P6-340005 – Textron Aviation Momentary Engine Starter Switch
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The P6-340005 is a genuine Textron Aviation (Cessna) OEM, flight-critical momentary toggle switch. This component is the pilot's primary interface for engaging the engine starter. It is a high-cycle, high-reliability switch designed to handle the specific electrical loads of the starter contactor circuit on a wide range of Cessna aircraft.
Engineered for safety and reliability, this is a momentary, spring-loaded switch. The pilot must hold the toggle in the "START" position to engage the starter, and it will automatically spring back to the neutral "OFF" position upon release. This momentary action is a critical safety feature that prevents the starter from remaining engaged with the engine flywheel after the engine has started. The internal contacts are made from high-quality, arc-resistant materials to ensure a long and reliable service life, providing consistent engine starts flight after flight.
Key Features
Genuine Textron Aviation OEM Part: Guarantees perfect electrical compatibility, durability, and fitment as specified in the aircraft's original type design.
Momentary (ON)-OFF Toggle Action: A spring-loaded design that prevents the starter from remaining engaged, protecting both the starter and the engine's ring gear.
Controls the Starter Contactor Circuit: A robust switch designed to reliably handle the inductive load of energizing the high-current starter relay or contactor.
High-Reliability Electrical Contacts: The internal switch contacts are made from a silver-plated copper alloy, designed to resist the electrical arcing and pitting that occurs when switching an inductive load.
Designed for High-Cycle Use: Built to withstand the thousands of actuation cycles required over the life of an aircraft.
Technical Specifications
Part Number: P6-340005
Component Type: Momentary Toggle Switch
OEM Manufacturer: Textron Aviation (Cessna)
Switch Type: Momentary (ON) - OFF, Single-Pole, Single-Throw (SPST).
Electrical Rating: Rated for the specific voltage (14 or 28 VDC) and inductive current load of the starter contactor coil circuit.
Governing Specification: Manufactured to meet or exceed military-grade specifications for toggle switches (e.g., MIL-DTL-3950).
Aircraft Compatibility
The P6-340005 is a standard starter switch used on a vast range of Textron Aviation (Cessna) aircraft, often as part of the key-operated ignition switch assembly or as a standalone toggle. Common applicable models include, but are not limited to:
Cessna 152
Cessna 172 Skyhawk
Cessna 182 Skylane
Various other single-engine and light-twin models.
Crucial Note: The specific aircraft model and serial number must be checked against the latest revision of the official Textron Aviation (Cessna) Illustrated Parts Catalog (IPC) to ensure correct part number applicability.
Applications
Pilot interface for engaging the engine starter motor during the engine start sequence.
Replacement for worn, intermittent, or inoperative starter switches.
Why Choose P6-340005?
Choosing the genuine Textron P6-340005 is a critical decision for the reliability of your aircraft's starting system. The starter switch is subjected to both high cycle counts and the electrical stress of an inductive load. Using a non-certified, commercial-grade switch from an electronics supplier introduces a significant risk of premature failure. The contacts on a lower-quality switch can weld together or erode quickly, leading to an intermittent start condition or a "stuck" starter, which can leave a pilot stranded or cause significant damage to the engine. The genuine OEM part is the only way to guarantee the certified quality and reliability required for this flight-critical application.
The P6-340005 switch is engineered to handle a demanding inductive load. It does not power the high-current starter motor directly; instead, it energizes the coil of the starter contactor, which is a large electromechanical relay. This coil is an inductor, a device that stores energy in a magnetic field. When the pilot releases the momentary starter switch, the circuit to the coil is opened, and its magnetic field collapses. This rapid collapse induces a large reverse-voltage spike across the switch contacts, a phenomenon known as "inductive kick" or "back EMF." This high-voltage potential attempts to sustain the current by creating an electrical arc across the opening switch contacts. The contacts of the P6-340005 switch are made from a specific silver alloy and are designed with a "wiping" action that helps to quench this arc and minimize damage. A lower-quality switch's contacts would be quickly eroded and pitted by this repeated arcing, leading to high resistance, heat buildup, and eventual failure of the switch.
Note: This is a flight-critical engine control component. An inoperative or intermittent starter switch can render the aircraft unserviceable. All electrical work must be performed by a certified A&P or avionics technician in accordance with the Textron/Cessna maintenance and wiring diagram manuals. Ensure all connections are secure and that the switch is properly installed in the panel.
Documentation
The definitive part number applicability and all installation procedures are detailed in the applicable Textron Aviation (Cessna) Illustrated Parts Catalog (IPC) and Wiring Diagram Manual for the specific aircraft model and serial number.