A319 captain experiences unexpected auto thrust command for climb thrust during approach. Auto thrus...

Narrative:

We were on a visual approach and the fmcg 'approach perf' page had been 'activated and confirmed' the speed bug was set at 170kts. I disconnected the a/P and left the a/T on. I was at flaps 1 and we were about 4 miles from the outer marker. I was looking outside to orient myself with the location of the traffic ahead on the same approach. I took my hands off of the throttles to adjust the volume of my headset. All of the sudden the engines spooled up and I looked at the airspeed and it was increasing rapidly. At the same time the first officer reached over an slammed the throttles to idle. Being in a descent and the throttles going to full power; the airspeed was rapidly increasing to near the barber pole. We did not over speed the flaps. In manual; the throttles worked as advertised. I wondered if that was a intermittent glitch. I pushed the a/T button and advanced the throttles to cl detent to see what would happen. Immediately the tla's went to max and the engines started to spool up. I immediately disconnected the a/T's and flew the rest of the approach in manual throttles with no further problems. A mechanic met us at the gate and we explained the situation. I have never seen the a/T's do this before. The wind at the time was approx. 020@12kts

Original NASA ASRS Text

Title: A319 Captain experiences unexpected auto thrust command for climb thrust during approach. Auto thrust is disconnected and speed stabilized. When auto thrust is re-engaged as a test; the results are the same.

Narrative: We were on a visual approach and the FMCG 'approach perf' page had been 'activated and confirmed' the speed bug was set at 170kts. I disconnected the A/P and left the A/T on. I was at flaps 1 and we were about 4 miles from the outer marker. I was looking outside to orient myself with the location of the traffic ahead on the same approach. I took my hands off of the throttles to adjust the volume of my headset. All of the sudden the engines spooled up and I looked at the airspeed and it was increasing rapidly. At the same time the First Officer reached over an slammed the throttles to idle. Being in a descent and the throttles going to full power; the airspeed was rapidly increasing to near the barber pole. We did NOT over speed the flaps. In manual; the throttles worked as advertised. I wondered if that was a intermittent glitch. I pushed the A/T button and advanced the throttles to CL detent to see what would happen. Immediately the TLA's went to max and the engines started to spool up. I immediately disconnected the A/T's and flew the rest of the approach in manual throttles with no further problems. A Mechanic met us at the gate and we explained the situation. I have never seen the A/T's do this before. The wind at the time was approx. 020@12kts

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.

Attributes
ACN	857468
Time
Date	200910
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Autothrottle/Speed Control
Person 1
Function	Pilot Flying Captain
Experience	Flight Crew Last 90 Days 250 Flight Crew Total 15000 Flight Crew Type 6400
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Speed All Types

A319 captain experiences unexpected auto thrust command for climb thrust during approach. Auto thrust is disconnected and speed stabilized. When auto thrust is re-engaged as a test; the results are the same.