What is ADP on Boeing 737? (Air Driven Pump)

On the Boeing 737 aircraft, an important component known as the Air Driven Pump (ADP) plays a crucial role in the hydraulic system. The ADP is designed to provide backup hydraulic pressure in the event of a power loss or failure of the main engine-driven pumps. By utilizing compressed air, the ADP ensures that essential hydraulic functions can be maintained, allowing for safe and reliable operation of the aircraft.

How Does the Air Driven Pump Work?

The Air Driven Pump on the Boeing 737 operates based on a simple yet efficient principle. When the aircraft’s hydraulic system requires additional pressure due to a power loss, the ADP comes into action. It utilizes compressed air from the aircraft’s pneumatic system to drive a turbine and generate mechanical energy.

This mechanical energy is then transferred to a hydraulic piston, which pressurizes the hydraulic fluid and supplies it to the required systems. The ADP is controlled by the aircraft’s hydraulic system, which regulates its operation based on the demand for hydraulic pressure.

Advantages and Benefits of Air Driven Pump

The Air Driven Pump offers several advantages and benefits for the Boeing 737 aircraft. Here are some key advantages:

1. Redundancy and Reliability

The ADP provides redundancy in the hydraulic system, ensuring that hydraulic pressure can be maintained even in the event of a failure of the main engine-driven pumps. This redundancy enhances the reliability of the aircraft’s hydraulic system and contributes to its overall safety.

The Air Driven Pump is designed to operate in various failure scenarios, including engine failures, power loss, or mechanical malfunctions. With its ability to work independently of the primary power sources, the ADP acts as a reliable backup, safeguarding critical hydraulic functions.

Additionally, the ADP is built with robust and durable components, ensuring its longevity and performance even in demanding operating conditions. Its reliability is crucial for the safe operation of the Boeing 737 aircraft.

2. Lightweight Design

The Air Driven Pump is engineered with a lightweight design, which is essential for aircraft operations. By minimizing weight, the ADP contributes to fuel efficiency and overall performance.

Reducing weight is a critical consideration for aircraft manufacturers, as it directly impacts fuel consumption and operational costs. The lightweight design of the ADP allows the Boeing 737 to optimize its fuel efficiency, resulting in reduced emissions and lower operational expenses.

3. Cost-Effective Maintenance

Another advantage of the Air Driven Pump is its cost-effective maintenance. Compared to other hydraulic components, the ADP requires relatively simpler maintenance procedures.

The ADP’s robust design and fewer moving parts contribute to its reduced maintenance requirements. This results in lower maintenance costs and shorter maintenance downtime for the aircraft. The simplified maintenance procedures associated with the ADP make it an attractive choice for Boeing 737 operators.


The Air Driven Pump (ADP) is a vital component of the hydraulic system on the Boeing 737 aircraft. Its ability to provide backup hydraulic pressure in the event of power loss or failure of the main engine-driven pumps ensures the safe and reliable operation of the aircraft.

The ADP’s redundancy, lightweight design, and cost-effective maintenance contribute to its effectiveness and efficiency. By incorporating the Air Driven Pump into the hydraulic system, the Boeing 737 enhances its reliability, fuel efficiency, and overall performance.

Understanding the importance and functioning of the Air Driven Pump allows for a deeper appreciation of the intricate systems that enable the Boeing 737 to fly smoothly and with utmost safety.

For More: What is TMS on Boeing 737? (Thrust Management System)