A319 first officer reported loss of hydraulic fluid and an associated pitch down resulted in a prior...

Narrative:

During cruise at FL320 ECAM showed hydraulic Y sys lo and quantity indicated zero. Accomplished ECAM actions in accordance with checklists and advised dispatch and maintenance control. Elected to continue to ZZZ. During descent on autopilot aircraft abruptly pitched down; autopilot disconnected and ECAM momentarily showed hydb + Y sys lo pr.recovered aircraft from pitch down and [requested priority handling] with mayday call. The ECAM hydraulic B 'self-healed' and disappeared from ECAM display. We used the 7700 ACARS feature to notify dispatch. Apparently; it did not work according to our dispatcher. Accomplished non-routine landing considerations checklist; coordinating with cabin crew and ATC. Did not re-engage autopilot for the remainder of the flight and hand flew the approach. There is a discrepancy between ECAM and the manual on turning on Y system engine pump during approach. We chose the ECAM guidance and turned on the pump after configuring.we expected only one reverse on rollout; but had indications of normal reverse on both engines. Taxied to gate with [crash fire rescue equipment] following. Terminated emergency with ground after shutdown. On post flight; first officer found fluid covering the bottom of the airplane; in the left wheel well and on the left main landing gear. During the van ride to our layover hotel; the flight attendants told us a burning mechanical smell in mid cabin occurred soon after the pitch down.

Original NASA ASRS Text

Title: A319 First Officer reported loss of hydraulic fluid and an associated pitch down resulted in a priority landing.

Narrative: During cruise at FL320 ECAM showed HYD Y sys lo and quantity indicated zero. Accomplished ECAM actions in accordance with checklists and advised Dispatch and Maintenance Control. Elected to continue to ZZZ. During descent on autopilot aircraft abruptly pitched down; autopilot disconnected and ECAM momentarily showed HYDB + Y sys lo pr.Recovered aircraft from pitch down and [Requested Priority Handling] with mayday call. The ECAM HYD B 'self-healed' and disappeared from ECAM display. We used the 7700 ACARS feature to notify Dispatch. Apparently; it did not work according to our Dispatcher. Accomplished non-routine landing considerations checklist; coordinating with cabin crew and ATC. Did not re-engage autopilot for the remainder of the flight and hand flew the approach. There is a discrepancy between ECAM and the manual on turning on Y system engine pump during approach. We chose the ECAM guidance and turned on the pump after configuring.We expected only one reverse on rollout; but had indications of normal reverse on both engines. Taxied to gate with [Crash Fire Rescue Equipment] following. Terminated emergency with ground after shutdown. On post flight; First Officer found fluid covering the bottom of the airplane; in the left wheel well and on the left main landing gear. During the van ride to our layover hotel; the Flight Attendants told us a burning mechanical smell in mid cabin occurred soon after the pitch down.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1691868
Time
Date	201910
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Hydraulic Main System
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

A319 first officer reported loss of hydraulic fluid and an associated pitch down resulted in a priority landing.