B737 flight crew reported loss of hydraulic system a fluid and pressure.

Attributes
ACN	1436082
Time
Date	201703
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Hydraulic Main System
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 201
Person 2
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 162 Flight Crew Type 2300
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Prior to top of descent we experienced a low pressure light on engine 1 hydraulics. We accomplished QRH and informed maintenance [via] ACARS. Shortly after reporting we noticed intermittent lights on electric pump 1 and flight control a. System a read zero quantity and system pressure cycled between 0 and 2925 psi. This happened throughout descent; and upon leveling at 9000 MSL the light became steadier.we surmised a total loss of hydraulic system a and went back into the QRH. We coordinated with approach control for extended final visual to allow time for gear extension. Upon landing we extended the rollout to avoid excessive braking and side loading upon turnoff. We then parked awaiting inspection from fire/rescue. We were towed to gate. No reported passenger or crew injuries.

Original NASA ASRS Text

Title: B737 flight crew reported loss of hydraulic system A fluid and pressure.

Narrative: Prior to Top of Descent we experienced a Low Pressure light on engine 1 hydraulics. We accomplished QRH and informed Maintenance [via] ACARS. Shortly after reporting we noticed intermittent lights on electric pump 1 and Flight Control A. System A read zero quantity and system pressure cycled between 0 and 2925 psi. This happened throughout descent; and upon leveling at 9000 MSL the light became steadier.We surmised a total loss of hydraulic system A and went back into the QRH. We coordinated with Approach Control for extended final visual to allow time for gear extension. Upon landing we extended the rollout to avoid excessive braking and side loading upon turnoff. We then parked awaiting inspection from Fire/Rescue. We were towed to gate. No reported passenger or crew injuries.

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.