23048-018 - Textron Aviation OEM Goodrich Starter Generator 250 Amp 28 Volts DC

23048-018 – Textron Aviation OEM Starter-Generator for King Air Aircraft

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Overview

The Textron Aviation 23048-018 is an OEM, flight-critical DC starter-generator designed for the demanding environment of the Beechcraft King Air series of twin-turboprop aircraft. This heavy-duty, dual-function rotating machine is a cornerstone of the aircraft's electrical and engine start systems. In its "starter" mode, it functions as a high-torque DC electric motor, drawing heavy current from the aircraft's battery or a ground power unit to spool the Pratt & Whitney Canada PT6A turbine engine to its self-sustaining speed. Upon engine start, its function seamlessly transitions to "generator" mode. Driven by the engine's accessory gearbox, it becomes the primary source of 28 VDC electrical power for the aircraft, supplying current to all onboard avionics, lighting, and environmental systems while simultaneously recharging the aircraft's battery.

Engineered for exceptional reliability and a long service life, the 23048-018 is built to withstand extreme operating temperatures, high altitudes, and the constant vibration of the engine environment. Its design incorporates features such as a splined drive shaft for positive engagement with the engine gearbox, a cooling air blast tube connection, and a quick-attach/detach (QAD) V-band clamp for simplified maintenance. As the heart of the electrical system, the performance and airworthiness of this component are paramount to the safety and mission capability of the aircraft.

Key Features

• OEM Certification: Genuine Textron Aviation part (manufactured by Safran Power/Skurka Aerospace/Goodrich), ensuring original performance, reliability, and airworthiness.
• Dual-Functionality: Operates as a high-torque series-wound motor for engine starting and a compound-wound generator for electrical power supply.
• High Power Output: Rated to produce a continuous output of 250 or 300 Amperes at 28 VDC, depending on the specific dash number configuration.
• Forced-Air Cooled: Designed with an integral fan and blast tube connection for effective cooling, ensuring reliability under high electrical loads.
• Long-Life Brushes: Utilizes high-altitude carbon brushes designed for extended wear life and optimal commutation.
• Heavy-Duty Construction: Built with a rugged, vibration-resistant housing, high-temperature windings, and precision bearings for maximum durability.

Technical Specifications

• Part Number: 23048-018
• Component Type: DC Starter-Generator
• OEM Manufacturer: Safran Power Systems (formerly Goodrich, Lucas Aerospace, Skurka Aerospace). This is the OEM supplier to Textron Aviation.
• Voltage Rating: 28 VDC
• Current Rating (Generator Mode): 250 Amps (Continuous)
• Speed Range: Typically 8,000 - 12,000 RPM for regulated voltage output.
• Rotation: Clockwise (CW)
• Mounting: Quick-Attach/Detach (QAD) V-Band Clamp
• Drive Shaft: Splined Shaft, typically conforming to AND20002 Type XV-B
• Governing Specifications: Certified to FAA TSO-C56b standards.

CORE ACCEPTABILITY LIST - The following core part numbers are accepted for core return. No other part number is accepted:

• 100-389005-11
• 23048-018

Aircraft Compatibility

• Textron Aviation (Beechcraft): 
• • King Air 100 (BE-1 and after)
  • King Air C90
  • King Air C90A
  • King Air C90GT
  • King Air E90
  • King Air C90GTi
  • King Air C90GTx (Serials pre SB24-3374)

Note: This list is for reference only and may not be exhaustive. The specific aircraft Illustrated Parts Catalog (IPC) and Component Maintenance Manual (CMM) are the final authorities for determining part applicability and interchangeability for a given aircraft serial number.

Applications

• Engine Starting: Provides the mechanical torque required to accelerate the PT6A gas turbine engine's compressor section from rest to ignition and self-sustaining RPM.
• Primary Electrical Power Generation: Supplies 28 VDC current to the aircraft's main electrical busses to power all systems during flight.
• Battery Charging: Maintains the charge of the aircraft's main battery (or batteries).

Why Choose 23048-018?

The starter-generator is one of the hardest working components on a turboprop aircraft. Choosing a genuine OEM 23048-018, manufactured by the original supplier (Safran/Skurka), is a critical decision for safety and reliability. Improperly overhauled or non-certified units can suffer from premature brush wear, bearing failure, or insulation breakdown, leading to in-flight electrical failure, an inability to start an engine, or even an electrical fire. This certified part guarantees the correct materials, manufacturing processes, and quality control, ensuring it will perform as designed under the most demanding flight conditions, safeguarding the crew, passengers, and the mission.

The 23048-018 is a compound-wound DC machine, a sophisticated design that optimizes its dual-role performance. During engine start, it functions as a series motor. The high-current armature winding and the heavy-gauge series field winding are connected in series, producing the massive starting torque required to overcome the PT6A engine's inertia. As the starter accelerates, the counter-electromotive force (CEMF) increases, naturally reducing the current draw. Once the engine lights off and reaches a self-sustaining speed, the generator control unit (GCU) switches the field winding configuration. In generator mode, both a shunt field winding (parallel to the armature) and the series field winding are used. This compound winding provides superior voltage regulation under varying electrical loads. The dominant shunt field establishes the primary magnetic field, while the series field, through which the generator's output current flows, creates a magnetic field that strengthens in proportion to the load. This effect counteracts the armature reaction and voltage drop, resulting in a remarkably stable 28 VDC output across the aircraft's full operational envelope.

Note: The 23048-018 is a flight-critical component that requires periodic inspection of brushes and bearings as a time-limited item. Installation, removal, and maintenance must be performed by a certified A&P mechanic in strict accordance with the current Textron Aviation King Air maintenance manual. All electrical connections must be clean, dry, and torqued to the specified values to prevent fire hazards.

Documentation

No public-facing OEM Component Maintenance Manual (CMM) was located for this part. All technical data, including overhaul procedures, testing criteria, and service limits, are proprietary to the OEM (Safran Power Systems/Skurka Aerospace) and are available to certified repair facilities. For operational and functional testing on the aircraft, refer to the applicable Beechcraft King Air Aircraft Maintenance Manual (AMM).

CLICK THIS LINK FOR A GREAT ARTICLE FROM KING AIR MAGAZINE REGARDING 23048-018