A319
Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance
Aircraft
Enroute ATC issued the following holding instructions due to weather delays at destination:  Hold at MTO; Southwest on the 245 radial; Left Turns; 20 mile legs; maintain FL310 EFC at 2325Z.  We read back the instructions and ATC acknowledged the readback.  I entered the hold in the FMS and the Captain agreed with the entry.  We were already slowed down to Mach .73 (260 KIAS) when the entry was made and I planned to fly the hold at that speed.  Approaching the holding point I noticed that the FMS had drawn a huge race track pattern with a 23 mile diameter turn.  Upon entering the holding pattern; the airplane started a very shallow (approximately 10 degree) bank to enter the pattern.  I mentioned to the Captain that the pattern did not appear right and he suggested to go to managed speed.  I selected managed speed (about 220 KIAS) but that did not make any difference on the pattern size.  I suggested going to heading and tightening the turn because the pattern still looked too wide to me.  The Captain agreed and I did so.  ATC called our call sign but then said to disregard.  Shortly after that ATC gave us a direct turn to a waypoint on the arrival and we proceeded without further incident. This same scenario occurred over a year ago to me on an A319 and I submitted a report.  It was later determined that a software error was causing the very large racetrack patterns being drawn by the FMS and a memo was created for the Airbus read file regarding the issue.  I believe the software bug is back.  Somebody should properly test this software before it gets put in an airplane.  Airbus FMGS software is full of bugs that should have been corrected a long time ago.
A319 First Officer reports the holding pattern created by his aircraft at FL310 has a 23 NM diameter. The aircraft is slowed from 260 KTS to 220 KTS with no change in the pattern. The flight path is finally tightened up using the heading knob but the depicted pattern remains unchanged.