An MU300 diamond jet loses communication with ZLA while IMC on a departure from las. The faulty rado...

Attributes
ACN	426414
Time
Date	199901
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : las
State Reference	NV
Altitude	msl bound lower : 15000 msl bound upper : 23000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : corporate
Make Model Name	MU-300 Diamond 1/1A
Route In Use	departure other departure sid : sid
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 100 flight time total : 6600 flight time type : 380
ASRS Report	426414
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	aircraft : equipment problem dissipated
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

After departure from las, we were climbing to FL230 on the SID. Immediately upon entering the overcast at approximately 15000 ft, both communications receivers emitted a loud static sound and we could no longer hear ATC. We had experienced this problem to a lesser degree several weeks prior. In that instance, we were still able to hear ATC with some difficulty and found that the problem disappeared when reaching clear skies above the clouds. The aircraft at that time was inspected and the radome grounding was determined to be the problem. The radome was sent in for repairs and a 'loaner' unit was installed for our use. When we reached our cleared altitude of FL230 we were still IMC and could not receive. Our original clearance had been to expect FL330 2 mins after departure so we set code 7600 in our transponder and announced 'in the blind' that we were starting a climb to FL330. At that point, reception had improved and we could hear ATC with some difficulty. After several mins, ATC cleared us to FL330 and we began our climb. As before once on top, our reception was fine. Apparently the 'loaner' radome we received was worse than the original. A lack of IMC prevented a proper check at installation.

Original NASA ASRS Text

Title: AN MU300 DIAMOND JET LOSES COM WITH ZLA WHILE IMC ON A DEP FROM LAS. THE FAULTY RADOME GROUNDING WAS CREATING STATIC THAT PREVENTED 2-WAY COM.

Narrative: AFTER DEP FROM LAS, WE WERE CLBING TO FL230 ON THE SID. IMMEDIATELY UPON ENTERING THE OVCST AT APPROX 15000 FT, BOTH COMS RECEIVERS EMITTED A LOUD STATIC SOUND AND WE COULD NO LONGER HEAR ATC. WE HAD EXPERIENCED THIS PROB TO A LESSER DEG SEVERAL WKS PRIOR. IN THAT INSTANCE, WE WERE STILL ABLE TO HEAR ATC WITH SOME DIFFICULTY AND FOUND THAT THE PROB DISAPPEARED WHEN REACHING CLR SKIES ABOVE THE CLOUDS. THE ACFT AT THAT TIME WAS INSPECTED AND THE RADOME GROUNDING WAS DETERMINED TO BE THE PROB. THE RADOME WAS SENT IN FOR REPAIRS AND A 'LOANER' UNIT WAS INSTALLED FOR OUR USE. WHEN WE REACHED OUR CLRED ALT OF FL230 WE WERE STILL IMC AND COULD NOT RECEIVE. OUR ORIGINAL CLRNC HAD BEEN TO EXPECT FL330 2 MINS AFTER DEP SO WE SET CODE 7600 IN OUR XPONDER AND ANNOUNCED 'IN THE BLIND' THAT WE WERE STARTING A CLB TO FL330. AT THAT POINT, RECEPTION HAD IMPROVED AND WE COULD HEAR ATC WITH SOME DIFFICULTY. AFTER SEVERAL MINS, ATC CLRED US TO FL330 AND WE BEGAN OUR CLB. AS BEFORE ONCE ON TOP, OUR RECEPTION WAS FINE. APPARENTLY THE 'LOANER' RADOME WE RECEIVED WAS WORSE THAN THE ORIGINAL. A LACK OF IMC PREVENTED A PROPER CHK AT INSTALLATION.

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.

An MU300 diamond jet loses communication with ZLA while IMC on a departure from las. The faulty radome grounding was creating static that prevented 2-WAY communication.