CORP JET HAS LOSS OF RADIO CONTACT; LTSS.

Narrative

SHORTLY AFTER RETURNING TO THE COCKPIT; I BECAME AWARE THE FO WAS QUITE BUSY WITH RADIO COM. WHILE TAKING MY SEAT I NOTICED THAT A HIGHER ALT HAD BEEN SET IN THE ALT SELECT. I QUESTIONED THE SETTING; AND HE EXPLAINED CURACAO HAD GIVEN US FL390 AND A R TURN TO INTERCEPT RBA 010 DEG RADIAL FOR POTENTIALLY CONFLICTING TFC. BUT; CURACAO HAD COME BACK AND AMENDED THE ALT TO REMAIN AT FL370. MOMENTS LATER; TCASII SOUNDED WITH A COMMAND TO 'DSND NOW;' THE IVSI ARC WAS RED DOWN TO 1800 FPM. I IMMEDIATELY TOOK THE ACFT AND EXECUTED A 2000 FPM DSCNT WHILE TURNING R TOWARD OUR INTERCEPT HDG. WE LEVELED FOR A MOMENT AT 36500 FT AFTER RECEIVING 'CLR OF CONFLICT;' AND OBTAINING VISUAL WITH THE TARGET. WE RETURNED TO FL370 AND RPTED THE INCIDENT ALONG WITH CURRENT HDG TO CURACAO. THEY RECLRED US ON RTE TO CARACAS (CCS) AND INFORMED US THAT THE OTHER ACFT (LTT) WAS OUT OF RADIO CONTACT FOR SOME REASON AND HAD BEEN CLRED TO FL390. WE ESTABLISHED CONTACT WITH LTT ON 130.55; AND DISCUSSED IT WITH THEM. THEY EXPLAINED THAT MAIQUETIA CTL (CCS) HAD GIVEN THEM A CLB TO FL390; AND THEY WERE COMPLYING WITH THE CLRNC; BUT WHEN THEY TRIED TO TALK WITH MAIQUETIA CTL; THEY COULD NOT GET A WORD IN AROUND ALL THE SPANISH BEING SPOKEN. IN SUMMARY; OUR TCASII PERFORMED WELL; NO ONE WAS HURT; AND THE LTT EXPERIENCE WITH MAIQUETIA CTL SEEMS TO BE A REGULAR EXPERIENCE DOWN THERE. SUPPLEMENTAL INFO FROM ACN 251030: ALSO DURING CLB NOTICED L FUEL GAUGE WAS READING 1000 LBS LOW. CAPT DECLARED HE HAD THE AIRPLANE AND CTR WHILE ACFT TECHNICIAN AND I WERE TO CHK OUT THE PROB. (I NEVER COMPLETELY LEFT THE FREQ.) AFTER SEVERAL CHKS WE DECIDED THE GAUGE WAS WRONG. AT THIS TIME I FELT WE SHOULD BE TALKING TO SOMEONE BESIDES MAIQUETIA AND STARTED LOOKING FOR A FREQ. ALSO NOTICED OVER ONDAS INTXN TELEPHONE SYMBOL INDICATING FREQ CHANGE. CALLED MAIQUETIA TO REQUEST A CHANGE. AFTER 3 TRIES; HE ANSWERED AND GAVE 128.5. CHKED ON WITH 128.5 (MAIQUETIA) WHO GAVE US 124.1 CURACAO. UPON TRANSFER WE HEARD CURACAO TALKING TO AN ACR ABOUT TFC AND ACR DECLARING THEY HAD THE TFC ON TCASII AND TOOK EVASIVE ACTION TO AVOID IT (US). OFF TO OUR L SIDE WE COULD SEE AN AIRLINER APPROX OUR ALT AND 3- 4 MI. WE THEN CHKED ON WITH CURACAO WHO INFORMED US THAT MAIQUETIA HAD BEEN TRYING TO TRANSFER US SINCE ATONO/AUELO. WE NEVER HEARD THE TRANSFER. IN FACT; AT THAT TIME; HAD REMARKED ON HOW BUSY THE CTLR WAS AND IT ALL BEING IN SPANISH. THIS INCIDENT WAS DEFINITELY FROM A LACK OF COM. ADDED FACTORS BEING SPANISH VERSUS ENGLISH; DISTR FROM THE PAX (I SHOULD HAVE CAUGHT THE FIR BOUNDARY SOONER) AND FATIGUE AND THE FUEL GAUGE. WE NEVER HEARD THE CHANGEOVER AND AFTER SWITCHING TO CURACAO; WONDERED IF MAIQUETIA WAS TOO BUSY OR EXCITED AND KEPT TRYING US IN SPANISH OR TRULY FORGOT US OR WE JUST PLAIN MISSED THE CALL. ALSO ADDED FACTOR WAS THE WRONG FREQ INITIALLY GIVEN BY MAIQUETIA. ANOTHER FACTOR COULD HAVE BEEN FATIGUE. OUR DAY STARTED AT AM00 LCL IN SAN PAOLO; BRAZIL. WE HAD ALREADY FLOWN 6 HRS TO MAIQUETIA FOR A FUEL STOP. WE HAD EXTRA GND TIME THERE DUE TO THE FUEL TRUCK RUNNING DRY. AND ANOTHER THOUGHT -- IF CURACAO KNEW THEY WEREN'T TALKING TO US TO HOLD US DOWN BELOW ACR; WHY DIDN'T THEY TREAT US AS A RADIO FAILURE AND VECTOR ACR BEFORE ACR HAD TO TAKE EVASIVE ACTION?