B777 relief pilot reports TCAS event in svzm airspace at fl 380 near logon on UL795.

Attributes
ACN	729207
Time
Date	200702
Local Time Of Day	0001 To 0600
Place
Locale Reference	intersection : logon
State Reference	FO
Altitude	msl single value : 38000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : svzm.artcc
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Route In Use	enroute airway : ul795.airway
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : svzm.artcc
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise : enroute altitude change
Person 1
Affiliation	company : air carrier
Function	flight crew : relief pilot
ASRS Report	729207
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas other flight crewa other controllera
Resolutory Action	flight crew : took evasive action
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

10 NM south of logon intersection on airway UL795 at FL380. Opposite traffic climbing from FL370 to FL390; but leveled at FL380 for several mins. Had visual contact; then TCAS gave TA followed by RA. Initial RA was 'descend;' then immediately changed to 'climb; climb now.' I disconnected the autoplt and followed the RA. At FL381.8 the RA was over. I descended back to FL380. We flew 1 NM offset to the right from the centerline of the airway at the time. This gave us an extra layer of protection by providing a little bit of lateral separation; and should be considered for adopting as SOP in south america. Extreme vigilance is required at all times in south america.

Original NASA ASRS Text

Title: B777 RELIEF PILOT REPORTS TCAS EVENT IN SVZM AIRSPACE AT FL 380 NEAR LOGON ON UL795.

Narrative: 10 NM S OF LOGON INTXN ON AIRWAY UL795 AT FL380. OPPOSITE TFC CLBING FROM FL370 TO FL390; BUT LEVELED AT FL380 FOR SEVERAL MINS. HAD VISUAL CONTACT; THEN TCAS GAVE TA FOLLOWED BY RA. INITIAL RA WAS 'DSND;' THEN IMMEDIATELY CHANGED TO 'CLB; CLB NOW.' I DISCONNECTED THE AUTOPLT AND FOLLOWED THE RA. AT FL381.8 THE RA WAS OVER. I DSNDED BACK TO FL380. WE FLEW 1 NM OFFSET TO THE R FROM THE CTRLINE OF THE AIRWAY AT THE TIME. THIS GAVE US AN EXTRA LAYER OF PROTECTION BY PROVIDING A LITTLE BIT OF LATERAL SEPARATION; AND SHOULD BE CONSIDERED FOR ADOPTING AS SOP IN SOUTH AMERICA. EXTREME VIGILANCE IS REQUIRED AT ALL TIMES IN SOUTH AMERICA.

Data retrieved from NASA's ASRS site as of January 2009 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.