A319 captain reports autothrust operating inappropriately during visual approach to dca. A thrust ad...

Attributes
ACN	868256
Time
Date	200901
Local Time Of Day	1801-2400
Place
Locale Reference	DCA.Airport
State Reference	DC
Environment
Flight Conditions	VMC
Light	Night
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 Not Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Engineer Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 188 Flight Crew Total 20619 Flight Crew Type 4830
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Cleared for mt. Vernon visual approach to rwy 1 at dca; autopilot off; both flight directors off as per company procedures. Approach mode had been activated and confirmed. On profile at approximately 180kts; flaps 2. Selected managed speed upon command of pilot flying. Airspeed bug changed to magenta and drove to 131 kts. This was off scale low so we got a 131 at the bottom of the airspeed scale (vapp on FMGC was 129). Extended gear on first officer's command. Thrust started to increase slowly for 1 or 2 seconds; then more rapidly. I was pilot monitoring so I checked FMA. We were in speed mode with magenta 131 airspeed bug. Thrust should have gone to idle to slow to 131; but was increasing. First officer disconnected autothrust to prevent flap overspeed and used manual thrust to an uneventful landing. First officer and I have been on the airbus for many years and could not explain why this happened. It has been our experience; and common knowledge on the line that as our aircraft age; it seems some aircraft do not do as good of a job at holding airspeed as they used to; both in autothrust speed mode and autopilot pitch mode. I can only assume this was a mechanical malfunction.

Original NASA ASRS Text

Title: A319 Captain reports Autothrust operating inappropriately during visual approach to DCA. A thrust addition occurs with aircraft speed above magenta speed bug setting of 131 knots. Autothrust is switched off and normal landing ensues.

Narrative: Cleared for Mt. Vernon Visual Approach to Rwy 1 at DCA; Autopilot off; both Flight Directors off as per company procedures. Approach mode had been activated and confirmed. On profile at approximately 180kts; Flaps 2. Selected managed speed upon command of Pilot Flying. Airspeed bug changed to magenta and drove to 131 kts. This was off scale low so we got a 131 at the bottom of the airspeed scale (Vapp on FMGC was 129). Extended gear on F/O's command. Thrust started to increase slowly for 1 or 2 seconds; then more rapidly. I was Pilot Monitoring so I checked FMA. We were in Speed mode with magenta 131 airspeed bug. Thrust should have gone to idle to slow to 131; but was increasing. F/O disconnected Autothrust to prevent flap overspeed and used manual thrust to an uneventful landing. F/O and I have been on the Airbus for many years and could not explain why this happened. It has been our experience; and common knowledge on the line that as our aircraft age; it seems some aircraft do not do as good of a job at holding airspeed as they used to; both in autothrust speed mode and autopilot pitch mode. I can only assume this was a mechanical malfunction.

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.

A319 captain reports autothrust operating inappropriately during visual approach to dca. A thrust addition occurs with aircraft speed above magenta speed bug setting of 131 knots. Autothrust is switched off and normal landing ensues.