Missed unacknowledged clearance results in flight crew of mdt altitude deviation near dca.

Attributes
ACN	427250
Time
Date	199901
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : adw
State Reference	MD
Altitude	msl bound lower : 4000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 270 flight time total : 23000 flight time type : 1500
ASRS Report	427250
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 150 flight time total : 5000 flight time type : 1500
ASRS Report	427441
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Air Traffic Incident	Pilot Deviation

Narrative:

First officer was off calling company and ATC called traffic at 5000 ft and 1 O'clock position. We were cleared to 5000 ft and ATC asked us to level at 4000 ft, which we did not hear or acknowledge. Going through 4600 ft, ATC said we were cleared only to 4000 ft and turned us to 030 degrees. I responded that we did not hear or acknowledge the 4000 ft call. The controller's voice was difficult to understand and was using too many words to relay messages. This seems to be a common problem. Air carrier XXX maintain 4000 ft, traffic 1 O'clock 5000 ft would have been enough. The conflicting traffic had us visually and separation was maintained.

Original NASA ASRS Text

Title: MISSED UNACKNOWLEDGED CLRNC RESULTS IN FLC OF MDT ALTDEV NEAR DCA.

Narrative: FO WAS OFF CALLING COMPANY AND ATC CALLED TFC AT 5000 FT AND 1 O'CLOCK POS. WE WERE CLRED TO 5000 FT AND ATC ASKED US TO LEVEL AT 4000 FT, WHICH WE DID NOT HEAR OR ACKNOWLEDGE. GOING THROUGH 4600 FT, ATC SAID WE WERE CLRED ONLY TO 4000 FT AND TURNED US TO 030 DEGS. I RESPONDED THAT WE DID NOT HEAR OR ACKNOWLEDGE THE 4000 FT CALL. THE CTLR'S VOICE WAS DIFFICULT TO UNDERSTAND AND WAS USING TOO MANY WORDS TO RELAY MESSAGES. THIS SEEMS TO BE A COMMON PROB. ACR XXX MAINTAIN 4000 FT, TFC 1 O'CLOCK 5000 FT WOULD HAVE BEEN ENOUGH. THE CONFLICTING TFC HAD US VISUALLY AND SEPARATION WAS MAINTAINED.

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.