Narrative:

During taxi noticed slaved dg fluctuating back and forth trying to lock on to signal. Simply thought it was cold soaked, that explained its long time to finally lock on. After run up prior to taxi dg finally indicated lock on and warning flag dropped. Normal takeoff except for high winds and turbulence. Tower final clearance turn to a heading of 270 degrees after lift off. Started turn and noticed dg not rolling at appropriate rate. Stopped turn. Tower called and told me to contact departure. Complied. Tried to check heading with compass but turbulence made that difficult. However, recognized heading 40-50 degrees off. Departure called and said to continue turn. Told departure had dg problem and needed to return to airport. Departure issued a vector heading. I pushed fast slaving button to bring dg back in line with compass. Started vector turn. Dg failed to turn at appropriate rate. Dialed in company frequency to contact home base to inform them of problem. Encountered strong drafts. Altitude varied 100-200'. Departure requested flying conditions. Informed them and requested block altitude at same time. Granted block altitude. Then requested approximately heading as ground saw it. No response. Unbeknownst to me, had accidentally knocked off departure frequency. Called home base and informed them of problem. Called departure again with no response. Switched back to tower and called them. They said I was not given permission to leave departure frequency. Told them could not raise departure. Meanwhile aircraft was just about to pass over airport when tower asked if I saw airport. Answered in the affirmative. Altitude was 2000' above airport elevation as I passed over the first quarter of runway. Tower cleared me for visibility to the airport. Rolled left to enter approximately downwind and started a slow descent so as not to hurt passenger ears. Tower called and asked me to confirm I saw the airport. I said yes, and that I was simply using this heading to lose altitude. They then cleared me to land, reversed course and landed. Problems encountered were that I became preoccupied with the failing piece of equipment, should have visualized on taxi what I would do in the event of dg failing in air and how I was going to handle it. To simplify my workload in the future, if the compass becomes as jostled by turbulence as it was this time, when I inform ATC of dg problems I will ask for no gyro vectors instead of trying to fight out the problem in my head. Also, home base can wait to be communicated with until I get on the ground. I will practice a little more fervently compass turns during practice sessions.

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Original NASA ASRS Text

Title: AN ERRATIC DIRECTIONAL GYRO CAUSED GRIEF FOR REPORTER.

Narrative: DURING TAXI NOTICED SLAVED DG FLUCTUATING BACK AND FORTH TRYING TO LOCK ON TO SIGNAL. SIMPLY THOUGHT IT WAS COLD SOAKED, THAT EXPLAINED ITS LONG TIME TO FINALLY LOCK ON. AFTER RUN UP PRIOR TO TAXI DG FINALLY INDICATED LOCK ON AND WARNING FLAG DROPPED. NORMAL TKOF EXCEPT FOR HIGH WINDS AND TURB. TWR FINAL CLRNC TURN TO A HDG OF 270 DEGS AFTER LIFT OFF. STARTED TURN AND NOTICED DG NOT ROLLING AT APPROPRIATE RATE. STOPPED TURN. TWR CALLED AND TOLD ME TO CONTACT DEP. COMPLIED. TRIED TO CHK HDG WITH COMPASS BUT TURB MADE THAT DIFFICULT. HOWEVER, RECOGNIZED HDG 40-50 DEGS OFF. DEP CALLED AND SAID TO CONTINUE TURN. TOLD DEP HAD DG PROB AND NEEDED TO RETURN TO ARPT. DEP ISSUED A VECTOR HDG. I PUSHED FAST SLAVING BUTTON TO BRING DG BACK IN LINE WITH COMPASS. STARTED VECTOR TURN. DG FAILED TO TURN AT APPROPRIATE RATE. DIALED IN COMPANY FREQ TO CONTACT HOME BASE TO INFORM THEM OF PROB. ENCOUNTERED STRONG DRAFTS. ALT VARIED 100-200'. DEP REQUESTED FLYING CONDITIONS. INFORMED THEM AND REQUESTED BLOCK ALT AT SAME TIME. GRANTED BLOCK ALT. THEN REQUESTED APPROX HDG AS GND SAW IT. NO RESPONSE. UNBEKNOWNST TO ME, HAD ACCIDENTALLY KNOCKED OFF DEP FREQ. CALLED HOME BASE AND INFORMED THEM OF PROB. CALLED DEP AGAIN WITH NO RESPONSE. SWITCHED BACK TO TWR AND CALLED THEM. THEY SAID I WAS NOT GIVEN PERMISSION TO LEAVE DEP FREQ. TOLD THEM COULD NOT RAISE DEP. MEANWHILE ACFT WAS JUST ABOUT TO PASS OVER ARPT WHEN TWR ASKED IF I SAW ARPT. ANSWERED IN THE AFFIRMATIVE. ALT WAS 2000' ABOVE ARPT ELEVATION AS I PASSED OVER THE FIRST QUARTER OF RWY. TWR CLRED ME FOR VIS TO THE ARPT. ROLLED LEFT TO ENTER APPROX DOWNWIND AND STARTED A SLOW DSCNT SO AS NOT TO HURT PAX EARS. TWR CALLED AND ASKED ME TO CONFIRM I SAW THE ARPT. I SAID YES, AND THAT I WAS SIMPLY USING THIS HDG TO LOSE ALT. THEY THEN CLRED ME TO LAND, REVERSED COURSE AND LANDED. PROBS ENCOUNTERED WERE THAT I BECAME PREOCCUPIED WITH THE FAILING PIECE OF EQUIP, SHOULD HAVE VISUALIZED ON TAXI WHAT I WOULD DO IN THE EVENT OF DG FAILING IN AIR AND HOW I WAS GOING TO HANDLE IT. TO SIMPLIFY MY WORKLOAD IN THE FUTURE, IF THE COMPASS BECOMES AS JOSTLED BY TURB AS IT WAS THIS TIME, WHEN I INFORM ATC OF DG PROBS I WILL ASK FOR NO GYRO VECTORS INSTEAD OF TRYING TO FIGHT OUT THE PROB IN MY HEAD. ALSO, HOME BASE CAN WAIT TO BE COMMUNICATED WITH UNTIL I GET ON THE GND. I WILL PRACTICE A LITTLE MORE FERVENTLY COMPASS TURNS DURING PRACTICE SESSIONS.

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.