MD11 crew descends below cleared altitude in mct airspace.

Attributes
ACN	413870
Time
Date	199809
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : mct
State Reference	FO
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mct
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 100 flight time total : 12000 flight time type : 150
ASRS Report	413870
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 130 flight time total : 11000 flight time type : 1300
ASRS Report	413424
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were in the descent into manchester, first officer. The first officer copied the ATIS as 29.98 and we put 29.98 into altimeter without changing to millibars. The correct altimeter was 998 millibars. As we descended through 4000 ft the controller advised us we were doing so, and asked if we had reset our altimeters correctly. We then realized our mistake and immediately changed our settings to 998 millibars and climbed to 4000 ft. There was no conflicting traffic. The remainder of the flight was normal.

Original NASA ASRS Text

Title: MD11 CREW DSNDS BELOW CLRED ALT IN MCT AIRSPACE.

Narrative: WE WERE IN THE DSCNT INTO MANCHESTER, FO. THE FO COPIED THE ATIS AS 29.98 AND WE PUT 29.98 INTO ALTIMETER WITHOUT CHANGING TO MILLIBARS. THE CORRECT ALTIMETER WAS 998 MILLIBARS. AS WE DSNDED THROUGH 4000 FT THE CTLR ADVISED US WE WERE DOING SO, AND ASKED IF WE HAD RESET OUR ALTIMETERS CORRECTLY. WE THEN REALIZED OUR MISTAKE AND IMMEDIATELY CHANGED OUR SETTINGS TO 998 MILLIBARS AND CLBED TO 4000 FT. THERE WAS NO CONFLICTING TFC. THE REMAINDER OF THE FLT WAS NORMAL.

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.