Date: 201510
Local time of day: 0601-1200
Location: MCO.Airport, FL
Aircraft: A321
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B MCO
ATC / advisory: Tower MCO
Aircraft component: Autothrottle/Speed Control
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: I was advised after the fact that we had a slat over speed of eleven knots. I did write up a five knot over speed in the Aircraft Maintenance Log (AML). FO was the flying pilot. Aircraft leveled at four thousand feet on downwind to 18R. Left engine stayed in idle while right engine accelerated. Soon thereafter; red ECAM- auto thrust lock. Accomplished ECAM procedure which quickly accelerated left engine to match the right engine which was developing more thrust due to left engine at idle. Due to all this rapid acceleration; speed went above slat speed. I quickly retracted the slats. During all this; we also deviated three hundred feet off our altitude when the autopilot was turned off.


Second narrative: FO was Pilot Flying (PF) on the last leg of a lengthy three-leg duty day. Takeoff; climb; cruise; descent and initial approach were uneventful. Entering downwind at MCO and descending to 4;000 feet MSL; flaps condition 1; all normal automation engaged; just prior to leveling off at 4;000 feet the aircraft ECAM system alarmed an auto thrust lock on the #1 engine and an asymmetric thrust condition presented itself. Note: this was not an 'amber' ECAM indication with single chime normally associated with one or both throttle being out of their detents. This was a 'red' ECAM annunciation with a master warn on the glare shield; repetitive chime; and an associated ECAM action. The #1 engine appeared to be at a speed somewhere near idle at the time of the alarm.The captain announced the ECAM message; assigned me to continue as PF and maintain aircraft control; and I acknowledged. The CA assumed control of the throttles to perform the ECAM actions while I flew. We were perhaps 400-500 feet from level off and I had a handful of airplane my attention was initially focused on the Primary Flight Display (PFD). The CA announced the ECAM steps; and moved the #1 throttle in accordance with the procedure. In the course of the #1 throttle being reset the #1 engine roared back to life (my words) and the aircraft rapidly increased airspeed; resulting in a momentary flap over speed with associated annunciation from the ECAM. FO shed the autopilot and manually closed both throttles to idle and assumed manual control of the airplane. Both throttles responded symmetrically. The CA retracted the flaps. Once the aircraft settled down the pilot team re-established a flaps 3 landing configuration and executed a manually-flown; right-seat ILS approach and landing to MCO with no further developments.


Synopsis: A321 flight crew experiences a red ECAM- auto thrust lock; during level off at 4;000 feet. The Captain performs the ECAM actions which causes a rapid increase in thrust and an over speed of the slats.