An air carrier A300 freighter flight crew suffers a stuck microphone and loses radio contact.

Attributes
ACN	398340
Time
Date	199804
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : lax
State Reference	CA
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	A300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 15000 flight time type : 1000
ASRS Report	398340
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Flight in an A300 on apr/xa/98 operating mem/iah/lax. Radios and intercom operated normally from both seats prior to arrival in lax. After clearance received consistent with filed routing over tnp (paradise 2 arrival/pdz.PDZ2) and subsequent clearance direct civet, no further radio xmissions were received or capable of origination. Numerous attempts were made to raise ZLA from both seats, on both VHF #1 and VHF #2 on multiple frequencys, without success. The first officer yoke microphone activation switch had failed/stuck and caused a 'hot microphone' making communications impossible. When discovered, communications were re-established 20-40 NM prior to civet. ZLA issued a right 360 degree turn, descent and sequence for the arrival without incident. Aircraft maintenance log was used to detail the problem for repair upon arrival in lax.

Original NASA ASRS Text

Title: AN ACR A300 FREIGHTER FLC SUFFERS A STUCK MIKE AND LOSES RADIO CONTACT.

Narrative: FLT IN AN A300 ON APR/XA/98 OPERATING MEM/IAH/LAX. RADIOS AND INTERCOM OPERATED NORMALLY FROM BOTH SEATS PRIOR TO ARR IN LAX. AFTER CLRNC RECEIVED CONSISTENT WITH FILED ROUTING OVER TNP (PARADISE 2 ARR/PDZ.PDZ2) AND SUBSEQUENT CLRNC DIRECT CIVET, NO FURTHER RADIO XMISSIONS WERE RECEIVED OR CAPABLE OF ORIGINATION. NUMEROUS ATTEMPTS WERE MADE TO RAISE ZLA FROM BOTH SEATS, ON BOTH VHF #1 AND VHF #2 ON MULTIPLE FREQS, WITHOUT SUCCESS. THE FO YOKE MICROPHONE ACTIVATION SWITCH HAD FAILED/STUCK AND CAUSED A 'HOT MIKE' MAKING COMS IMPOSSIBLE. WHEN DISCOVERED, COMS WERE RE-ESTABLISHED 20-40 NM PRIOR TO CIVET. ZLA ISSUED A R 360 DEG TURN, DSCNT AND SEQUENCE FOR THE ARR WITHOUT INCIDENT. ACFT MAINT LOG WAS USED TO DETAIL THE PROB FOR REPAIR UPON ARR IN LAX.

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.