A319
Flight Crew Total 20000
Situational Awareness
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Unstabilized Approach
Flight Crew Executed Go Around / Missed Approach
ATC Equipment / Nav Facility / Buildings; Aircraft
Cleared for the approach at SAP/MHLM ILS Z 22 approximately 2;500 ft to 3000 ft slightly above the GS (Glideslope); with the ILS armed and autopilot on; speed 160-170 kts; configuration was gear down; flaps setting at 3 aircraft stable. FO (First Officer) flying.The aircraft pitched down sharply; went below the GS then pitched up sharply and went into TOGA (Takeoff Go Around) lock mode. FO disconnected the autopilot and reduced the pitch at which point the flap over-speed warning came on; I brought the flaps one notch up and stopped the warning. FO disconnected the auto-thrust and we executed a GA. The autopilot and auto-thrust were eventually reengaged and the landing was normal. Autopilot was disconnected at 1;000 ft on final. The event went very fast and only took seconds. It felt as if an anomaly of the GS signal occurred; the nose pitched down and when the signal reappeared the aircraft pitched up sharply to regain it which caused a high angle of attack that triggered the TOGA lock. At that point the FO disconnected the autopilot and auto throttles.The event was very quick. We went from being in a relatively stable condition to low and high pitch angles very fast. I feel the PM did the proper thing by disconnecting the autopilot and the auto-throttles and going around; while I brought the flaps up. SAP approach tends to keep arriving aircraft high. Intercepting the GS from below is probably best. We were above the GS and that might have caused an exaggerated pitch down with the capture of the signal. I still suspect an interruption of the GS signal might have occurred.
A319 First Officer reported a sharp pitch down then up by the autopilot as the glideslope is captured during approach to Runway 22 at MHLM. Auto thrust goes into TOGA lock and a go around is initiated and a flap over speed occurs. Auto flight and auto thrust are disconnected and the next approach is successful.