Widebody; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Communication Breakdown; Confusion; Distraction; Workload; Fatigue
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Environment - Non Weather Related; Airport; Procedure; Weather
On arrival into SKBO we received a GPWS Terrain and 'Pull Up' verbal warning. We had received the ATIS for SKBO advertising an arrival on 31R. Prior to descent we planned and briefed for this unusual night time arrival. Final descent point was planned to cross BOG VOR at 190/12;000 FT and was programmed in the FMC. We were turned over to Approach Control about 40 miles from BOG VOR and I asked for the planned approach. Was advised now to expect Runway 13L and we re-briefed and bugged for this new approach. There was no mention of a change in weather. Still reported as few at 2;500 and 8;000 meters; wind 1 KT. We were then cleared direct to the BOG VOR and cleared for the approach. I programmed the new approach kept the crossing restriction at BOG of 190/12;000 FT and then to the IAF which was 10;000A and next fix at 10;000. While continuing the descent for the approach; autopilot on; LNAV VNAV engaged; and MCP altitude set at 10;000 for last hard fix before glideslope intercept. Just prior to the BOG VOR we were advised that the runway RVR was now 250 meters and asked what our intentions were. I advised that we would like to continue the approach and we were advised to contact the Tower. As I was changing to Tower and confirming what we needed to complete the approach we received the GPWS warning and initiated the recovery procedure; autopilot off; max power and pitch up. The Tower also advised that we had low altitude warning while in the recovery. We completed the recovery and climbed to 13;000 FT as directed and entered holding at the BOG VOR. We remained in holding until they reconfigured the airport for CAT II operations where we completed the landing. The aircraft was in VNAV with the crossing restrictions and should not have left the 12;000 FT altitude the First Officer stated he noticed the deviation at about 11;000 FT and initiated the recovery technique. I observed the descent stopped at 10;600 and over the top of the BOG VOR. Have the GPWS not activated I would not of noted the deviation. I was tasked saturated at the moment but; prior to head down I verified altitude and crossing restrictions. [I am] at a loss as to [why we had the] deviation; unless at some point FLCH was activated or we had an autopilot malfunction. The First Officer stated he was confirming approach information for full ILS versus a visual approach and had verified aircraft programming prior to looking at chart. The only way I know to prevent this would be stop putting lowest descent altitude on the arrival into the MCP. This may have prevented the aircraft from descending below 12;000; if FLCH had mistakenly been pushed. This would cause other problems on many other approaches. We had briefed multiple times the crossing restriction at BOG and the high terrain in the area and verified that the FMC was programmed correctly. I believe this was a case of saturation and the GPWS did its job providing a warning; and CFIT training prevented [what] could have been an accident.
Just prior to the BOG VOR we were advised that the runway RVR was now 250 meters and moving in and out. ATC asked what our intentions were. The Captain advised that we would like to continue the approach and we were told to contact the Tower. I was re-reading the approach plate for clarification and as I glanced up to verify our position I noticed the altitude to be 11;000 over the BOG VOR; which confused me for a moment until it started flashing Amber. I was about to initiate an altitude correction when the GPWS terrain warning sound. I immediately initiated the recovery procedure; autopilot off; max power and pitch up with the Captain assisting with full power on the thrust levers as I had my seat back a bit while reading the approach plate. The Tower also advised that we had low altitude warning while in the recovery. We completed the recovery and climbed to 13;000 FT as directed and entered holding at the BOG VOR. We remained in holding until they reconfigured the airport for CAT II operations where the Captain took control and we completed the landing safely. This was only my second flight into SKBO and the last being a couple of years ago in good weather; daytime. I must say; along of being somewhat fatigued I was a bit behind the power curve (distracted) trying to decipher the weather; keep situational awareness; understand what the Controller was actually saying and wanting. I believe this was a case of fatigue and last minute saturation and the GPWS did its job providing a warning; and CFIT training prevented [this] could have been a preventable accident.
An air carrier crew on the SKBO Runway 13L ILS; executed the escape maneuver prior to BOG after the EGPWS TERRAIN warning sounded when the crew failed to recognize that the aircraft did not level at 12;000 FT.