Honeywell upgraded its auxiliary power unit (APU) on the Boeing 737 aircraft, known as High Efficiency Mode, or HEM enabling it to reduce CO2 emissions by up to 2%, increasing efficiency and minimising fuel consumption.
Heath Patrick, president, Honeywell Aerospace, said: “An airline with a fleet of 50 737s could realise as much as $450,000 in annual fuel savings and reduce its emissions by up to 1,100 metric tons of CO2, depending on operating conditions.”
HEM is enabled by a “highly efficient” diffuser, controlled by intelligent software which regulates airflow to the APU compressor section, says Honeywell.
The upgrade is intended for any aircraft already operating a 131-9BAPU, including Boeing 737-600, 737-700, 737-800, 737-900 and 737 MAX models. It will be available to operators with 131-9B APUs in the second half of this year. Honeywell notes that the upgrade can be installed during any regularly scheduled maintenance event and does not require additional downtime to implement.
The HEM upgrade was previously introduced on the Airbus A320 Series aircraft in 2020 and is now installed on over 700 131-9A APUs.