Date: 202109
Local time of day: 0601-1200
Location: PHX.Tower, AZ
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class B PHX
ATC / advisory: Tower PHX
Second aircraft: A320
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Anomaly: Deviation - Speed All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Regained Aircraft Control
Contributing factors: Environment - Non Weather Related; Procedure
Primary problem: Procedure

Narrative: I was the Pilot Monitoring on the flight. The F/O (First Officer) was the Pilot Flying during the event. It was day VMC with no adverse weather and light easterly winds. Autothrottle with LNAV/VNAV modes were engaged on the flight director; but the PF was hand flying throughout the event. Thrust was reduced to Level 2 for take off.We were departing PHX 7L on the FYRBD 1 RNAV Departure.  ATC cleared us for takeoff to visually follow an A320.  When we rotated off; the A320 was about 3-4 miles ahead of us climbing out on a different departure that departed to the southeast; but had a similar track initially. We experienced the first wake roll encounter just before selecting flaps up; about 900'-1;000' AGL; the aircraft rolled about 20-30 degrees and the PF was able to counter and stop the roll with full aileron deflection but it stayed in the bank about three seconds before returning to wings level. I could feel light air frame buffeting from roll spoilers being fully deployed. He called for flaps up. I selected flaps up and the aircraft encountered the wake again and rolled the opposite direction; again the PF corrected with full aileron deflection and I could feel the spoilers deploy; the aircraft had a more noticeable buffet; speed stagnated and began to decrease towards flaps up V min maneuver speed (yellow speed tape band). The flaps were retracting as this happened and the min maneuver speed (yellow band) was increasing. I immediately saw the pitch limit indicators appear and quickly descend to almost touch the flight path indicators; indicating we were approaching a high AOA (Angle Of Attack) and close to stall. I said to the PF to lower the nose and increase speed; which he was doing as I said it. I deleted the reduced climb setting in the FMC and the engines went to climb power; I am not sure why neither of us didn't just push the thrust levers up. (Distraction? surprise factor?) The speed stabilized just above V min and began to increase as the aircraft rolled to wings level. We gained about 10 knots in speed when we again encountered the wake; the aircraft rolled again to about 30 degrees despite the PF applying full aileron to counter it. Again with full roll spoiler out; the speed stagnated; we could feel buffet and the aircraft stayed in the banked condition for 2-5 seconds before responding to the control inputs. Again wings level the speed began to increase and we continued on the departure path. The preceding aircraft diverged from our course and we then continued with no further events. While ATC may have provided the minimum separation; we clearly needed more than what was provided. I have not experienced this type of encounter following an A320 ever.  Usually it is a 757-767 type or larger. In hindsight; we should have performed the nose high upset recover maneuver and manually applied full thrust. I think the fact we routinely experience some wake events with only minor attitude changes led us to not react as we should have. The reduced climb thrust setting placed us in the A320 wake longer and hampered our recovery. Higher initial climb thrust would have allowed us to out climb or at least experience less airspeed stagnation.

Callback: Reporter stated he was surprised at the intensity of the A320 wake.



Synopsis: B737-800 Captain reported encountering wake turbulence departing PHX in trail of an A320.