E145 crew did not start descent when cleared by ATC.

Attributes
ACN	491570
Time
Date	200011
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : clt.airport
State Reference	NC
Altitude	msl bound lower : 24000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : multi engine
Experience	flight time last 90 days : 250 flight time total : 2100 flight time type : 700
ASRS Report	491570
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot altitude deviation : excursion from assigned altitude non adherence : company policies non adherence : clearance non adherence : published procedure
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to original clearance flight crew : returned to assigned altitude none taken : detected after the fact
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While at cruise at FL270, ATC advised to descend to FL240. I acknowledged the clearance by readback. The captain was flying, I was working the radios. At this time I advised the captain that I was going to be on the other radio in order to obtain ATIS and call company operations. The apt dialed FL240 into the autoplt. I accomplished this task and about 4 mins passed. I started monitoring communication #1 again. At this time, ATC asked if we had been cleared to FL240. I advised we did. At this time, I saw that we were still at FL270. The captain saw this also and we descended to FL240 at once. As far as I know there was no traffic conflict. There was nothing on TCASII. After dialing FL240 into the autoplt, the captain and myself failed to confirm the aircraft started a descent, thus causing the problem.

Original NASA ASRS Text

Title: E145 CREW DID NOT START DSCNT WHEN CLRED BY ATC.

Narrative: WHILE AT CRUISE AT FL270, ATC ADVISED TO DSND TO FL240. I ACKNOWLEDGED THE CLRNC BY READBACK. THE CAPT WAS FLYING, I WAS WORKING THE RADIOS. AT THIS TIME I ADVISED THE CAPT THAT I WAS GOING TO BE ON THE OTHER RADIO IN ORDER TO OBTAIN ATIS AND CALL COMPANY OPS. THE APT DIALED FL240 INTO THE AUTOPLT. I ACCOMPLISHED THIS TASK AND ABOUT 4 MINS PASSED. I STARTED MONITORING COM #1 AGAIN. AT THIS TIME, ATC ASKED IF WE HAD BEEN CLRED TO FL240. I ADVISED WE DID. AT THIS TIME, I SAW THAT WE WERE STILL AT FL270. THE CAPT SAW THIS ALSO AND WE DSNDED TO FL240 AT ONCE. AS FAR AS I KNOW THERE WAS NO TFC CONFLICT. THERE WAS NOTHING ON TCASII. AFTER DIALING FL240 INTO THE AUTOPLT, THE CAPT AND MYSELF FAILED TO CONFIRM THE ACFT STARTED A DSCNT, THUS CAUSING THE PROB.

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.