B777-200
Aircraft Equipment Problem Critical; Deviation - Speed All Types; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Aircraft Equipment Problem Dissipated; Flight Crew Took Evasive Action
Aircraft; Incorrect / Not Installed / Unavailable Part
I was the Relief Pilot observing Captain takeoff. At approximately 1;800 FT while accelerating from a flaps 15 takeoff and on vectors (120 degrees) for the departure; we received an RA with no prior TA warning. First was 'Monitor Vertical Speed' followed by 'Descend; Descend.' The Captain complied perfectly with the RA. I saw the red dot on the MFD directly on the nose with a +2 then +3 on the CA display. I immediately switched my scan to outside the aircraft to try and acquire visual contact with the traffic. While there were some scattered clouds around it was a mostly clear evening. I noticed no traffic. I scanned back inside where the red RA marker was still on the nose of the aircraft as we reached what I thought was around 1;400 FT. We then received a GPWS warning of 'DON'T SINK; DON'T SINK.' The Captain leveled the plane off and the RA disappeared with NO clear of traffic cue. Just prior to the event; the First Officer was changed from Tower to Departure Control. As soon as the RA disappeared he contacted Departure and advised we were responding to an RA. Departure notified us that he had NO traffic in our area and that the minimum vectoring altitude in the area was 1;800 FT. With both the RA and GPWS now over we resumed our climb to 5;000 FT and then 16;000 FT. During the event with the aircraft in VNAV climb 1 and the speed bug on 250; we immediately accelerated from approx 175 KTS to 245 KTS. Well exceeding the flap 15 speed limit of 215 KTS by roughly 30 KTS. After climbing through 10;000 FT the First Officer asked me to check back several weeks in the logbook as he remembered hearing of a similar incident reported on a B777. There I found a similar incident written up almost identical to the event we had just experienced. Erroneous RA departing out of 1;800 FT. That write up was a repeat of another event that was no longer in the logbook pages; but the previous write up detailed that it was identical to the earlier event also. So we know at least 3 times this aircraft has developed a potentially unsafe condition due to system failure. After discussing the situation and the event we had just experienced; all three pilots determined that we felt safe with the aircraft and decided to continue on. The Captain and First Officer said they would contact Maintenance and Dispatch just to make sure we were not missing anything and I went on my rest break. The remainder of the flight continued without incident. We are trained as pilots to comply with an RA above all else except GPWS warning and ground contact. There is no time for decision making unless the traffic causing the RA is insight on a VFR day. This is a system pilots must have confidence in. This aircraft has now put at least 3 crews in some degree of jeopardy by detecting a false target at low altitude and descending the aircraft toward terrain. Maintenance had changed out most of the TCAS components and yet the situation developed again. To avoid the problem again; the cause of the malfunction must be identified and fixed. The flap overspeed was a secondary event and could not be avoided due the priority of the crew to avoid a traffic collision. The event happened so fast that there was no time to monitor speed and call for flap retraction. Even if the flaps had been selected all the way up immediately (which would have been improper) both the flap 15 and flap 5 speeds of 215 and 235 would have been exceeded before the flaps had physically traveled up the next setting.
During takeoff at approximately 1;800 FT AGL; TCAS commanded a descend now RA. I was pilot flying; and immediately complied with RA and First Officer advised ATC. Autopilot was not engaged. Weather was night VMC. Just before RA act had assigned a 120 heading that we were on. TCAS commanded an aggressive descent (approximately 15 degrees nose down) and showed RED traffic symbol on nose of aircraft display. I pushed over as far as I safely could due to the altitude and terrain (buildings). RA went away at about 1;200 FT when replaced by GPWS descent rate command. No clear of conflict was ever received. I recovered to normal climbout and we again advised ATC. During maneuver speed inadvertently exceeded 15 flap limit and went to 247 KTS before recovering to climb. Speed at no time exceeded 250 KTS. On both contacts ATC advised no traffic conflicts on radar. We entered both the apparently false RA and the flap over speed in logbook; advised Dispatch and Maintenance via radio and with their concurrence continued on to destination without further incident. After further review of the log; aircraft had 2 previous events that were almost identical. One was 5 days before and still in the book; and it referenced a previous event that was not in the book. I will be more diligent in going further back in the log for history in the future. Throttle reduction would have reduced the flap overspeed; however in the heat of battle it became secondary. Too low an energy/spool up state could also have been bad in the GPWS recovery. All in all it was a very bad situation that required immediate TCAS avoidance in a bad spot. The RA was displayed as real in all ways and could not be overlooked even with ATC advising no traffic. I feel that my crew and I reacted in the safest possible way that we could with the information that we had at the time.
B777 flight crew experiences a TCAS RA at 1;800 FT on departure and complies with the RA to descend; causing a flap overspeed. At 1;200 FT the RA stops and is replaced by a GPWS 'Don't Sink' warning. ATC advises that there is no traffic in the area. The crew learns that the aircraft has a history of similar false warnings and the flight continues to destination.