Altitude deviation overshoot on descent. Possible call sign problem.

Attributes
ACN	119834
Time
Date	198908
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : clt
State Reference	NC
Altitude	msl bound lower : 20000 msl bound upper : 22000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl artcc : zdv
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : ztl
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 5000 flight time type : 1000
ASRS Report	119834
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance none taken : detected after the fact other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While descending into charlotte, nc, ZTL called and cleared us to descend to FL220. I was the PNF, and I read back the clearance and set FL220 in the altitude controller, I immediately told the captain I was going off frequency to get a gate assignment and called our operations. After getting the gate and relaying some maintenance needs, I looked up and saw FL200 set in the altitude controller. I assumed the captain had been told to continue his descent to FL200. About the same time, center called and asked our altitude. I said we were passing FL210 for FL200. The controller then said we had been assigned FL220 and to level off at FL210. We complied, and after several seconds, we were told to continue our descent to cross majic intersection at 12,000' and 250 KTS. Apparently the captain heard a clearance to FL200 while I was on another radio. Since I was not talking or monitoring ATC at the time, I don't know if the clearance to FL200 was for us or some other aircraft.

Original NASA ASRS Text

Title: ALT DEVIATION OVERSHOOT ON DESCENT. POSSIBLE CALL SIGN PROBLEM.

Narrative: WHILE DESCENDING INTO CHARLOTTE, NC, ZTL CALLED AND CLRED US TO DSND TO FL220. I WAS THE PNF, AND I READ BACK THE CLRNC AND SET FL220 IN THE ALT CTLR, I IMMEDIATELY TOLD THE CAPT I WAS GOING OFF FREQ TO GET A GATE ASSIGNMENT AND CALLED OUR OPERATIONS. AFTER GETTING THE GATE AND RELAYING SOME MAINT NEEDS, I LOOKED UP AND SAW FL200 SET IN THE ALT CTLR. I ASSUMED THE CAPT HAD BEEN TOLD TO CONTINUE HIS DSCNT TO FL200. ABOUT THE SAME TIME, CENTER CALLED AND ASKED OUR ALT. I SAID WE WERE PASSING FL210 FOR FL200. THE CTLR THEN SAID WE HAD BEEN ASSIGNED FL220 AND TO LEVEL OFF AT FL210. WE COMPLIED, AND AFTER SEVERAL SECONDS, WE WERE TOLD TO CONTINUE OUR DSCNT TO CROSS MAJIC INTXN AT 12,000' AND 250 KTS. APPARENTLY THE CAPT HEARD A CLRNC TO FL200 WHILE I WAS ON ANOTHER RADIO. SINCE I WAS NOT TALKING OR MONITORING ATC AT THE TIME, I DON'T KNOW IF THE CLRNC TO FL200 WAS FOR US OR SOME OTHER ACFT.

Data retrieved from NASA's ASRS site as of August 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.