Air carrier overwater flight unable to contact ATC is alerted to traffic by TCASII.

Attributes
ACN	179861
Time
Date	199106
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : nav
State Reference	FO
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : spg
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute airway : mmid enroute other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	cruise other
Route In Use	enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 280 flight time total : 20000 flight time type : 5000
ASRS Report	179861
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	Other
Miss Distance	horizontal : 49400 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other

Narrative:

Air carrier charter flight slc-cun-specifically mam (ats) routing mid and on to cun. Monterey control handed us off to merida control at abbot fix. We made numerous calls to merida and although we could hear merida conversing in spanish with a spanish carrier, we couldn't get them to respond to our calls. We had been at FL370 for some time prior to entering mexican airspace. We continued to call every 2 or 3 mins. As we approached desco fix, our TCAS system annunciated 'traffic, traffic.' an air carrier Y flight passed our 12 O'clock at 8-9 NM co-altitude. It wasn't a near miss, but certainly closer than it should have been. When we reported desco this time, merida answered (air carrier Y reported desco just prior, I believe). Merida, in a very routine fashion, instructed us to descend to FL350. We discussed the situation with air carrier Y. Air carrier Y flight wasn't sure if possibly they had misunderstood their clearance or not. We both kind of agreed it was probably merida's error, and saw no reason to pursue it further as it wasn't that close. TCAS is a godsend.

Original NASA ASRS Text

Title: ACR OVERWATER FLT UNABLE TO CONTACT ATC IS ALERTED TO TRAFFIC BY TCASII.

Narrative: ACR CHARTER FLT SLC-CUN-SPECIFICALLY MAM (ATS) RTING MID AND ON TO CUN. MONTEREY CTL HANDED US OFF TO MERIDA CTL AT ABBOT FIX. WE MADE NUMEROUS CALLS TO MERIDA AND ALTHOUGH WE COULD HEAR MERIDA CONVERSING IN SPANISH WITH A SPANISH CARRIER, WE COULDN'T GET THEM TO RESPOND TO OUR CALLS. WE HAD BEEN AT FL370 FOR SOME TIME PRIOR TO ENTERING MEXICAN AIRSPACE. WE CONTINUED TO CALL EVERY 2 OR 3 MINS. AS WE APCHED DESCO FIX, OUR TCAS SYS ANNUNCIATED 'TFC, TFC.' AN ACR Y FLT PASSED OUR 12 O'CLOCK AT 8-9 NM CO-ALT. IT WASN'T A NEAR MISS, BUT CERTAINLY CLOSER THAN IT SHOULD HAVE BEEN. WHEN WE RPTED DESCO THIS TIME, MERIDA ANSWERED (ACR Y RPTED DESCO JUST PRIOR, I BELIEVE). MERIDA, IN A VERY ROUTINE FASHION, INSTRUCTED US TO DSND TO FL350. WE DISCUSSED THE SITUATION WITH ACR Y. ACR Y FLT WASN'T SURE IF POSSIBLY THEY HAD MISUNDERSTOOD THEIR CLRNC OR NOT. WE BOTH KIND OF AGREED IT WAS PROBABLY MERIDA'S ERROR, AND SAW NO REASON TO PURSUE IT FURTHER AS IT WASN'T THAT CLOSE. TCAS IS A GODSEND.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.