Date: 201703
Local time of day: 0601-1200
Location: ZFW.ARTCC, TX
Flight conditions: IMC
Weather elements / visibility: Cloudy; Rain; 5
Light: Daylight
Aircraft: Skylane 182/RG Turbo Skylane/RG
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Descent
Airspace: Class E ZFW
ATC / advisory: Center ZFW
Aircraft component: Compass (HSI/ETC)
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Instrument
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Landed As Precaution; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: After IFR release I lined up on the runway and checked the vertical card compass and Directional Gyro (DG) to verify they were lined up on runway heading of 140 degrees. On climb out on an initial course of 130 I encountered clouds at 1;600 feet. After climbing to assigned altitude of 3;000 feet and course 110 I rechecked the DG against the compass and noticed that the DG was reading 110; but the compass was reading between 100 and 105. I reset the DG and mentioned to my passenger that it looked like the DG was precessing a little and I would have to watch it. We continued for about 15 minutes while I checked the DG and compass about every 5 minutes; never needing to adjust more than a few degrees. Fort Worth Center advised me I was 15 degrees off course and correct to the right. I had set the DG previously; moving the card less than 5 degrees from the previous setting. I reset the DG and advised center that my DG was becoming unreliable. As I approached my destination; I was directed to descend to 2;100 and course 040.I turned to 040 using the compass and center advised me that I was far off course and to correct. The compass showed me at 040. I advised center that both my DG and compass were unreliable and I was switching to GPS track. While I was trying to sort out the compass and track situation my attention was diverted from controlling the airplane resulting in deviations in attitude and altitude. After several minutes of trying to sort out the problem I requested that Center allow me to climb above the clouds so I could sort out what was working and what was not. I climbed to 4;500 feet and determined that the compass had errors of between 20-60 degrees depending upon heading and the DG was slowly rotating. The vacuum indicator was showing in the green range and the attitude indicator was functioning correctly. I determined that the airplane was not suitable or safe for IFR and Center asked if I wanted vectors to the nearest VFR airport. I accepted and continued VFR above the clouds eventually climbing to 5;500 to remain clear of the clouds until I was near [the airport] and the clouds broke up. I landed; parked the airplane and rented a car to complete my trip.I had flown the airplane a week earlier and did not notice any compass or DG problems; however it was a daytime VFR flight in the local area and I cannot say with absolute certainty that I checked the compass and DG any time after I set them prior to departure.During the flight my attention was distracted by the compounding DG and compass errors and that distraction caused several deviations from level flight. When I finally decided to quit trying to figure out the problem I was able to climb through the clouds where there was less concentration needed to maintain level flight.The Controllers did a very good job of keeping me clear of other aircraft and provided all assistance they could.The initial problem of the precessing DG did not appear severe enough to warrant the termination of the flight; however the DG continued to deteriorate and when I discovered that the compass was also unreliable; the combination of losing navigation sources and the fact that those problems were causing me to lose situational awareness; I decided that the only solution was to terminate IFR and get back on the ground safely.




Synopsis: C182R pilot reported terminating an IFR flight after experiencing compass and directional gyro issues.