B777-200
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 19910
Time Pressure; Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude
Flight Crew Took Evasive Action; Flight Crew Returned To Clearance
Aircraft
Working SBGR Approach Control during vectors for ILS 9R with descent clearance to 5;500 FT and passing approximately 6;500 FT a 'climb now' RA was received. The RA target indicated 200 FT below at 12 to 1 o'clock. The autopilot was disconnected and climb was initiated. ATC was advised that we were climbing and responding to an RA. ATC was very busy with much frequency congestion and did not acknowledge our transmission. Shortly after initiating the climb all TCAS information stopped. There was never any vertical speed guidance during the event other than a momentary indication on PFD and a clear of conflict message was never given. We were in visual conditions during the event and there was no visual contact with any aircraft traffic nor did we receive a TCAS TA advisory prior to the RA. After all TCAS warnings stopped a slow descent back to our original cleared altitude was started and we requested further descent from ATC and continued the approach to landing. Given the conflicting indications that we had I feel this RA was possibly a TCAS anomaly possibly from another aircraft transponder transmitting erroneous information.
During descent; we received a 'CLIMB NOW' TCAS RA which showed traffic on the NAV DISPLAY at 12 o'clock and 200 FT below. The Captain (at controls) disconnected the autopilot and initiated an immediate climb as SBGR Approach Control was advised by the First Officer that our aircraft was responding to a TCAS RA and climbing. No 'CLEAR OF CONFLICT' annunciation was heard from the TCAS system and there was no visual indication of traffic at any time during the event. SBGR Approach Control never identified any traffic in our area. There was no TA Advisory prior to the 'CLIMB NOW' TCAS RA and all TCAS indications stopped after the initial RA warning.
A B777 Crew responded to a TCAS RA from traffic at 12 o'clock 200 FT low while on approach to SBGR but the warning was apparently false and may have been a null bus fault.