Setting a desired rate of descent; 1;600 FPM; into the altitude alert window vice the vertical speed...

Attributes
ACN	979041
Time
Date	201111
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZZ.Airport
State Reference	FO
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Component
Aircraft Component	Altitude Alert
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Altitude Overshoot Deviation - Procedural Clearance Inflight Event / Encounter CFTT / CFIT

Narrative:

We were cleared by approach direct to the FAF and to descend to 3;000 ft. I went heads down to copy down the current ATIS and the captain reached up to change our open descent to 3;000 to a V/south of 1;600 ft down to slow our rate of descent. I finished copying the ATIS and came heads up. Approach then called asking our altitude which was 2;300 ft. The captain has inadvertently put 1;600 in the altitude select window (staying in open descent) rather than putting in a V/south 1;600 rate of descent. We immediately climbed back to 3;000 ft. Had we been IMC and the controller not noted our mistake we could have ended in a mountain. In retrospect; I should have gotten the ATIS sooner but it was just changing.

Original NASA ASRS Text

Title: Setting a desired rate of descent; 1;600 FPM; into the Altitude Alert window vice the Vertical Speed window proved only embarrassing to the flight crew of an A320. Had ATC not alerted them to their descent below their cleared altitude of 3;000 MSL the outcome could have been more alarming.

Narrative: We were cleared by Approach direct to the FAF and to descend to 3;000 FT. I went heads down to copy down the current ATIS and the Captain reached up to change our Open Descent to 3;000 to a V/S of 1;600 FT down to slow our rate of descent. I finished copying the ATIS and came heads up. Approach then called asking our altitude which was 2;300 FT. The Captain has inadvertently put 1;600 in the altitude select window (staying in open descent) rather than putting in a V/S 1;600 rate of descent. We immediately climbed back to 3;000 FT. Had we been IMC and the Controller not noted our mistake we could have ended in a mountain. In retrospect; I should have gotten the ATIS sooner but it was just changing.

Data retrieved from NASA's ASRS site as of April 2012 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.

Setting a desired rate of descent; 1;600 FPM; into the altitude alert window vice the vertical speed window proved only embarrassing to the flight crew of an A320. Had ATC not alerted them to their descent below their cleared altitude of 3;000 MSL the outcome could have been more alarming.