Air carrier has stuck microphone while on approach. Diverts to problem solve as TCASII activates.

Attributes
ACN	228466
Time
Date	199212
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord tower : hpn
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 8000 flight time type : 950
ASRS Report	228466
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : overcame equipment problem flight crew : took evasive action
Consequence	Other Other
Miss Distance	horizontal : 6000
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

At approximately 14 mi southeast of ord, heading 360 degrees at 8000 ft, expecting a visual approach runway 27L, we experienced a stuck microphone. Elected to continue assigned heading and altitude while disconnecting first officer's pendant switch, head set and hand-held microphone. Squawked 7600. Had both TCASII and visual contact with other aircraft approaching ord from the north. Responded to a TCASII RA and turned northeast to heading 030 degrees where no TCASII targets were displayed. Equipment malfunction was resolved and ATC communications reestablished for a normal approach and landing. Airline maintenance in chicago replaced first officer's microphone selector panel and oxygen mask microphone panel. Aircraft returned to service. TCASII was very helpful in that it displayed a 'no target' area northeast of ord where we could go to resolve our communication problem.

Original NASA ASRS Text

Title: ACR HAS STUCK MIKE WHILE ON APCH. DIVERTS TO PROBLEM SOLVE AS TCASII ACTIVATES.

Narrative: AT APPROX 14 MI SE OF ORD, HDG 360 DEGS AT 8000 FT, EXPECTING A VISUAL APCH RWY 27L, WE EXPERIENCED A STUCK MIKE. ELECTED TO CONTINUE ASSIGNED HDG AND ALT WHILE DISCONNECTING FO'S PENDANT SWITCH, HEAD SET AND HAND-HELD MICROPHONE. SQUAWKED 7600. HAD BOTH TCASII AND VISUAL CONTACT WITH OTHER ACFT APCHING ORD FROM THE N. RESPONDED TO A TCASII RA AND TURNED NE TO HDG 030 DEGS WHERE NO TCASII TARGETS WERE DISPLAYED. EQUIP MALFUNCTION WAS RESOLVED AND ATC COMS REESTABLISHED FOR A NORMAL APCH AND LNDG. AIRLINE MAINT IN CHICAGO REPLACED FO'S MICROPHONE SELECTOR PANEL AND OXYGEN MASK MICROPHONE PANEL. ACFT RETURNED TO SVC. TCASII WAS VERY HELPFUL IN THAT IT DISPLAYED A 'NO TARGET' AREA NE OF ORD WHERE WE COULD GO TO RESOLVE OUR COM PROBLEM.

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.