B737 receives urgent immediate change to altitude clearance from departure in new york area.

Attributes
ACN	456170
Time
Date	199911
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : n90.tracon
State Reference	NY
Altitude	msl bound lower : 12000 msl bound upper : 12500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90.tracon
Operator	common carrier : air carrier
Make Model Name	B737-400
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : commercial pilot : atp
Experience	flight time last 90 days : 135 flight time total : 13500 flight time type : 135
ASRS Report	456170
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
Events
Anomaly	conflict : airborne less severe other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : separated traffic none taken : anomaly accepted
Supplementary
Problem Areas	ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

Flight was cleared to 15000 ft. Passing 12500 ft, departure control called for an immediate descent to 12000 ft (reason unknown).

Original NASA ASRS Text

Title: B737 RECEIVES URGENT IMMEDIATE CHANGE TO ALT CLRNC FROM DEP IN NEW YORK AREA.

Narrative: FLT WAS CLRED TO 15000 FT. PASSING 12500 FT, DEP CTL CALLED FOR AN IMMEDIATE DSCNT TO 12000 FT (REASON UNKNOWN).

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.