MLG ON DSCNT UNABLE CONTACT APCH OR TWR DUE ATC RADIO FAILURE. THEN HAS TCASII RA.

Narrative

OUR FLT WAS HANDED OFF FROM ZNY TO LGA APCH CTL (120.4). CONTACT CLRNC WAS TO DSND AND MAINTAIN 4000 FT AND PROCEED DIRECT TO THE LGA VOR. ATTEMPTED TO MAKE CONTACT WITH APCH CTL; AS WE WERE JUST S OF THE MASPETH TANKS. NO CONTACT WAS MADE. WE ATTEMPTED TO CONTACT LGA CTL TWR (118.7) BUT ALSO NO RESPONSE. OTHER ACFT COULD BE HEARD; BUT ALSO NO RESPONSE BY ATC. THE CAPT AND I BEGAN DISCUSSING ENTERING HOLDING. I WAS ABLE TO CONTACT LGA GND CTL (121.7) AND ADVISED OUR POS AND ALT. WAS ADVISED BY LGA GND CTL THAT LGA CTLR TWR HAD EXPERIENCED A TOTAL ELECTRICAL PWR FAILURE. WAS TOLD TO STANDBY ON FREQ FOR APPROPRIATE FREQ. WE WERE STILL MONITORING 120.4 AT THIS TIME; THE TCASII ISSUED A TA. I LOOKED OUTSIDE AND MADE VISUAL CONTACT WITH THE TFC; WHICH WAS AT OUR 1130 TO 12 O'CLOCK POS. THE TARGET PAINTED SOME 5-8 MI FROM US. THE TA MATURED INTO AN RA WITH 'CLB' COMMAND. WE CLBED TO 4800 FT AS THE TFC PASSED BY US. LGA GND CTL CONTACTED OUR FLT AND HANDED US OFF TO 120.55. WE WERE GIVEN HDG AND ALT VECTORS ONTO A VISUAL APCH TO RWY 22. WAS HANDED OFF TO AND MADE CONTACT WITH LGA CTL TWR. A NORMAL LNDG WAS MADE.