Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Weather / Turbulence
Flight Crew Executed Go Around / Missed Approach; Flight Crew Took Evasive Action
Aircraft; Weather
We were cleared for the ILS DME Runway 07 at MROC and cleared to descend to 7;000 FT on the LOC. About 20 NM from the airport inside LOPEZ descending through 9;000 just about to intercept the glideslope; we received an AURAL WARNING; from EGPWS; TERRAIN; TERRAIN; TERRAIN; PULL UP. We were in weather IMC and rain showers; so the First Officer; immediately performed the escape maneuver; and the warning ceased immediately. We requested a right turn to avoid thunderstorm buildup to the north and climbed initially to 12;000 FT then recleared to 14;000. We were vectored in sequence for another approach with no warning on the second approach. The minimum vectoring altitude where we were; based on raw data was 6;000 FT.
After holding due to weather and aircraft traffic at MROC airport we were on final for the MROC ILS Runway 07 approach. While on the localizer and at approximately 8;000 FT in a rain storm/IMC conditions near the TOMAS Intersection we received a 'terrain-terrain-pull up' aural warning. I was the pilot flying and initiated a mandatory 'escape maneuver climb' due to the IMC conditions. I climbed the aircraft and we eventually leveled off at 14;000 FT with ATC clearance. We returned to holding due to weather/aircraft traffic in the area and then completed an uneventful approach/landing into Runway 07 at MROC.
B737-800 flight crew approaching TOMAS Intersection at 8;000 FT arriving MROC in IMC receives an EGPWS terrain warning and executes the escape maneuver. A second approach flown in a similar manor produces no warning.