDED 300 FT TOO LOW NEAR PHL.

Narrative: THE CAPT MISUNDERSTOOD ATC INSTRUCTIONS AND DSNDED 300 FT BELOW ASSIGNED ALT BEFORE DEV WAS NOTED. NO LOSS OF SEPARATION OCCURRED. THE APCH CTLR WAS GIVING TOO MANY INSTRUCTIONS TOO FAST -- AIRSPD CHANGE, HDG CHANGE, AND A PERCEIVED ALT CHANGE.

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.