SUNDSTRAND PESCO PUMP ROTARY POWER DRIVEN 025277-300 ACFT EQPT PE-1431

This unit is a high-performance, rotary vane-type hydraulic pump designed for demanding aerospace applications. Part of the classic Sundstrand/Pesco product line, it is engineered to convert mechanical power from an aircraft engine or auxiliary power unit (APU) into hydraulic power for flight-critical systems.

SERIAL NO: PE-1431

MODEL: 025277-300

PARTS LIST NO: 025277-307

UACL NO: CPW-3028125

ACFT EQPT DIV SUNDSTRAND CORP

• Manufacturer: Sundstrand Corporation (later Sundstrand Aerospace, now part of Collins Aerospace under Raytheon Technologies). The “PESCO” name denotes its origin from the Pump Engineering Service Corporation, a pioneer acquired by Sundstrand.
• Part Number: 025277-300 (This is the specific engineering/manufacturing part number).
• NSN / Government Designation: PE-1431 (This is a standard U.S. Government/Federal Stock Code identifying it as a Pump, Engine Driven, Hydraulic, with this specific design).
• Type: Rotary, Power Driven, Constant Displacement (most likely). It is a positive displacement pump.

• Flight control actuators (ailerons, rudder, elevators)
• Landing gear actuation and braking systems
• Wing flap and slat drives
• Cargo door or ramp actuators
• Other utility hydraulic functions.

• Drive Mechanism: Power Driven. It is designed to be mounted to and directly driven by an aircraft engine accessory gearbox, an APU gearbox, or an electric motor. The input drive is typically a splined shaft.
• Pump Principle: Rotary Vane. The pump uses a slotted rotor with sliding vanes inside a cam-shaped housing. Centrifugal force and hydraulic pressure push the vanes outward, creating sealed chambers that increase in volume (suction) and decrease in volume (discharge) to generate smooth, continuous flow.
• Construction: Built from high-strength, lightweight materials (typically aluminum housings, steel rotors and shafts) for aerospace use. Features robust bearings and seals to handle high speeds and pressures.
• Performance: Characterized by high power-to-weight ratio, reliable operation at various aircraft altitudes and temperatures, and capability for sustained high-pressure output (common pressures are 3,000 psi / 207 bar).
• Porting: Will have defined Pressure (Outlet), Suction (Inlet), and Case Drain ports. The case drain returns internal leakage fluid to the reservoir, essential for maintaining pump health and monitoring wear.

• C-130 Hercules (various hydraulic systems)
• F-4 Phantom II
• Boeing 707 / KC-135 families
• DC-8 / DC-9 aircraft
• Various business jets and military trainers.

• Maintenance: Requires strict adherence to aircraft maintenance manuals (e.g., CMM – Component Maintenance Manual). Regular inspection for metal particles in filters and case drain flow checks are critical.
• Fluid Compatibility: Must use the aircraft-specified hydraulic fluid. Contamination control is paramount.
• Status: This is a legacy part. While still supported through overhaul programs and aftermarket suppliers, it is likely out of new production. PE-1431 and 025277-300 are well-known numbers in the aerospace supply chain.
• Certification: Originally manufactured under stringent FAA / EASA / Military standards (e.g., TSO, PMA).