2011-08 · NASA ASRS report 967232
A319 flight crew experiences an FMGC anomaly during descent on the KOOLY 3 RNAV arrival to PHX; resulting in descent below profile and speed above 280 KTS at 7;400 FT.
We were cleared to descend on the KOOLY 3 arrival Runway 25L into Phoenix. The aircraft was in managed descent mode and had been on speed and making all altitude restrictions. We had just been switched from ABQ Center to Phoenix Approach. We had descended through 10;000 FT and were at 250 KTS. I was setting the PHX Approach frequency for the First Officer; but I could not get .65 to display; only .75 or .55. We were both distracted by number 1 radio not displaying the .6 for about 45 seconds or so. When I looked at the aircraft profile; I saw that we had passed the deceleration point and the FMGC was commanding a speed reduction to approach speed. I pulled the speed knob to stop the aircraft form slowing; but I noticed the aircraft was actually accelerating through 280 KTS. I saw that the aircraft had gone into vertical speed and was descending at 3;600 FPM. I turned off the autopilot and stopped the descent at 7;100 FT and realized we were below the 8;000 FT altitude restriction at PUKRE. I climbed up to 8;000 FT and slowed the aircraft to 210 KTS. We contacted PHX Approach and the Controller did not question our altitude; but did say to slow to 210 KTS; which we had already done. There had been no changes to the MCDU or the FCU. I have no idea why the aircraft went into vertical speed. If I had not been distracted by the radio display; I may have been able to stop the aircraft form going into vertical speed or at least not allowed the aircraft to continue to descend in vertical speed.
On the KOOLY 3 Arrival we were cleared to descend via the KOOLY 3 Runway 25L transition. Passing CABOS fix with an altitude of 10;000 FT and 250 KTS; we were given a frequency change to 126.65 for PHX Approach. Both pilots were distracted by the #1 radio digits would not dial in the .6 of the frequency; jumping from .5 to .7 and back without indicating a .6. The aircraft automatically 'Activated and Confirmed' then began to slow to 127 KTS. Captain pulled Selected Speed to dial in 210 KTS. In the meantime; the KOOLY arrival usually shows a 'Too Steep Descent' after CABOS to PUKRE; the Managed Descent mode switched to a Vertical Speed descent at 3;600 FPM in an effort to dive to catch the descent profile to make the PUKRE restrictions of 8;000 FT-10;000 FT and 210 KTS. The Vertical Speed change and resulting dive caused the airspeed to increase above 280 KTS when we caught the mode change at our below constraint altitude of 7;400 FT. The Managed Descent mode should not have allowed descent below 8;000 for PUKRE which is the low end of the constraint window. We violated altitude and airspeed in this unexpected descent mode change.
More incidents for this aircraft family
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.
Loading the flight search…
Pick an aircraft model — Boeing 737, Airbus A320, A380, Boeing 787 Dreamliner and more — enter your origin airport, and FlightFinder shows every route that plane flies from there with live fares.
We support Boeing 737/747/757/767/777/787, the full Airbus A220/A319/A320/A321/A330/A340/A350/A380 family, Embraer E170/E175/E190/E195, Bombardier CRJ and Dash 8, and the ATR 42/72 turboprops.
Search and schedules are free. Pro ($4.99/month, $39/year, or $99 one-time lifetime) unlocks the enriched flight card — on-time stats, CO₂ per passenger, amenities, live gate & weather — plus My Trips with push alerts.
Live schedules come from Amadeus, AeroDataBox and Travelpayouts. Observed routes (which aircraft actually flew a given city pair) are crowdsourced from adsb.lol ADS-B data under the Open Database License.