What is ADP on Boeing 777? (Air Driven Pump)

How does the Air Driven Pump work?

The Air Driven Pump on the Boeing 777 operates by utilizing high-pressure air from the aircraft’s pneumatic system. This air passes through a series of valves and regulators before reaching the ADP. Once the air enters the pump, it drives a piston or diaphragm, which in turn pressurizes hydraulic fluid.

The pressurized hydraulic fluid is then directed to various hydraulic systems and actuators, assisting in the movement of control surfaces, extending/retracting the landing gear, and enabling smooth braking operations. The ADP can generate hydraulic pressures of up to 3,000 psi (pounds per square inch), ensuring sufficient power to operate all necessary hydraulic functions.

The ADP also incorporates safety features to prevent over-pressurization and damage to the system. These safety mechanisms include relief valves and pressure sensors, which continuously monitor and regulate hydraulic pressure within optimal limits. In the event of excessive pressure buildup, the relief valves open to release the excess pressure, maintaining the integrity and functionality of the ADP.

Importance and Reliability of the Air Driven Pump

The Air Driven Pump is a critical component in the Boeing 777, ensuring the availability of hydraulic power even in the face of primary system failures. Its importance lies in its ability to provide redundancy, allowing the aircraft to continue operating safely and minimizing the potential impact on flight operations.

Notably, the ADP’s reliability is a testament to Boeing’s rigorous engineering and testing processes. The ADP undergoes extensive simulations, stress testing, and real-world scenarios to ensure it can perform flawlessly when needed. Boeing engineers analyze the pump’s performance under various conditions, such as extreme temperatures, high-altitude operations, and emergency scenarios.

Furthermore, the ADP undergoes regular inspections and maintenance checks to ensure its continued functionality. Boeing’s maintenance programs abide by strict guidelines and schedules, with qualified technicians closely monitoring and servicing the ADP at specified intervals. This proactive approach prevents potential issues and guarantees the reliability of the ADP during every flight.


The Air Driven Pump (ADP) on the Boeing 777 is a vital component that ensures the availability of hydraulic power in case of primary system failures. With its capability to generate high-pressure hydraulic power using air pressure, the ADP guarantees the safe operation of critical systems in the aircraft, including landing gear, flight controls, and brakes.

Boeing’s commitment to engineering excellence and rigorous testing processes ensures the reliability of the ADP. It undergoes extensive simulations and testing to perform flawlessly in various operating conditions. Regular inspections and maintenance also contribute to the ADP’s continuous functionality and reliability.

The Air Driven Pump is just one example of the advanced systems and components incorporated into the Boeing 777, further solidifying its reputation as a leading aircraft in the industry.

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