Date: 201309
Local time of day: 1201-1800
Location: ZFW.ARTCC, TX
Flight conditions: Marginal
Weather elements / visibility: Thunderstorm; Turbulence
Light: Daylight
Aircraft: A321
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZFW
Aircraft component: FMS/FMC
Component problem: Design
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew; Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance; Flight Crew FLC Overrode Automation; Flight Crew Became Reoriented
Contributing factors: Aircraft; Weather; Human Factors
Primary problem: Ambiguous

Narrative: Due to DFW closure; we were issued holding at the WEIRS intersection.  This intersection was not on our arrival.  I programmed the hold as a database hold.  We allowed the FMS to enter the hold.  The aircraft wanted to slow to a holding speed of 233.  This speed put us below the Vls or right at Vls.  The Pilot Flying and I agreed that this was too slow a speed to hold at based on our altitude; and weather conditions.  The aircraft entered the hold; but seemed to exceed the holding area; based on our conversation with ATC.  After two turns in the hold; we decided that due to the approaching weather on the outbound leg; we needed to vacate the holding fix.  We were then issued a hold at the HERRI Intersection.  The hold was entered as a database hold.  We proceeded to the new hold and allowed the FMS to enter the hold.  It appeared that the entry was parallel.  The aircraft completed parallel entry hold at a distance of 37 NM from the fix.  ATC inquired on several occasions as to confirm if we had the correct fix and turns in the hold.  I read back the correct ATC holding clearance.  Both the Pilot Flying and I confirmed three times the correct holding in the FMGC.  The Pilot Flying had to go into heading mode on two occasions to keep the aircraft in the holding protective area.  Because of the slow programmed holding speed and weather conditions; flying at a higher speed caused us to exceed the ATC holding airspace.  This also increased the turn radius and holding pattern; which led to ATC questioning our holding procedures.


Second narrative: There was a large line of moderate to severe thunderstorms in the Dallas/Fort Worth area. As we were navigating around thunderstorms (south of DFW); Fort Worth Center advised us that approaches had been stopped and that we would be required to hold at a nearby fix (WEIRS intersection). We slowed and started to hold at WEIRD until a thunderstorm cell interfered with the holding pattern. We were then cleared to the 'HERRI' fix and instructed to hold 'as depicted'. The Pilot Monitoring (First Officer) put the new holding pattern in the FMGC; a data based hold; and we proceeded to the fix. The FMGC showed a parallel entry and the aircraft turned to enter the holding pattern. Although we entered '10 mile legs' into the FMGC; the aircraft was very slow to intercept the pattern. In fact; after several minutes; the Pilot Flying had to use the heading mode to turn back toward the holding fix. At that time; the Controller inquired if we were turning back toward the fix. By that time we were about 35 miles from HERRI. After proceeding back to HERRI and slowing as much as possible; the aircraft flew the holding track for the hold.There were several factors involved in this event. The weather was a BIG factor. Fort Worth Center cleared us (and several other flights) to hold in an area saturated with thunderstorm cells. In addition we were at a high altitude (36;000 feet) in an A321 and we did not have the option of descending due to aircraft holding below us. Performance of a 321 holding at 36;000 feet is marginal. Another factor; which was a bit of a concern to the crew; was that the FMGC depicted 'managed' holding speed was about 230 knots which was about the same as Vls (lowest selectable airspeed). When the Pilot Flying 'selected' a higher airspeed of approximately 245 knots; the aircraft would not fly the depicted holding pattern. When the higher speed was selected; the aircraft would fly a much larger pattern (over the ground) which prompted the inquiry by the Controller. In this scenario; the crew was caught in a very difficult situation. If the crew flew the holding pattern using 'managed' speed; the aircraft would maintain the holding track but the speed was so slow that we would have almost no stall margin if we had to fly through the edge of any of the severe weather. On the flip side; whenever a higher speed was selected; the aircraft would not fly the published holding pattern.This entire scenario would have been avoided if ATC (Fort Worth Center) had not issued holding instructions at a fix in the vicinity of severe weather. In addition; I recommend that the training department consider developing training for holding at high altitudes; especially in the A321. Many (if not most) Airbus crews believe that; if we keep the aircraft below the maximum holding airspeed; the aircraft will fly the depicted holding pattern. Apparently; that is not the case. As PIC and the 'Flying Pilot'; I learned some important lessons. First; I will not accept a holding pattern when ALL the following conditions exist: 1) A321 & 2) high altitude (above 30;000 feet) & 3) severe weather in the vicinity.


Synopsis: A321 flight crew reports difficulty remaining inside the holding airspace at FL360 when the FMGC is allowed to fly the hold but the speed is increased to 245 knots due to thunderstorms in the area.