Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 7623; Flight Crew Type 1353
Time Pressure; Situational Awareness; Human-Machine Interface; Distraction; Workload; Communication Breakdown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude
Aircraft Equipment Problem Dissipated; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; Flight Crew Became Reoriented
Aircraft; Procedure
Being vectored for the RNAV 13L approach. SKBO in 1L; discontinuity; then ISMUT. Cleared direct ISMUT for the approach; I put ISMUT in 1L and executed. First Officer saw execute light illuminated on the right FMC (not illuminated on the left side). When he pressed execute; we lost both navigation screens and had the TRK message on them. I tried to reinstall the approach (I had BOG VOR in manual and knew we were at a safe altitude). Couldn't reinstall because the FMC's were locked up. We climbed to 14;000 (MSA) and got radar vectors while we figured it out. Controller momentarily confused my voice with that of a female air carrier pilot. This was corrected by the slow annunciation of call sign and flight number by she and I. The FMC's came back online. I installed the approach for the ILS 13R and we landed without incident.
We were given direct BOG VOR approximately 80 NM away from the VOR and descending to 12;000. We were not yet given an approach or runway assignment but planned and briefed the RNAV 13L as the ILS was out of service. Our FMC had BOG a discontinuity and ISMUT for the initial approach to 13L. ISMUT is about the same location as BOG VOR. About 15 NM prior to BOG VOR we were cleared for the RNAV 13L we put ISMUT to 1L and went direct. About the time we were leveling off in LNAV and VNAV PTH I noticed an [execute] light was on on my FMC I told the captain I was going to [execute] it making sure nothing changed as it appeared that it was already navigating to the fix. (After the event we believe only the right FMC [execute] light was illuminated). After I pressed the [execute] light on the right side FMC the magenta line on the MFD blanked out as well as all fixes on both FMCs and a TRK caution appeared on the MFD. The captain immediately tried to reload the approach but 'time out' displayed on the FMC scratchpad. It was unresponsive for about 2 minutes we went to raw data flying direct to the BOG VOR advised ATC we lost our navigation and requested climb to 14;000 and vectors for another approach by the time we began to climb and approach the BOG VOR (getting a vector heading for 13R ILS) we got all functionality back from the FMC. We loaded ILS 13R and executed the approach and landed safely.The controller was busy with a lot of traffic and I know we didn't fully explain our issue as we were busy making sure we never lost our Situational Awareness. I am writing this as I am aware the controllers wanted more information on this event.
A B757 flight crew reported the FMC dumped the SKBO RNAV 13L arrival while in a descent to 12;000 feet. The crew was locked out of the FMC for two minutes. Unable to reload data; they requested radar vectors but then successfully loaded and flew the ILS 13R.