ACR PENETRATED ATA AT CHO WITHOUT ESTABLISHING RADIO CONTACT WITH TWR. POSSIBLE CLOSE PROX WITH SMALL ACFT IN TRAFFIC PATTERN.

Narrative

DURING THE DSCNT INTO CHARLOTTESVILLE ARPT; WE RECEIVED CLRNC TO 6000'; FOLLOWED CLOSELY BY FURTHER CLRNC TO 4000'. AFTER RPTING THE ARPT IN SIGHT; WE WERE CLRED FOR THE VISUAL APCH TO RWY 03; AND ADVISED TO CONTACT TWR. WE WERE ENCOUNTERING A LOUD SIDE TONE BLEED THROUGH FROM AN UNKNOWN SOURCE WHICH WAS CAUSING RECEPTION DIFFICULTY; AND DELAYED OUR CONTACT WITH THE TWR WHILE WE ATTEMPTED TO REMEDY THE PROB. AFTER LNDG; THE TWR REQUESTED THAT WE CONTACT THEM FURTHER OUT IN THE FUTURE. WE LATER RECEIVED A PHONE CALL FROM SMA ACFT Y PLT WHO WAS TURNING BASE LEG AS WE RPTED IN ON FINAL APCH. A FOLLOW UP PHONE CALL WITH THE TWR REVEALED THAT WE HAD NOT FLOWN CLOSER THAN 'ABOUT 2 MI' FROM THAT ACFT. NEITHER CREW MEMBER COULD RECALL RECEIVING AN ALTITUDE RESTRICTION AT 4000'; WHICH MY PHONE CONVERSATION WITH WASHINGTON CENTER INDICATED THAT WE SHOULD HAVE RECEIVED. UPON MY PHONE REQUEST; WASHINGTON CENTER LISTENED TO OUR TAPE AND LATER ADVISED ME THAT THEIR LAST XMISSION TO US HAD BEEN: '(FLT CALL SIGN); CLRED FOR THE VISUAL APCH; RWY 3; RADAR SVC TERMINATED; CONTACT THE TWR ON 124.5 BEFORE LEAVING FOUR.' IT APPEARS THAT A COMBINATION OF RADIO INTERFERENCE; CLOSE PROX TO THE ARPT; AND THE 3 BRIEF WORDS; 'BEFORE LEAVING FOUR;' TRAILING AT THE END OF THE LONG XMISSION MAY HAVE COMBINED TO CAUSE THE CREW TO MISS THIS RESTRICTION. FOR LOCAL PLTS AND CTLRS WHO ARE VERY FAMILIAR WITH THESE LOCAL PROCS; TACKING THE BRIEF 'BEFORE LEAVING FOUR' AT THE END IS PROBABLY ADEQUATE AND ANTICIPATED. SINCE THIS PROC IS NOT WRITTEN ON ANY OF THE ARPT PROCS; AND IS NOT ANTICIPATED BY THE FLT CREWS WHO ARE UNFAMILIAR WITH THIS AGREEMENT; IT WOULD PROBABLY BE BETTER; AND MORE THOROUGH TO EMPHASIZE THIS RESTRICTION WITH THE MORE SPECIFIC PHRASEOLOGY; 'MAINTAIN 4000' UNTIL CONTACTING THE TWR ON 124.5.' MOST FREQUENTLY; THE TERM 'CLRED FOR THE VISUAL APCH;' IS ACCEPTED AS A RELEASE FROM ANY PREVIOUS ALT RESTRICTIONS; AND MOST ALT RESTRICTIONS ARE GIVEN IN A MANNER THAT REQUIRES AND ANTICIPATES A READBACK. THE STANDARD TERM 'CLRED FOR THE VISUAL APCH;' FOLLOWED AT THE VERY END BY THE LESS OBVIOUS; 'BEFORE LEAVING FOUR;' TENDS TO OBSCURE THE LATTER AND IS COMPARABLE TO A TFC COP WAVING YOU THROUGH A RED LIGHT.