Small aircraft on instrument practice flight has heading indicator failure and reporter points out p...

Attributes
ACN	136830
Time
Date	199002
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lex
State Reference	KY
Altitude	msl bound lower : 2000 msl bound upper : 2000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lex
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other descent : approach landing other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	other personnel other
Qualification	pilot : atp pilot : instrument pilot : commercial pilot : cfi
ASRS Report	136830
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

I was acting as a safety pilot for a local pilot who wanted to practice some apches. The ceiling was marginal and some light showers were in the area, so he filed IFR. I am an ATP and instrument instrument, qualified to act as safety pilot. The compass was checked and appeared ok during preflight. During flight, however, it gave erroneous readings and we were unable to comply with ATC instructions, flying, I estimate, 30 degree off our assigned heading. No traffic conflict resulted. When advised of our navigation problem by ATC the PIC cancelled IFR and we proceeded visually to the airport and landed west/O incident. As an instrument I see a lot of poorly maintained compasses in small private aircraft. It often causes problems for the controllers. This simple piece of equipment is very important. Perhaps an advisory circular on this subject would be helpful. I also find it is hard to verify a compass problem on the ground and even harder once airborne if the error is relatively small.

Original NASA ASRS Text

Title: SMA ON INSTRUMENT PRACTICE FLT HAS HEADING INDICATOR FAILURE AND REPORTER POINTS OUT PREVELANCE OF POORLY MAINTAINED HEADING INDICATORS ON SMA, PRIVATELY OWNED ACFT.

Narrative: I WAS ACTING AS A SAFETY PLT FOR A LCL PLT WHO WANTED TO PRACTICE SOME APCHES. THE CEILING WAS MARGINAL AND SOME LIGHT SHOWERS WERE IN THE AREA, SO HE FILED IFR. I AM AN ATP AND INSTRUMENT INSTR, QUALIFIED TO ACT AS SAFETY PLT. THE COMPASS WAS CHKED AND APPEARED OK DURING PREFLT. DURING FLT, HOWEVER, IT GAVE ERRONEOUS READINGS AND WE WERE UNABLE TO COMPLY WITH ATC INSTRUCTIONS, FLYING, I ESTIMATE, 30 DEG OFF OUR ASSIGNED HDG. NO TFC CONFLICT RESULTED. WHEN ADVISED OF OUR NAV PROB BY ATC THE PIC CANCELLED IFR AND WE PROCEEDED VISUALLY TO THE ARPT AND LANDED W/O INCIDENT. AS AN INSTR I SEE A LOT OF POORLY MAINTAINED COMPASSES IN SMALL PRIVATE ACFT. IT OFTEN CAUSES PROBS FOR THE CTLRS. THIS SIMPLE PIECE OF EQUIPMENT IS VERY IMPORTANT. PERHAPS AN ADVISORY CIRCULAR ON THIS SUBJECT WOULD BE HELPFUL. I ALSO FIND IT IS HARD TO VERIFY A COMPASS PROB ON THE GND AND EVEN HARDER ONCE AIRBORNE IF THE ERROR IS RELATIVELY SMALL.

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.

Small aircraft on instrument practice flight has heading indicator failure and reporter points out prevelance of poorly maintained heading indicators on small aircraft, privately owned aircraft.