Narrative:

While flying the intermediate approach segment of the ILS; ATC discontinued our approach and issued non standard missed approach instructions. At 2500 ft and prior to the final approach fix; ATC issued instructions to 'turn 30 deg right and climb/maintain 4000'. The first officer elected to use 'open climb' to 4000 and use heading select to turn the 30 deg right. Unlike the expected 'open climb' response; the airplane pitched up to approx 15 deg without adding power. The airspeed rapidly decayed and alpha floor/toga lock engaged based on the extended trend arrow causing the autopilot to increase pitch further to approx 17.5 up. Airspeed rapidly decayed further to approx 120 knots as the engines increased to full power. To emphasize the quickness of this occurrence ; the first officer was just making his 'go around flaps' callout to which I responded 'no; not at 120 knots' and advised him of autothrust being in toga lock. He reached up; placed the thrust levers in the toga detent and began to disengage the auto thrust. Uncomfortable with the high pitch and low airspeed condition and the time involved with issuing instructions I called 'my aircraft;'; and lowered the pitch to increase airspeed. With airspeed increasing through approx 180 knots I called out flaps 1; up etc. While turning to the assigned heading and climbing to the assigned altitude. The first officer indicated he was ready to resume flying duties. I transferred control to the first officer who at that point when attempting to adjust his map display received the 'set offside range' message indicating an FMGC conflict. Autopilot 2 had remained on throughout the previous events. We 'synced' maps; switched to autopilot 1 and continued to a normal landing. Checking at the gate indicated status 'normal' and both FMGC's appeared to be operating normally.the aircraft ahead (a B737) slowed to a speed below our final approach speed creating the need for a go around. I can only guess that perhaps the actual speed may have been a few knots above the bug when open climb was pulled. Thus delaying the autothrust response until it was too late or perhaps the event occurred at the moment of the FMGC hiccup. I'm unsure what to add here. With varying go around procedures for ILS; ILS prm escape; and two additional RNAV go arounds; I could not fault the first officer for choosing open climb from an ILS while still outside the marker for small turn and climb. I agree it would not have resequenced the waypoints as desired but I never expected a near stall event.

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Original NASA ASRS Text

Title: A320 Captain reports autopilot pitch up; airspeed loss; and Toga Lock during attempted go around at ATC direction. Pilot flying is slow to notice the airspeed loss and Captain assumes control for the recovery. One FMGC locks up during the recovery but all systems appear normal at the gate after landing.

Narrative: While flying the intermediate approach segment of the ILS; ATC discontinued our approach and issued non standard missed approach instructions. At 2500 ft and prior to the final approach fix; ATC issued instructions to 'turn 30 deg right and climb/maintain 4000'. The First Officer elected to use 'open climb' to 4000 and use heading select to turn the 30 deg right. Unlike the expected 'open climb' response; the airplane pitched up to approx 15 deg without adding power. The airspeed rapidly decayed and Alpha Floor/Toga Lock engaged based on the extended trend arrow causing the autopilot to increase pitch further to approx 17.5 up. Airspeed rapidly decayed further to approx 120 knots as the engines increased to full power. To emphasize the quickness of this occurrence ; the First Officer was just making his 'go around flaps' callout to which I responded 'no; not at 120 knots' and advised him of Autothrust being in TOGA lock. He reached up; placed the thrust levers in the TOGA DETENT and began to disengage the auto thrust. Uncomfortable with the high pitch and low airspeed condition and the time involved with issuing instructions I called 'My Aircraft;'; and lowered the pitch to increase airspeed. With airspeed increasing through approx 180 knots I called out flaps 1; up etc. While turning to the assigned heading and climbing to the assigned altitude. The First Officer indicated he was ready to resume flying duties. I transferred control to the First Officer who at that point when attempting to adjust his map display received the 'set offside range' message indicating an FMGC conflict. Autopilot 2 had remained on throughout the previous events. We 'synced' maps; switched to autopilot 1 and continued to a normal landing. Checking at the gate indicated status 'normal' and both FMGC's appeared to be operating normally.The aircraft ahead (a B737) slowed to a speed below our final approach speed creating the need for a go around. I can only guess that perhaps the actual speed may have been a few knots above the bug when open climb was pulled. Thus delaying the Autothrust response until it was too late or perhaps the event occurred at the moment of the FMGC hiccup. I'm unsure what to add here. With varying go around procedures for ILS; ILS PRM escape; and two additional RNAV Go Arounds; I could not fault the First Officer for choosing open climb from an ILS while still outside the marker for small turn and climb. I agree It would not have resequenced the waypoints as desired but I never expected a near stall event.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.