A cpr jet at FL410 loses communication with ZDC when the AWOS station at fdk, md, interferes with frequency 124.87, transmitting its information on the same frequency.

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Attributes
ACN	407543
Time
Date	199807
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mol
State Reference	VA
Altitude	msl bound lower : 41000 msl bound upper : 41000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Navigation In Use	Other
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp pilot : cfi
Experience	flight time last 90 days : 45 flight time total : 8479 flight time type : 761
ASRS Report	407543
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Navigational Facility
Air Traffic Incident	other
Situations
Navigational Aid	Unspecified

Narrative:

We were in contact with ZTL approximately 70 mi south of mol VOR when fdk, md, municipal AWOS also operating on 124.87 washed out ZTL. Unable to contact ZTL we resorted to a cpr pilot airport/FBO directory book for a center frequency. After about 3 handoffs we again established ATC communication. Total time without positive communication about 15-18 mins. Due to our altitude of 41000 ft, I felt we were dealing with big sky, little airplane and see and be seen. Had our altitude been down with the acrs I would be much more concerned. This is not the only of the AWOS's and ATIS frequencys that wash out ATC, although this is the first time we were unable to talk through and get a handoff. ATIS and AWOS frequencys should be completely separate from ATC functions frequencys. Just like ILS frequencys are separate from VOR frequencys. At least when the one controller off keyed his microphone you could still communicate to get a new frequency.

Original NASA ASRS Text

Title: A CPR JET AT FL410 LOSES COM WITH ZDC WHEN THE AWOS STATION AT FDK, MD, INTERFERES WITH FREQ 124.87, XMITTING ITS INFO ON THE SAME FREQ.

Narrative: WE WERE IN CONTACT WITH ZTL APPROX 70 MI S OF MOL VOR WHEN FDK, MD, MUNI AWOS ALSO OPERATING ON 124.87 WASHED OUT ZTL. UNABLE TO CONTACT ZTL WE RESORTED TO A CPR PLT ARPT/FBO DIRECTORY BOOK FOR A CTR FREQ. AFTER ABOUT 3 HDOFS WE AGAIN ESTABLISHED ATC COM. TOTAL TIME WITHOUT POSITIVE COM ABOUT 15-18 MINS. DUE TO OUR ALT OF 41000 FT, I FELT WE WERE DEALING WITH BIG SKY, LITTLE AIRPLANE AND SEE AND BE SEEN. HAD OUR ALT BEEN DOWN WITH THE ACRS I WOULD BE MUCH MORE CONCERNED. THIS IS NOT THE ONLY OF THE AWOS'S AND ATIS FREQS THAT WASH OUT ATC, ALTHOUGH THIS IS THE FIRST TIME WE WERE UNABLE TO TALK THROUGH AND GET A HDOF. ATIS AND AWOS FREQS SHOULD BE COMPLETELY SEPARATE FROM ATC FUNCTIONS FREQS. JUST LIKE ILS FREQS ARE SEPARATE FROM VOR FREQS. AT LEAST WHEN THE ONE CTLR OFF KEYED HIS MIKE YOU COULD STILL COMMUNICATE TO GET A NEW FREQ.

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.