Air carrier large transport altitude deviation excursion from clearance altitude.

Attributes
ACN	100797
Time
Date	198812
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : fak airport : phl
State Reference	VA
Altitude	msl bound lower : 28600 msl bound upper : 29000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other descent other
Route In Use	arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : instrument pilot : flight engineer
Experience	flight time last 90 days : 250 flight time total : 5000 flight time type : 350
ASRS Report	100797
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 7000
ASRS Report	100494
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation Pilot Deviation

Narrative:

We were given a clearance to descend to FL290 and arrive there at 20 NM northeast of flat rock (dupont 2 STAR). Both the captain and myself heard center clear us to FL240. However due to the amount of talk over the radio (very busy) we wanted to verify our clearance during the descent. I 'hovered' at FL290 until confirmation by center. We told them we were descending to FL240 and received a 'roger'. I then continued my descent and at 28600' on my altimeter, center called and told us to maintain FL290. We climbed back up to FL290. To our knowledge, no incidents occurred.

Original NASA ASRS Text

Title: ACR LGT ALT DEVIATION EXCURSION FROM CLRNC ALT.

Narrative: WE WERE GIVEN A CLRNC TO DSND TO FL290 AND ARRIVE THERE AT 20 NM NE OF FLAT ROCK (DUPONT 2 STAR). BOTH THE CAPT AND MYSELF HEARD CENTER CLEAR US TO FL240. HOWEVER DUE TO THE AMOUNT OF TALK OVER THE RADIO (VERY BUSY) WE WANTED TO VERIFY OUR CLRNC DURING THE DSCNT. I 'HOVERED' AT FL290 UNTIL CONFIRMATION BY CENTER. WE TOLD THEM WE WERE DSNDING TO FL240 AND RECEIVED A 'ROGER'. I THEN CONTINUED MY DSCNT AND AT 28600' ON MY ALTIMETER, CENTER CALLED AND TOLD US TO MAINTAIN FL290. WE CLIMBED BACK UP TO FL290. TO OUR KNOWLEDGE, NO INCIDENTS OCCURRED.

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.