An A319 captain reported that his current aircraft and another A319 the week before experienced an F...

Attributes
ACN	865830
Time
Date	200912
Local Time Of Day	1201-1800
Place
Locale Reference	SFO.Airport
State Reference	CA
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Component
Aircraft Component	Autoland
Person 1
Function	Captain Instructor Pilot Not Flying
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 20000 Flight Crew Type 8000
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Weather in sfo required full ILS to runway 28R. With autopilot on and localizer and GS captured; passing approximately 4000 ft the FMGC approach mode down graded from CAT3 dual to CAT2 with the triple click alert. There were no ecams and no indication on status page or on either the pdf or nd. About 30sec later CAT3 dual came back up. The reason I'm writing bring this is last week a flight to sfo on a different nose number the exact same thing happened at approximately same point at the same airport on the same approach with almost the same weather. This leads me to believe that there may be some form of outside interference affecting the approach capabilities of our 319s.

Original NASA ASRS Text

Title: An A319 Captain reported that his current aircraft and another A319 the week before experienced an FMGC Autoland CAT III Dual to CAT II downgrade on approach to SFO Runway 28R at the same location. Very shortly thereafter the Autoland returned to CAT III.

Narrative: Weather in SFO required full ILS to Runway 28R. With autopilot ON and LOC and GS captured; passing approximately 4000 ft the FMGC Approach Mode down graded from CAT3 DUAL to CAT2 with the triple click alert. There were no ECAMs and no indication on status page or on either the PDF or ND. About 30sec later CAT3 DUAL came back up. The reason I'm writing bring this is last week a flight to SFO on a different nose number the exact same thing happened at approximately same point at the same airport on the same approach with almost the same weather. This leads me to believe that there may be some form of outside interference affecting the approach capabilities of our 319s.

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.

An A319 captain reported that his current aircraft and another A319 the week before experienced an FMGC autoland CAT III dual to CAT ii downgrade on approach to sfo runway 28R at the same location. Very shortly thereafter the autoland returned to CAT III.