587-779 – Piper Aircraft OEM Micro Switch
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Overview
The 587-779 is a flight-critical, genuine Piper Aircraft Original Equipment Manufacturer (OEM) miniature snap-action switch, commonly known as a micro switch. This component is engineered for high-reliability position sensing within various critical aircraft systems. Its primary function is to detect the mechanical position of components such as landing gear linkages, flap actuators, or door mechanisms, and translate that position into a precise electrical signal for cockpit indication or system logic control.
Manufactured to Piper's stringent specifications, often utilizing a robust Honeywell switch as the base component, the 587-779 features a snap-action mechanism. This design ensures a rapid and positive transfer of electrical contacts, providing a clean, unambiguous signal independent of the speed at which the switch is actuated. As the genuine OEM part, it guarantees the correct actuation force, travel characteristics, electrical ratings, and environmental resistance required for safe and reliable operation.
Key Features
Genuine Piper Aircraft OEM Part: Guarantees the switch is the factory-specified and fully certified component, ensuring correct performance and airworthiness.
Flight-Critical Position Sensing: Used in essential systems like landing gear and flaps, where accurate position indication is paramount for safety.
Snap-Action Mechanism: An internal over-center spring provides rapid, positive contact transfer, ensuring reliable switching, long contact life, and resistance to contact bounce or teasing.
High Reliability & Durability: Engineered for demanding aerospace applications with robust internal components and construction designed to withstand vibration and environmental factors.
Precise Actuation Points: Manufactured to activate and deactivate at specific, repeatable plunger or lever travel points critical for system timing and logic.
Compact Miniature Design: Allows for installation in space-constrained areas within the airframe.
Technical Specifications
Part Number: 587-779
Component Type: Miniature Snap-Action Switch (Micro Switch) / Limit Switch
OEM Authority: Piper Aircraft
Underlying Manufacturer (Typical): Honeywell Sensing and Control or equivalent approved source.
Application: Position Sensing (Landing Gear, Flaps, Doors, etc.)
Actuator: Per Piper specification (commonly Pin Plunger or Lever type). Must be confirmed by Piper documentation.
Circuitry: Typically SPDT (Single Pole, Double Throw - Common, Normally Open, Normally Closed). Must be confirmed by Piper documentation.
Electrical Rating: Per Piper specification (e.g., 5 Amps @ 28 VDC). Must be confirmed by Piper documentation.
Governing Specification: Piper Aircraft Engineering Drawing 587-779.
Aircraft Compatibility
This OEM micro switch is specified for numerous critical position-sensing applications across a wide range of Piper aircraft, particularly retractable gear models.
Primary Piper Aircraft Platforms:
PA-28R Series (Arrow)
PA-32R Series (Lance, Saratoga)
PA-34 Seneca
PA-44 Seminole
PA-46 Series (Malibu, Mirage, Matrix, M-Class)
Other models as specified in the IPC.
Note: Verification of applicability is the absolute responsibility of the installer. The aircraft's current Illustrated Parts Catalog (IPC) for its specific serial number is the final authority for confirming part number eligibility.
Applications
Landing Gear Systems: Up-lock sensing, down-lock sensing, squat switch (weight-on-wheels), gear door position indication.
Flap Systems: Flap position indication (degrees of extension or transit).
Door/Canopy Systems: Cabin door, baggage door, or canopy closed-and-latched indication.
Other Systems: May be used in throttle quadrant (idle/takeoff power sensing), control lock sensing, or other applications requiring precise mechanical position detection.
Why Choose 587-779?
The failure of a position-sensing switch in a critical system like landing gear can lead to unsafe operating conditions, gear-up landings, or inability to retract the gear. The genuine Piper OEM 587-779 is the only switch guaranteed to meet the specific actuation force, travel parameters, electrical ratings, and environmental qualifications required by the aircraft's certified design. Using a generic, non-certified switch risks incorrect system operation (e.g., unsafe gear indication), false warnings, or premature failure, directly compromising flight safety.
The high reliability of the 587-779 switch is significantly enhanced by its snap-action, over-center mechanism. Inside the switch, a pre-stressed beryllium copper spring is held in one of two stable positions. As the external actuator moves, it applies force to the spring. When the actuator's travel reaches a precisely defined "trip point," it pushes the spring past its geometric center. This causes the stored mechanical energy to be released almost instantaneously, forcing the movable electrical contact to "snap" to its opposite terminal with high speed and force, independent of how slowly the actuator was moved. This rapid transfer minimizes the duration of any electrical arc between the contacts as they make or break, drastically reducing contact erosion and heat generation. Furthermore, the positive snap provides excellent resistance to contact "teasing" or chatter under vibration, ensuring a clean, reliable electrical signal essential for interfacing with aircraft systems.
Note: This is a flight-critical component. Installation, adjustment (rigging), and testing must be performed by a certified A&P mechanic in strict accordance with the Piper aircraft maintenance manual and wiring diagrams. Correct installation ensures the switch is actuated at the precise point in the mechanism's travel. Post-installation functional testing of the associated system (e.g., landing gear swing, flap operation check) is mandatory before flight.
Documentation
No public-facing OEM or regulatory documentation was located for this specific part number. All technical data, including specific electrical ratings, actuator type, installation procedures, and rigging specifications for the 587-779 switch, are proprietary to Piper Aircraft. This information is contained within the official Maintenance Manual, Wiring Diagram Manual, and Illustrated Parts Catalog for the applicable aircraft model.