SMT HAS GYROSCOPE FAILURE ON IFR FLT PLAN IN MIXED CONDITIONS. RETURN LAND.

Narrative

SMT WAS CLRED FOR AN IFR DEP; RWY HDG 19L AT IAD ON FILE TO ILG. THE TWR HANDED US OVER TO DEP. DEP TOLD ME TO TURN R TO A SPECIFIC HDG. I DID; AND AFTER ABOUT 15 SECONDS ON THAT HDG; DEP CAME ON AND SAID 'SMT I TOLD YOU TO BE ON A HDG OF XXX.' I THEN REALIZED THAT THE DIRECTIONAL GYROSCOPE WAS ON THE FRITZ (IT APPEARED AS IF THE MAGNETIC SLAVING UNIT WAS NOT DONG ITS JOB). I TOLD DEP OF MY SIT AND HE GAVE ME ANOTHER HDG. TIMING THE TURN (OR TRYING TO; IT WAS CONTINUOUS CHOP AND I WAS STILL CLBING); I TURNED TO THIS NEW HDG. AGAIN; THE CTLR CAME ON AND SAID 'SMT I WANT YOU ON THIS HDG.' I TOLD HIM AGAIN THAT I WAS HAVING PROBS AND BY THIS TIME MY ALT WAS NOW 500 FT ABOUT WHAT I WAS ASSIGNED. I WAS CORRECTING THE ALT PROB AS THE CTLR CAME BACK ON AND ADVISED ME OF MY ALT VARIATION. AGAIN; HE GAVE ME A NEW HDG. THEN HE ASKED IF I WAS HAVING GYROSCOPE PROBS. AT THIS MOMENT I SNAPPED BACK AND SAID 'YES; FOR THE 3RD TIME; YES; I AM HAVING A PROB WITH MY GYROSCOPE.' (I AM NOW AT 7000 FT AND IN AND OUT OF IMC BUILDING CUMULU NIMBUS.) AFTER THIS; THINGS STARTED TO SLOW DOWN AS HE GAVE ME 'NO GYROSCOPE TURNS' THEN I TRIED TO RESOLVE THE SIT IN STRAIGHT AND LEVEL FLT; BUT I WAS UNABLE TO DO SO. I RETURNED BACK TO IAD BECAUSE APCH CTL WOULD NOT ALLOW NO GYROSCOPES TO ILG. I LANDED IAD AND LOOKED FOR AN AVIONICS TECHNICIAN (WITH NO LUCK). BECAUSE THE WX WAS DEFINITELY IMPROVING; I DECIDED TO GO VFR TO ILG WHERE REPAIRS WOULD BE ATTEMPTED. MY FINAL DEST WAS 3B2. I DEPARTED IAD VFR. CLRNC WAS ADVISED OF THE SIT AND TOLD ME HE WOULD WORK OUT HDOFS FOR THIS FLT ('THE WHOLE WAY'). WELL; THEIR INTENTIONS WERE GOOD; BUT MY MISTAKE WAS TO RELY ON THIS. DEP CTL'S WORKLOAD GOT TOO HVY AND THEY WERE UNABLE TO WORK OUT A HDOF. SO; THEY TOLD ME TO REMAIN CLR OF THE TCA; RADAR SVC TERMINATED; AND RESUMED OWN NAV. (HOWEVER; JUST BEFORE HE WAS ABOUT TO TERMINATE RADAR SVC; I NOTICED THAT THE NOSE GEAR WAS STILL DOWN BUT THE MAINS WERE UP -- WHAT A DAY!) I PAUSED AND REPEATED WHAT HE SAID; BUT HE THEN (30 SECONDS) CAME BACK ON AND TOLD ME I WAS IN THE TCA AND APCH WANTED TO TALK TO ME. I CONTACTED APCH; TOLD THEM OF MY INTENTIONS; DEST AND REQUESTED 9500 FT. WITHOUT HESITATION THEY CLRED ME TO 9500 FT. AFTER I LEVELED OFF THE CTLR ASKED ME TO COPY A PHONE NUMBER AND HIS NAME AND TO CONTACT HIM WHEN I LANDED. AT XA30Z I PHONED HIM AND WE WORKED THINGS OUT OVER THE PHONE. WHEN HE REALIZED THAT I ACTUALLY KNEW WHAT I WAS DOING HE TOLD ME THAT EVERYTHING IS OK AND NOT TO WORRY ABOUT A VIOLATION. IN SUMMARY: I FEEL THAT I COULD HAVE AVOIDED THE SIT HAD I MADE IT CLR TO THE CTLR THAT I WAS IN NEED OF CONTINUED FLT FOLLOWING DUE TO AN UNRELIABLE DIRECTIONAL GYROSCOPE AND NOT TO ALLOW HIM TO TERMINATE RADAR SVC; WHICH WAS REQUESTED TO IAD CLRNC DELIVERY.