Aircraft equipment problem. Rmp (radio management panel) frequency changes without pilot input.

Attributes
ACN	320406
Time
Date	199511
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : rdu
State Reference	NC
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 190 flight time total : 8500 flight time type : 430
ASRS Report	320406
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During vectors for the ILS runway 23R approach at rdu in A320 airbus the #1 radio (communication) switched frequencys on its own, without pilot input. This initial uncommanded switch caused us to miss an approach controller instruction to intercept the localizer inbound. Upon discovering the radio malfunction, we contacted rdu approach and received vectors for the runway 23L approach. The malfunction occurred 2 more times during the approach and landing. No TA's or RA's were encountered during this equipment malfunction.

Original NASA ASRS Text

Title: ACFT EQUIP PROB. RMP (RADIO MGMNT PANEL) FREQ CHANGES WITHOUT PLT INPUT.

Narrative: DURING VECTORS FOR THE ILS RWY 23R APCH AT RDU IN A320 AIRBUS THE #1 RADIO (COM) SWITCHED FREQS ON ITS OWN, WITHOUT PLT INPUT. THIS INITIAL UNCOMMANDED SWITCH CAUSED US TO MISS AN APCH CTLR INSTRUCTION TO INTERCEPT THE LOC INBOUND. UPON DISCOVERING THE RADIO MALFUNCTION, WE CONTACTED RDU APCH AND RECEIVED VECTORS FOR THE RWY 23L APCH. THE MALFUNCTION OCCURRED 2 MORE TIMES DURING THE APCH AND LNDG. NO TA'S OR RA'S WERE ENCOUNTERED DURING THIS EQUIP MALFUNCTION.

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.