HELI PLT ENTERED CLASS C AT BHM WITHOUT ATC CLRNC DUE TO COM PROBS.

Narrative

WE DEPARTED; AS USUAL; ALONG THE S SIDE OF THE RIDGELINE. THIS WAS OUR SECOND DEP FROM THIS LOCATION THIS MORNING. AS DEPS AT BHM WERE USING RWY 24; WE HEADED E ALONG THE RIDGELINE. THIS IS IN ACCORDANCE WITH AN (PERHAPS UNOFFICIAL?) LOA FROM ABOUT 4.5 YRS AGO; WITH BIRMINGHAM TWR. IMMEDIATELY UPON LIFTING FROM THE PAD; AND ESTABLISHING SAFE FLT; I CALLED BIRMINGHAM TWR FOR VFR CLRNC TO THE N. THERE WAS NO RESPONSE; SO I WAITED A FEW MORE SECONDS; THINKING MAYBE I WAS NOT YET HIGH ENOUGH ABOVE THE RIDGELINE FOR THEM TO HEAR ME. I TRIED THE SAME CALL AGAIN. IT SOUNDED LIKE I WAS STEPPED ON BY TWR; OR ANOTHER DEPARTING ACFT. THERE WAS CONVERSATION GOING ON ABOUT TAXI-CLRNC FOR ONE OF THE COMMERCIAL JETS PREPARING TO DEPART RWY 6. I WASN'T SURE IF TWR HAD HEARD ME THAT TIME AGAIN OR NOT. TWR SAID SOMETHING TO THE EFFECT OF 2 ACFT READING BACK THAT CLRNC AT ONCE; AND I WAS EXPECTING TO HEAR ONE OR MORE OF THE AIRLINE PLTS TO RE-ACKNOWLEDGE CLRNC; SO I HESITATED TO ENSURE NOT 'WALKING ON THEM' YET AGAIN. AT THIS TIME; THE TWR ANNOUNCED FOR THE ACFT 2 MI S AT 1500 FT TO DECLARE. I WAS JUST ABOUT TO REPEAT AGAIN MY CALL ANYWAY; WHEN THIS HAPPENED. I GAVE THE CALL SIGN; AND REQUESTED VFR CLRNC TO THE N; ETC; AS USUAL. THE TWR CTLR WAS OBVIOUSLY MAD AT THIS TIME ALREADY; AND IT SHOWED. HE STARTED GRIPING ABOUT ME NOT CALLING SOONER. I TRIED TO EXPLAIN TO HIM THAT I HAD ALREADY CALLED LIKE 3 TIMES; WITHOUT SUCCESS. (IT MIGHT HAVE BEEN THRICE; BUT MAYBE ONLY TWICE; I CANNOT RECALL.) HE SAID SOMETHING LIKE THAT WASN'T GOOD ENOUGH; THAT IT WAS 'A LITTLE LATE NOW;' AND THAT I WAS WELL WITHIN CLASS C AIRSPACE (AS IF I DIDN'T KNOW THAT). I THEN TRIED TO TELL HIM THAT I HAD JUST LIFTED (THINKING HE MIGHT HAVE THOUGHT I HAD JUST FLOWN IN FROM THE S WITHOUT MAKING ANY CALLS) AND THAT HE WOULD REALIZE THAT I WASN'T ABLE TO ESTABLISH COMS ANY SOONER; AND THAT IS WHY I WAS SUDDENLY THERE ON HIS RADAR; CLOSE BY IN HIS AIRSPACE. I DO NOT BELIEVE I DID ANYTHING WRONG/ILLEGAL/OR STUPID. YES; IN RETROSPECT; I MIGHT HAVE BEEN MORE 'AGGRESSIVE' GETTING MY CALL THROUGH; BUT AT THAT TIME; I WAS UNSURE IF I COULD DO THAT; SINCE I HAD ALREADY TRIED AT LEAST TWICE; OR MORE; WITHOUT SUCCESS. FURTHERMORE; I WAS ON THE S SIDE OF THE RIDGELINE THAT ENTIRE TIME; AS PER OUR EARLIER AGREEMENT; AND DO NOT KNOW OF ANY OTHER AIR TFC THAT WAS ANYWHERE IN MY VICINITY. I HAVE BEEN DOING THIS MISSION SUCCESSFULLY HERE FOR THE LAST 5 YRS; WITHOUT A PROB; SINCE THAT ONE INITIAL INCIDENT; WHICH LED TO OUR LOA. I WAS IN ACCORDANCE WITH THAT THE WHOLE TIME. I DO NOT KNOW WHAT ELSE I COULD HAVE DONE TO MAKE THIS A BETTER; OR SAFER TRANSITION.