HELI TAKES OFF DOWNTOWN HELIPORT AND GETS INTO CLOUDS PREMATURELY.

Narrative

WE WERE DEPARTING FROM THE WEST 30TH STREET HELIPORT (NYC) INTENDING TO FLY TO ALBANY; NY (IFR). THE WX AT LGA WAS RPTED AS 700 FT BROKEN AND 2 MI VISIBILITY. AT APPROX XX00 LCL WE WERE NOTIFIED THAT OUR PAX WAS ENRTE TO THE HELIPORT SO THE CAPT TELEPHONED LGA TWR TO REQUEST OUR IFR CLRNC. IT WAS PUT ON REQUEST AND HE WAS TOLD TO CALL BACK IN 5 MINS. HE CALLED BACK IN 5 MINS; GOT THE CLRNC INFO AND WE ALL BOARDED THE HELI. AS WE WENT THROUGH OUR PRE TKOF CHKLIST; I SAW THE SQUAWK CODE IN THE XPONDER; BUT I DID NOT SEE THE USUAL DEP CTL FREQ OF 126.05. I ASKED THE CAPT 'DO YOU HAVE THE APCH CTL FREQ?' HE SAID 'YES.' I ASKED IF IT WAS THE 124.94 SET AS THE BACKUP FREQ ON THE RADIO. HE AGAIN SAID YES. IT'S AN UNUSUAL FREQ THAT I HAD NEVER SEEN USED BEFORE IN THE NYC AREA. AT LEAST I COULDN'T RECALL IT BEING USED; BUT I SAID TO MYSELF IT MUST BE SOMETHING NEW; MADE FOR LOW ALT HELIS? WE DEPART THE HELIPORT. AT 500-600 FT MSL; I STARTED TO GO INTO THE CLOUD BASES; I DSNDED TO 500-400 FT MSL. THE CAPT WAS TOLD TO CONTACT 124.95 AT THE GEORGE WASHINGTON BRIDGE (ABOUT 4 MI N OF THE HELIPORT). HE WAS WAITING TO MAKE THE CALL. AT ABOUT 1 MI S OF THE BRIDGE; I WAS SEEING FEWER GND LIGHTS ON THE MANHATTAN SHORELINE. I WENT INADVERTENT IMC AT ABOUT 500 FT MSL. I KNEW THAT THE BRIDGE WAS 1 MI AHEAD AND THAT I MUST HAVE 900-1000 FT TO CLR THE BRIDGE STANCHIONS AND ADJACENT BUILDING. I CLBED TO 1000 FT. IN THE MEANTIME; THE CAPT CALLS ON 124.95 AND AFTER ABOUT 2 XMISSIONS; WE FIND THAT WE MUST NOW GO TO 126.05 TO GET DEP CTL. WE DID THIS AND IT TOOK ANOTHER 2 OR 3 XMISSIONS BEFORE WE WERE CLRED IFR TO FLY 040 DEGS AND CLB TO 2000 FT. AT THIS POINT; THINGS WERE NORMAL; BUT PRIOR TO THIS WE WERE IN LGA AIRSPACE AND INADVERTENT IMC (NOT A GOOD SIT). AS THE PF OF THE HELI; AND DOING WHAT I HAD DONE MANY TIMES BEFORE; I HAD A MINDSET THAT THE CTLR ON 124.95 WAS GOING TO GIVE US A HDG AND ALT ALMOST IMMEDIATELY (SINCE WE HAD JUST TOLD THEM ON THE TELEPHONE THAT WE WERE LEAVING THE HELIPORT). I DID NOT TAKE THE CAUTIOUS APCH OF FLYING VERY SLOWLY AND I WAS NOT MENTALLY PREPARED TO DO A 180 DEG TURN AT 300 FT DURING THIS NIGHT FLT. HOWEVER; I WILL NOT BE CAUGHT THIS WAY AGAIN!