PWR LINE PATROL UNABLE TO COMMUNICATE WITH MIL AUX TRAINING FIELD.

Narrative

I WAS FLYING LOW LEVEL ALONG A PWR LINE. AN OBSERVER FROM THE ELECTRIC PWR COMPANY WITH WHOM WE (FBO) HAD A CONTRACT; WAS ALSO ON BOARD; CHKING THE PWR LINES FOR THE CAUSE OF A PWR OUTAGE. PRIOR TO THE FLT; I ATTEMPTED TO DETERMINE THE FREQ OF TAC 1 AHP (ARMY HELIPORT) SINCE I KNEW I WOULD BE OPERATING IN THAT VICINITY. SINCE DOD PUBS LISTING MIL FREQS ARE NOT GENERALLY AVAILABLE TO THE PUBLIC; THIS SEARCH WAS UNSUCCESSFUL. I ELECTED TO BROADCAST MY INTENTIONS ON THE MULTICOM FREQ OF THE NEARBY UNCTLED ARPT. AS I APCHED TAC 1 AHP (ON 2 OCCASIONS); I ANNOUNCED MY POS AND INTENTIONS MULTIPLE TIMES WITHOUT A RESPONSE FROM ANYONE; ALTHOUGH I COULD SEE MIL HELIS OPERATING AT THE AHP. I ORBITED SEVERAL TIMES TO AVOID CONFLICTING OR CAUSING CONCERN TO PARTICIPATING ACFT OR TWR OPERATOR (IF PRESENT); AND PROCEEDED ALONG THE PWR LINES AS PLANNED. 1 HELI BECAME VISIBLE TO ME AS I APCHED THE AHP BUT WAS WELL ABOVE ME AND A SAFE LATERAL DISTANCE FROM MY ACFT. HE CROSSED MY FLT PATH AT A 90 DEG ANGLE WELL ABOVE AND IN FRONT OF ME AND DID NOT APPEAR TO HAVE SEEN ME OR PERCEIVED A CONFLICT. HE DID NOT ALTER COURSE. A SHORT TIME LATER A 'RAMPART 45' CALLED ME ON THE MULTICOM FREQ. I ACKNOWLEDGED THE CALL AND TOLD HIM WHAT I WAS DOING AND REQUESTED ASSISTANCE AND THE VHF FREQ ON WHICH THE HELIS AND TWR (IF PRESENT) WERE OPERATING. SEVERAL MINS LATER HE REPLIED TO MY REPEATED CALLS AND GAVE ME THE FREQ. THIS ACCOMPLISHED NOTHING SINCE MANY MIL FREQS; INCLUDING THIS ONE; ARE BEYOND THE FREQ RANGE OF CIVILIAN RADIOS. AFTER THAT; I FLEW AROUND THE AHP TO AVOID CONFLICT. IN THIS AREA THERE ARE MANY TRAINING FIELDS; SUCH AS THIS ONE; THAT HAVE EXTENSIVE (FREQUENTLY LOW LEVEL) MIL HELIS OPERATING IN WHAT IS PRIMARILY CLASS 'G' AIRSPACE. SINCE THE AIRSPACE DOES NOT REQUIRE RADIO CONTACT; AND FREQS ARE UNAVAILABLE TO THE PUBLIC (AND ARE INCOMPATIBLE ANYWAY); MANY ACFT ROUTINELY FLY OVER AND THROUGH THESE AREAS ON A DAILY BASIS (USUALLY ABOVE THE TFC PATTERN). THIS CREATES A HAZARD TO THE HELI CREW (WHO IS USUALLY A STUDENT PLT) AND TO THE CIVILIAN ACFT THAT COULD ALSO HAVE A STUDENT PLT ABOARD. I RECOMMEND THAT COMPATIBLE FREQS BE MADE AVAILABLE TO THE PUBLIC AND SOME SORT OF 'MINI CLASS D' AIRSPACE BE INSTALLED AROUND THESE AREAS.