GA small aircraft lost VOR navigation capability when in clouds. ZME gave vectors back to departure ...

Attributes
ACN	93608
Time
Date	198808
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : pgo
State Reference	OK
Altitude	msl bound lower : 3000 msl bound upper : 6000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zme
Operator	general aviation : corporate
Make Model Name	Small Aircraft, High Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 45 flight time total : 337
ASRS Report	93608
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : critical non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	aircraft : equipment problem dissipated controller : provided flight assist other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Flight in VMC prior to descending into approximately 3500' thick cloud layer. Identify confirmed on pgo on changeover from fsm. Upon entering clouds close to pgo VOR started small scallop. Believing to be in cone of ambiguity continued on heading. ZME asked if turn had been started. I replied waiting for flag to switch. ZME then said they had me 5 mi south of pgo. I then asked for vector to intercept approach course. Prior to intercept I try to find why I overflew pgo. On intercept I used both navs to track out on 105 degree right. Upon reaching approximately 3000' MSL, between layers, navs worked perfect. At end of approach back into clouds navs scalloped again. Upon executing a missed approach at 5000' MSL I asked for vectors to fsm. In clear (out of clouds) fsm in idented and seems to work perfect. No further problem to landing. Contributing factors: my complacency and indecision let things go as far as they did. Also, after talking with an avionics technician it was brought up that maybe an intermittent bad bond on a surface could cause some sort of static buildup. This happened once very shortlived over a yr ago and has not done so since until this incident.

Original NASA ASRS Text

Title: GA SMA LOST VOR NAVIGATION CAPABILITY WHEN IN CLOUDS. ZME GAVE VECTORS BACK TO DEP ARPT.

Narrative: FLT IN VMC PRIOR TO DSNDING INTO APPROX 3500' THICK CLOUD LAYER. IDENT CONFIRMED ON PGO ON CHANGEOVER FROM FSM. UPON ENTERING CLOUDS CLOSE TO PGO VOR STARTED SMALL SCALLOP. BELIEVING TO BE IN CONE OF AMBIGUITY CONTINUED ON HDG. ZME ASKED IF TURN HAD BEEN STARTED. I REPLIED WAITING FOR FLAG TO SWITCH. ZME THEN SAID THEY HAD ME 5 MI S OF PGO. I THEN ASKED FOR VECTOR TO INTERCEPT APCH COURSE. PRIOR TO INTERCEPT I TRY TO FIND WHY I OVERFLEW PGO. ON INTERCEPT I USED BOTH NAVS TO TRACK OUT ON 105 DEG R. UPON REACHING APPROX 3000' MSL, BTWN LAYERS, NAVS WORKED PERFECT. AT END OF APCH BACK INTO CLOUDS NAVS SCALLOPED AGAIN. UPON EXECUTING A MISSED APCH AT 5000' MSL I ASKED FOR VECTORS TO FSM. IN CLEAR (OUT OF CLOUDS) FSM IN IDENTED AND SEEMS TO WORK PERFECT. NO FURTHER PROB TO LNDG. CONTRIBUTING FACTORS: MY COMPLACENCY AND INDECISION LET THINGS GO AS FAR AS THEY DID. ALSO, AFTER TALKING WITH AN AVIONICS TECHNICIAN IT WAS BROUGHT UP THAT MAYBE AN INTERMITTENT BAD BOND ON A SURFACE COULD CAUSE SOME SORT OF STATIC BUILDUP. THIS HAPPENED ONCE VERY SHORTLIVED OVER A YR AGO AND HAS NOT DONE SO SINCE UNTIL THIS INCIDENT.

Data retrieved from NASA's ASRS site as of August 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.

GA small aircraft lost VOR navigation capability when in clouds. ZME gave vectors back to departure airport.