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131 Series Auxiliary Power Units

Overview
The 131-9 Auxiliary Power Unit (APU) introduced a two-stage axial turbine for longer engine life and a single starter/generator that uses electrical power to start the APU, and then becomes a generator once it’s running. This has led to the 131 Series becoming one of the most successful APUs with more than 100 million hours of in-service use.

Honeywell has released a high efficiency mode (HEM) upgrade for the 131-9A Auxiliary Power Unit for single-aisle Airbus aircraft and 131-9B Auxiliary Power Unit for single-aisle Boeing aircraft. HEM supports airlines in achieving greater fuel-efficiency, reduced carbon emissions, improved time on wing, and compliance with more stringent regulatory guidelines. It was also chosen for the Bombardier C-Series.

The powerful combination of hardware and advanced software deliver HEM benefits that improve operational and bottom-line performance for operators. The redesigned diffuser is critical, but it’s the software that autonomously controls the diffuser to regulate airflow into the compressor section. As a result, the engine burns fuel more efficiently at lower temperatures, which reduces wear and tear on critical engine parts.

Compatible Platform

Bell 429
Boeing AH-64 Apache
Lockheed Martin C-130 Hercules
Pilatus PC-12 NG
Pilatus PC-12 NGX
Sikorsky H-60

Specifications

  • Key Benefits

    • 1-2% improvement in fuel efficiency
    • Easy installation
    • Improved environmental performance, reducing carbon dioxide emissions
    • Reduced overall maintenance costs and lower spares requirements, thanks to longer time-on-wing
    • Reduces carbon dioxide emissions by up to 22 metric tons per APU per year, depending on operating conditions
  • Key Benefits

    • 1-2% improvement in fuel efficiency
    • Easy installation
    • Improved environmental performance, reducing carbon dioxide emissions
    • Reduced overall maintenance costs and lower spares requirements, thanks to longer time-on-wing
    • Reduces carbon dioxide emissions by up to 22 metric tons per APU per year, depending on operating conditions

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18 Mar 2026
2.14 MB
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18 Mar 2026
2.14 MB
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