Date: 201310
Local time of day: 0001-0600
Location: SBAZ.ARTCC, FO
Flight conditions: IMC
Weather elements / visibility: Turbulence; Thunderstorm; Icing
Light: Night
Aircraft: B767 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center SBAZ
Second aircraft: Any Unknown or Unlisted Aircraft Manufacturer
Aircraft component: Traffic Collision Avoidance System (TCAS)
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying; Relief Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Confusion
Anomaly: Aircraft Equipment Problem Critical; Conflict NMAC
Detector: Automation Aircraft RA; Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Procedure; Aircraft; Human Factors
Primary problem: Ambiguous

Narrative: This flight had an approximate flight time of 11 hours and 30 minutes. In this flight we operate with augmented crews and we further divide the flight between the pilots to rest accordingly. We came to the cockpit from a 5 hour break very fresh and rested; and about 30 minutes after being in the cockpit we approached some weather on airway UM527 in Brazilian airspace. We were at FL360 with a heading of 240 approximately and requested a heading of 190 for 20 miles to deviate. In the process of the deviation I saw two [targets] at our 10 o' clock approximately 30 miles or so. I told the Captain that we had two [targets]; one at FL360 (same level) and one at FL380. We deviated to a 190 heading but immediately turned to our original heading of 240 because we were head on with the other conflicting aircraft. In the process we realized that they were on an apparent heading of 330. Since the traffic was closing in very rapidly I questioned ATC about traffic at 10 o' clock same level. ATC responded 'XXX descend to FL350 NOW' to which I respond and complied; and then ATC issued another instruction to the conflicting aircraft: 'XXX maintain FL360'; which then responds (OK; maintaining 360). Before even having a TA we left FL360 and started a descent to FL350 (autopilot was engaged) using V/S. When descending we had a TA (Traffic; traffic); we noted that the other aircraft had LEFT FL360 and started a descent to FL350 WITHOUT ATC CLEARANCE and BEFORE the TCAS TA (In this moment we turned all of our lights on). In no time we got the RA; to which we were instructed to DESCEND AURALLY BUT the ADI instructions told us to climb which created confusion!! (Per manufacturer procedures the autopilot and autothrottles were disconnected); we increased pitch (THE TCAS then ISSUES A CLB) accordingly (since we were descending) and when we were about to get out of the RED ADI TCAS AREA; we got a DESCEND command to which we tried to accommodate and then; in less then 1 second we got a CLIMB command again. Given the amount of conflicting TCAS commands then we started a climbing turn to which we got the BANK ANGLE advisory. In the mean time we saw (We were in IMC and icing conditions) the conflicting aircraft strobe lights VERY CLOSE. Approximate miss distance 100 FT vertical and 100 FT lateral. Once we got the clear of conflict advisory; I called ATC told them 'XXX we had a TCAS RA; CLEAR OF CONFLICT; resuming FL350'; ATC then cleared us to climb to FL360. We engaged the autopilot and autothrottles and resumed FL360. The ATC Control told us 'I'm sorry' and the conflicting aircraft didn't even report having an RA. I believe the contributing factors to this incident were:1. Having two intersecting airways (conflicting direction) which require pilots to maintain the same FL (either even or odd). In this case we where on a 240 heading and the other aircraft was on a 330 heading (we were both required to maintain EVEN FL).2. Possibly due to the time of the day (morning); ATC was tired and missed the fact that he had two aircraft at the same level; on collision course.3. The weather enroute placed especial difficulty in visually identifying the traffic (IMC conditions).4. The fact that the conflicting aircraft never contacted ATC to inform that they had an aircraft at the same level (we were the only ones questioning ATC).5. The fact that the other aircraft left FL360 for FL350 WITHOUT ATC clearance AFTER being instructed to maintain FL360.6. The fact that we were already in a descent and then got a DESCEND aural command; BUT the ADI showed that we needed to CLIMB. We decided to follow the ADI commands (after approximately of 1 second of confusion).7. The lack of airmanship from the other aircraft to try to evade our aircraft and communicate the incident to the corresponding ATC frequency.8. The multiple RA commands (climb and descend) in a short period of time; due to the possibility that the other aircraft was also trying to accommodateto conflicting RA's as well.




Synopsis: B767 First Officer reports a NMAC at FL350 near ROLUT in Brazilian airspace. The approaching target was detected by the reporter at FL360 and ATC was queried. The reporter is issued a descent to FL350 and the other aircraft is instructed to remain at FL360 but descends. The TCAS RA showed conflicting information initially; with the voice calling for a descent and the  display indicating a climb. Several RA reversals occur resulting in the NMAC. The Controller involved accepted responsibility for the initial conflict.